The "Look"... Update 2/5/2024
I watched a couple of pickup truck related events on Youtube recently. The first photo here was screenshot from the 2023 Hot Rod Powertour video while the tour was in eastern Tennessee and the other was from a video about a Chevy C10 group event that was sponsored by LMC Trucks. I saw a couple of trucks while watching the videos that made me hit the rewind button.... :)
https://www.thedieselpageforums.com/...7&d=1707160066
https://www.thedieselpageforums.com/...8&d=1707160066
Though Lil Red is now 35 years old (but 20 years in its present form), it seems some of the design elements may have appealed to a couple of other truck builders. I think its cool. ;)
Jim
Update - 2/28/2024 - Purple Power!
https://www.thedieselpageforums.com/...9&d=1709154546
The power increases eventually reached the limits of the factory Allison. In working with Kennedy and ATS, we came to the conclusion that the "ATS Extreme" Allison would be a step in the right direction. It has been. While the original factory Allison could be made to slip with 500-hp and a power-brake launch at the strip, the ATS has yet to slip, even with more than 600 hp. The torque converter contains a 5-disk pack that provides for a solid connection once locked.
https://www.thedieselpageforums.com/...0&d=1709154546
A note about this image... Originally, I used smoke-tinted covers for both the headlight lenses and turn signal lenses. I would then remove the smoke tinted headlight covers if/when the truck was driven in the evening or at night (very rarely). The covers were employed only during during the daylight hours. Because removing/replacing the covers was a royal PITA, I have since replaced the tinted covers with DOT tinted headlight lenses and tinted turn signal lenses. I did give up a small amount of illumination in exchange for a better match for my patience. ;)
A local friend who also just happens to own a mechanics garage (and is a transmission expert), worked with me to install the new ATS Allison. The lift makes this sort of thing so easy, when compared to a transmission floor jack and jack stands...
Shift quality while using performance programming was pretty "performance oriented", sometimes producing a little "bark" from the rear tires at gear changes while on local highways. Who can resist using a little pedal? ;) But, when toning down the ECM programming to near stock levels, the ATS Allison gets real close to factory Allison shift quality.
I've not had any code setting with this transmission - or any other problem. There's only about 12K miles on it since installation, and the ATF fluid remains nice. The transmission has seen only a couple of dozen 1/4-mile runs and a similar number of dyno runs so far, plus highway driving. But, I do plan to service the transmission this coming spring - new spin-on filter and pan filter, plus a fluid drain/refill. I'll report back once that's been completed... if we find anything unusual. Jim
Update 3-21-2024 - Diesel Performance!
This video was produced some years ago, before diesel performance programming could produce power without smoke and while tires were a bit less expensive than they are now. ;) Mind you, something similar to what's shown here can be seen today on nearly any performance automotive cable program or related Youtube channel. So... Lil Red hasn't produced smoke in years and tires are currently viewed as a more longer term investment...
https://www.youtube.com/watch?v=EO46o2_VrlY
Except for imagining vvrrrooommm sounds, there is no audio. However, no pedestrians or cute bunnies were harmed in the making of this film. :o
The following image was shot a few months after the above video was taken, only this time I was using a KennedyDiesel.com EFI-Live program that allowed the truck to dyno 500-rwhp. As you can see, there is no visible smoke shown here at the beginning of a 1/4-mile run. ;)
I was likely using a Van-Aaken performance module when the smokey burnout video was made. I liked that in-line module when used at lower power (no smoke) settings, and I used it for years in my 2001 GMC Duramax crew cab where it could smoothly produce more than 400 rwhp without smoke.
https://www.thedieselpage.com/features/atstrans08.jpg
Back in the early days of the Duramax I answered a few emails from young guys who wanted ideas for how to get their truck to produce more smoke... I tried to discourage the idea...
4/1/2024 Update - Checklists
When beginning a project as complex as a Duramax conversion, it's helpful as you work through the project to use checklists, and then concentrate on one or just a few steps at a time. A person can become bogged-down and discouraged when contemplating the entirety of the project. Again, just concentrating on a few steps at a time helps to keep you focused, and allows you to see and measure progress in real terms.
When Lil Red was still in the planning stages, and later while actually working through the conversion, I created many lists that I used to help keep me focused. Shown below is just one of those lists (yes, I kept them all). Some of the lists, notes and hand-drawn diagrams were later refined and then included the "Duramax Conversion Guide". Aside from helping me as the conversion was taking shape, some of this information could be helpful if a problem appears months/years later. Knowing the details can aid in troubleshooting.
http://www.thedieselpageforums.com/p...ecklist002.jpg
When taken as bite-size chunks, the project becomes more doable for most people. And a list helps to keep you focused.... ;)
Jim
4/2/2024 - More Magazine Coverage
Here's an article I wrote for the 2007 issue of Diesel World magazine (involving Lil Red), which wraps up a discussion we were having at the time about Duramax Diesel performance - performance that didn't require tons of money, was relatively easy to do and didn't involve a lot of modification. The actual dyno performance data is included here too.
https://www.thedieselpageforums.com/...2&d=1712087851
https://www.thedieselpageforums.com/...1&d=1712087851
https://www.thedieselpageforums.com/...0&d=1712087851
https://www.thedieselpageforums.com/...9&d=1712087851
https://www.thedieselpageforums.com/...3&d=1712089600
Let me know if you have any questions.
Jim Bigley
4/16/2024 Update - An Early Track Day
Early in Lil Red's history we visited a number of tracks here in the Northwest, from Salt Lake to Abbotsford, BC. The following photo was taken at the Spokane Raceway in (I think) mid summer 2005. That day was more of a shake-down, experimenting with different products as well as trying to find the best way to launch the truck (2WD, 4WD, powerbrake light/hard...). 2WD didn't work well at all... And, I didn't have nitrous on it then. This early period was still pre EFI-Live, and the truck was still running with the original Allison, so the day turned out to be more about learning how to run the truck rather than make any real progress in performance. However, it was still a super fun day and I was able to see how well the truck/Duramax performed when closer to stock power. Plus, I got to spend time with my son and talk to other enthusiasts at the track.
https://www.thedieselpageforums.com/...6&d=1713309128
Update - Rear Disc Brakes
https://www.thedieselpageforums.com/...6&d=1713900522
Rear Disc Brake Conversion
-
for GM's 9-1/2" 14-bolt Semi-Float Rear Axle
Part I - From the archive - an in-depth look at the rear disc brake conversion used in Lil Red
The new GM 9-½" semi-float rear axle has been installed, and to improve braking ability, we've decided to upgrade to disc brakes. Rear discs help with two important areas - the reduce un-sprung weight and they increase stopping ability. Demands on the braking system increase as vehicle speeds increase. Stopping can be more important than going fast.
All of the brake components used in this conversion are factory GM 1999-2003 model-year K1500 parts bought from either a local GMC dealer or from Spalding Auto Parts in Spokane, WA. The only special items not available from GM are the adapters needed to adapt the original axle flanges to the new disc brake backing plates.
The above photo shows a complete set of parts for one side - rotors, assembled backing plate, caliper, caliper mounting bracket, flex hose and related hardware. Not shown is the backing plate adapter and related bolts. We hope to have the newly fabricated flange adapters ready for part II of this article.
https://www.thedieselpageforums.com/...5&d=1713900522
The factory cast-iron vented rotors shown here are about $60 each and are designated for a "Pickup JC5/JH5 - Vacuum" braking system, having a nominal diameter of 325-mm x 20-mm thick (12.8 x .787"). Inside each rotor is a parking brake mini-drum.
Note: You may need to reduce the outside diameter of the axle wheel flange to allow the axle flange to fit flush within the inside face of the rotor. I used an angle grinder with the truck's engine idling in drive. Both rear wheels/tires were off the truck, and the rear axle was supported by a pair of jack stands. I used an 8x16" concrete block to steady the angle grinder - to get a near perfect reduction in outside diameter of the axle flange. It only needed a very small amount of reduction.
https://www.thedieselpageforums.com/...2&d=1713900522
The disc brake backing plate assembly (pn-15206075) came as a fully assembled piece, with the parking brake components already installed. The parking brake shoe is a one-piece affair, with cable actuated and adjustable shoe engagement, to compensate for fit and wear over time.
https://www.thedieselpageforums.com/...3&d=1713900522
The above shows the rough working drawing used to fabricate the axle flange adapters. The dimensions shown here will exactly center the brake caliper over the brake rotor.
The square plates for each adapter are the same size, but are clocked differently to correctly locate the brake calipers at the front - when viewing both left and right sides. The points of the square end-plate that bolts to each disc brake backing plate are positioned at 12 & 6 o'clock. The square end that bolts to the existing axle flange (welded to the axle housing) should be positioned 5° nose down for both the right and left side of the truck. This means that the adapters for both the right and left sides of the axle are different from one another.
See Part II below...
Jim
Rear Disc Brake Upgrade - Part II
https://www.thedieselpageforums.com/...2&d=1713901757
Disc Brake Upgrade - Part II
A rear disc conversion generally offers better braking ability - both when dry and especially when wet, weighs less than most drum brakes, sheds heat faster - more fade resistant, and discs just look way cooler... Our rear disc brake installation is now complete. Read on to find out how they look and stop.
Note: I spray painted the outward facing areas of both rotors (except for the rotor surfaces that make contact with the brake pads) using a high-temp silver automotive paint. The rotors are made using a rust-able cast iron. The silver paint keeps things looking good.
We converted to rear disc brakes primarily because we had upgraded to a stronger rear axle, were using a larger tire/wheel combination, and we needed better rear braking than was provided by the original rear drums. The sum of the new rear disc brake components provided no weight savings when compared to the small 10" drums used on the original 10-bolt rear axle, but in addition to the coolness factor, the rear braking ability has definitely improved - more about that later.
There are a number of companies that offer disc brake conversion kits for 1500/2500/3500 series GM pickup trucks and SUV's currently equipped with rear drums (see list at end of article). A DIY project like this, when using all new GM parts + fabrication, will cost about the same as a commercial kit. I chose to use all new OEM parts for ease of maintenance and when buying future replacement parts. Plus, a functional and effective emergency brake was necessary because this truck will be trailered occasionally. The e-brakes included with most aftermarket disc brake kits I've seen don't inspire a lot of confidence.
https://www.thedieselpageforums.com/...7&d=1713901757
Fabricating the offset brackets was the most time consuming portion of the project. I had a local fab shop build these for me, using a drawing I supplied. The ½" steel end plates were cut from sheet using a water jet CNC, and a section of steel pipe was located that fit the OD of the axle tubing.
Once back from the fab shop, I spent some time drilling and tapping the sixteen holes for the 12mm bolts, then squirted on a little black paint.
It should be noted that the dimensions listed on the drawing fit the 1997 model-year 9-½" 14-bolt semi-float axle used in our buildup. If you are installing similar disc brake components on the smaller GM 10-bolt rear axle, you may need to adjust the thickness of the offset brackets to compensate for a different axle flange location. Flange offset bracket thickness is correct when the rotors are centered in the assembled disc brake pad brackets.
https://www.thedieselpageforums.com/...8&d=1713901757
The newly fabricated offset bracket has been bolted onto the axle flange using four 12mm bolts, each torqued to 100 ft/lbs using thread locker. Correctly clocking the square ends was important to transfer the correct orientation to the disc brake backing plate.
I drilled out the threaded holes in the original axle flange (using a ½" bit) to allow the 12mm bolts to pass through and then thread into the new brackets.
This bolt-on installation has proven to be plenty secure. A lot depends on the quality of the welds. I had a pro do the welding for me.
https://www.thedieselpageforums.com/...9&d=1713901757
The disc brake backing plate has been bolted on using four 12mm bolts, each torqued to 100 ft/lbs using thread locker. The calipers and disc pad brackets are bolted onto the forward-facing side of the backing plate, 9 o'clock on the driver's side and 3 o'clock on the passenger side (passenger side shown).
The axle shafts need to be removed when installing the offset brackets and disc brake backing plates. It's a fairly simple job to remove the differential carrier pin, slide the axle toward the center, then remove the axle-retaining C-clip. The axle will then slide out. Be a little careful not to damage the wheel bearing seal.
https://www.thedieselpageforums.com/...1&d=1713901757
The original steel hydraulic brake lines were carefully reshaped by hand to fit the disc brake flex-line mounts. The truck's original e-brake cables can't be modified to work with these GM disc brakes due to the new rear facing e-brake cable anchor (1) and actuation lever (2).
https://www.thedieselpageforums.com/...5&d=1713901903
To match the new disc brakes, you'll need a set of e-brake cables made for a similar wheelbase 1500 series truck (i.e. 2000 model-year, models 03, 06, 53 - new style 4x4). These loop over/under the axle, then sweep around to make the connection on each side.
The above driver's side photo shows the e-brake cable sweeping around and anchoring to the shock mount, then running under the axle tube, before sweeping up and through the wire loop bolted to the frame.
https://www.thedieselpageforums.com/...4&d=1713901903
On the passenger side, the e-brake attaches to the rear facing side of the brake backing plate, loops away and then is anchored to the axle tube, before sweeping up and over the pumpkin. The cable mount shown in this photo that secures the cable to the axle tube is simply a steel strap, but you can weld on a tab if you have access to the right fabrication equipment.
A metal clamp secures the e-brake cable from one bolt on the differential cover. From there, the cables sweep across and forward through the wire loop on the frame.
https://www.thedieselpageforums.com/...3&d=1713901903
The forward ends of both e-brake cables mount to a fabricated bracket that is bolted to the frame. I may tinker with it a bit over the next few months.
A 2" long piece of ½" square steel tubing was used to provide an anchor point for both cables that can rotate slightly to accommodate a slight misadjustment between the right & left e-brake shoes. This is similar to how the factory parts operate.
Articles have appeared in various truck magazines that mentioned a few potential complications when converting from drums to discs. First, some recommend a new brake master cylinder designed for a 4-wheel disc system, to either provide more fluid volume for the larger rear disc brake caliper pistons or to modify hydraulic brake pressure. Secondarily, they mention that the front/rear brake proportioning valve may need to be modified or replaced for some installations. I had installed a new brake master cylinder and hydraulic brake booster when the truck was assembled a year ago, and I did not want to buy replacements. After breaking-in the rear rotors/pads and performing a few hard stops, I feel that (for this particular truck and installation) a new master cylinder is not necessary, nor is replacing/modifying the proportioning valve. The current front/rear brake proportioning appears to be nearly ideal for this lightweight truck.
I lucked out, but some of the factors that contribute to correct brake proportioning include the weight of the vehicle - especially over the rear, condition of the brake master cylinder and hydraulic brake booster, wheel & tire combination and type/composition of the disc brake pads themselves (some are more aggressive than others). I installed the NAPA Premium Disc Brake Pads #AE-7662-M, which are asbestos-free and are supplied with new anti-rattle clips.
An alternative to retrofitting discs to your existing rear axle would be to locate a suitable disc brake equipped rear axle that had been installed in a newer vehicle. If you can locate a replacement disc brake equipped rear axle in good shape and with the correct gearing, your total cost could be somewhere in the same general price range as a rear disc brake conversion kit. I considered going that route, but unfortunately, GM didn't produce a six-lug disc brake equipped rear axle with the 9-½" ring & pinion that I needed (all current GM disc brake equipped 9-½" rear axles now have 8-lugs, and are used on GM's light-duty ¾-ton trucks).
If you have a drum brake equipped heavy-duty ¾-ton or 1-ton truck, you'll find a variety of aftermarket disc brake upgrade kits currently available for your rear axle. In addition to the braking advantage, disc brakes would provide a worthwhile weight savings due to the much larger drums used on the HD vehicles. Incidentally, if you maintained the functionality of the RWAL (Rear Wheel Anti-Lock) braking system for your conversion, this disc brake conversion won't affect the performance of the anti-lock system. This is because the RWAL uses the vehicle speed sensor to determine whether the rear wheels are rotating during a hard brake application. There are no individual rear wheel speed sensors used by the truck's original braking system.
Would I do it again on a ½-ton? Tough call, but I would if there was a need for improved braking performance or simply wanted more modern disc brakes on the rear axle. Appearance is important too... They do look cool, and the upgrade looks factory! TDP
Continued next post...
Update 4-30-2024 - Bling! New Tail Light Lenses
It's been a long time since I polished the original tail light lenses on Lil Red. After polishing them the first time, they photographed well enough for the promotional photos I needed. They weren't perfect, but they were good enough, considering how much other stuff still needed to be done on the truck during that time. But that was then, and this is now - and the tail light lenses needed attention once again (see below). So.... instead of polishing them this time around, I thought I'd take the easy way out and just replace them.
https://www.thedieselpageforums.com/...8&d=1714494527
Yes, I could have polished the original lenses shown here on the left... yet again. I have the polish and the buffer, but the foam rubber gaskets that seal the lenses against the truck have deteriorated somewhat, and the foam perimeter gaskets are porous enough to hold grime and/or wax, which makes them tough to keep clean.
Visually, one of the things I tend to notice about new vehicles is the shiny "jewel-like" faceted appearance of head/tail light lenses. New lenses just look... well... "new". Spiffy lenses improve the look of any truck.
https://www.thedieselpageforums.com/...7&d=1714494527
I've used this "Eagle Eyes" brand of lenses before - I have a set of headlight/park lenses on the shelf for my 2001 GMC. The quality is pretty good. The new tail light lenses shown here were made in Taiwan and are priced reasonably via Amazon Prime... a little over $50/pair delivered. Being the hoarder that I am, I'll likely hang onto the original lenses for a while longer. ;)
Jim
Update 5/22/2024 - Lil Red's Duramax Conversion - Intercooler Details
https://www.thedieselpageforums.com/...1&d=1716398605
From the 2004 archive: These photos show the installation of a modified stock 1994-2002 Dodge intercooler - to give you some idea what the installation looks like in Lil Red. This Project Update will introduce you to the intercooler installation process, and illustrate some of the modifications necessary to install a 1994-2002 Dodge Cummins intercooler in a 1988-98 C/K pickup truck or Suburban.
As it turns out, the Dodge Cummins intercooler core dimensions are exactly the same as the core used in a stock 2001-2004 GM Duramax powered 2500HD/3500 truck. At the time I put Lil Red together, I could not locate a used/salvaged GM intercooler, and was already over-budget on this project, so I wanted to cut costs where I could. A factory new GM intercooler was more than $600 at that time. So, the only reason I bought and modified a Dodge Cummins intercooler was because I was able to buy one on eBay for a lot less. A GM factory Duramax intercooler would have been my first choice otherwise, even though it too might need to be modified.
https://www.thedieselpageforums.com/...2&d=1716398605
The above photo shows what the modified Dodge intercooler looks like installed on the truck, but before the hood latch support had been modified.
This intercooler was purchased from a seller on Ebay. I had been watching Dodge intercooler auctions for a few weeks, before deciding to actively engage in the buying process. Some of the offered intercoolers were removed from wrecked or damaged Dodge trucks, so you need to evaluate any intercooler offered to determine whether it remains usable or whether the damage was more cosmetic in nature. The one I bought did have some cosmetic issues, but was structurally sound and leak-free. Based on the auctions I monitored, you might expect to pay anywhere between $150 and $400 depending on condition for a usable Dodge Cummins intercooler and the whims of your bidding competitors.
The Dodge IC core is approximately 15-3/8" tall, a couple of inches shorter than the available space in front of the radiator.
The IC core is a little more than 2" thick, and will fit fairly well behind the hood latch support bracket in the space formerly occupied by the A/C condenser. The hood latch bracket must be modified to allow for a modified A/C condenser to fit ahead of the intercooler. I could show the A/C condenser mods in a future update if anyone would like to see how I solved that problem. Can't live without A/C... ;)
Aside from being 15-3/8" tall, the core is also 36" wide, not counting the bulk of the end tanks. A 36" wide core closely matches the radiator core width, and works well with the C/K OBS (Old Body Style) radiator core support. The total width, including the end tanks wound up being about 45-½".
These photos show the mods I made to the aluminum end-tanks of the intercooler. As received, the Dodge intercooler's 3" inlet/outlet would need to penetrate the box-sectioned structural member on each side of the radiator core support. I decided not to weaken the radiator core support, which meant modifying the intercooler - i.e. moving the intercooler's inlet/outlet to be outside of the radiator core structural supports.
Widening the intercooler end-tanks required adding material - I used 1/8" aluminum sheet material.
Jim
5/23/2024 - Intercooler Details #2
https://www.thedieselpageforums.com/...6&d=1716488941
This image shows more detail about how the intercooler end-tanks were modified. The intercooler's inlet and outlet were moved outward to clear the boxed steel sections of the radiator core support, and then the end-tanks were modified to help provide more clearance for the head/park lamp assemblies. A 4" hole needs to be cut in the radiator core support where the intercooler's inlet/outlet pass through.
I made all of the cuts/mods to the original intercooler, then took it and the various pieces to a metal shop for aluminum TIG welding. If doing this again I'd buy my own TIG welder and learn how to use it. In the end there would be no labor charges and I'd still have the TIG welder... all for about the same final cost. And incidentally, once all of the mods were completed I flushed water through the intercooler in each direction several times in an effort to remove any debris that might have collected internally during the process of modification. ;)
I used the GM factory intercooler hoses, clamps and aluminum tubing produced for a 2001 model year Chevy/GMC equipped with a Duramax 6600. If you have a donor vehicle that'll provide all this, you're golden. You don't have to use the original factory parts, but they will make it just a bit easier. The factory aluminum intercooler tubing will need to be extended because of the widening of the intercooler inlet/outlets. This is a relatively easy process. I used 3" aluminum agricultural sprinkler pipe to provide the extension material. I still have about ~8' of this pipe laying around... if anyone needs some. The Conversion Guide shows how/where to add the extensions.
Of course, there are alternatives with regard to intercoolers. You could search for a generic intercooler core from an online source that suits your installation, then modify it as/if required. We did that very thing for a 6.5L diesel Suburban in a book published by The Diesel Page a few years ago... see link. At the time, the total cost, which included the core, all of the hoses, clamps and aluminum tubing cost about $400 total. So, you don't have to begin with a Dodge or GM intercooler. A generic intercooler core just needs to be sized for a diesel engine approximating the displacement of the Duramax, and of course fit into the available space.
In addition, I know of at least one Duramax conversion running without an intercooler. An owner in Canada used our mounts and Conversion Guide, but chose to avoid the installation of an intercooler because his use for the truck would be mostly light-duty. Personally, I'd still want an intercooler because of the ~20-psi boost pressures and the heat load that creates, but the installation in that Canadian truck shows that a conversion can work without an intercooler in certain light-duty situations. It should be noted that running without an intercooler while towing heavy could produce dangerously high EGTs that put the engine at greater risk. Plus... the engine control module (ECM) monitors intake air temperature, in part to help protect the engine. Excessively high intake air temperatures will cause the vehicle's ECM to defuel the engine - reducing power. It's worth the trouble to install an intercooler, even if you don't plan to use the truck to tow.
How is the intercooler mounted?... you might ask... The intercooler shown here is setting on 2 inch wide 3/16" thick rubber strips that had been glued onto the radiator core support using silicone caulking - to the horizontal and vertical surfaces where the intercooler core made contact. You can see small portions of the strips I'm talking about in the above image. The modified hood latch assembly then clamps the intercooler to the radiator core support - using rubber strips as cushioning. It's been a successful and solid mounting strategy for a long time... although, if my truck were driven on lots of rough road/off highway use, I'd consider welding some beefy 1/4" thick aluminum mounting tabs onto the intercooler core end-tanks that allow bolting it to the radiator core support using rubber-isolated hardware - along with the rubber cushioning strips mentioned here.
There are always different ways to "skin a cat". You may have a different way of completing one of these projects. If nothing else, what's shown here is simply one way, albeit a successful way, that describes how I installed an intercooler in my truck. Project philosophy here in TDP always includes performance, reliability, cost, reproducibility and of course appearance - all important factors.
Beyond the intercooler - there is another related conversion hurdle I faced soon after completing the intercooler installation, and I may show that solution here in a future update... the A/C condenser installation. I'm really happy with the modified A/C condenser I installed - it's solid, reliable, works great and looks professional. After the initial installation of the A/C system and R-134A charge, it's not needed any attention in the years since. Let me know if you'd like to see more. --- Jim
https://www.thedieselpage.com/duramax/1998LBZ09c.jpg
On edit: The above image appeared in a article produced by The Diesel Page a while back, showing Blake Twiehaus's 1998 Chevy K1500 LBZ conversion. Blake used a Dodge Cummins intercooler like I did, but he chose not to widen the inlet/outlet. Instead, he modified the boxed sections of the radiator core support to accept the narrower-original width of the intercooler's inlet/outlet, while maintaining the radiator core support's structural integrity. Your can read more about Blake's conversion here: https://www.thedieselpage.com/duramax/1998LBZ.htm
Did this forum thread or YouTube video help you with your conversion/swap? Would you like to share this information with others or help us get the word out about Duramax swaps? It's easy! Simply link to us in your own YouTube video, or post the link(s) shown here in a forum post, email message or social media site. Thank you!
www.thedieselpageforums.com/tdpforum/showthread.php?35210
https://youtu.be/--9bY1T3XoQ
Thank you!
Update: 6-12-2024 - A/C Condenser Details - Got to be Cool!
Lil Red had been on the road and drive-able for about 12 months by the time the following photos were taken. This means I had driven it through the previous summer (and The 2004 Diesel Page Rendezvous) without air conditioning. It was seriously hot that summer, and I knew that Lil Red simply had to have air conditioning going forward! One summer was enough to tell me I didn't want a repeat.
By the time the truck became drive-able the year before, I had a pretty good idea how I would complete the A/C installation - I just needed to move through the process of modification/installation. And, I could lean on a friend and automotive A/C expert from Tampa, Florida (Gordon Marks) who answered all of my questions and even loaned me some of his hose making tools and supplies during this process.
https://www.thedieselpageforums.com/...0&d=1718213424
The above image shows the newly modified hood latch bracket, made to accommodate the added space required by the intercooler and A/C condenser. It was all TIG welded together. Most of the individual metal pieces used here for the hood latch bracket mod/extension were made from rectangular steel tubing.
The long section of rectangular steel tubing was notched to allow it to extend 3-4" up the back side of the hood latch portion - to provide additional structural rigidity. The bottom of the new hood latch bracket (that bolts to the bottom of the radiator core support) includes a flat steel pad large enough (about 3" wide x 3" tall x 1/8" thick) to clamp the bottom part of intercooler to the radiator core support when bolted on. The upper portion of the modified hood latch bracket is likewise used to clamp the top of the intercooler against the top of the radiator core support. A 1/8" thick rubber strip was used wherever the modified hood latch bracket assembly made contact with the intercooler.
Note: Moving the long section of the hood latch bracket a couple of inches farther forward meant the lower/center attachment mount for the grille will also need to be shortened by the same amount. In Lil Red I simply measured how much to remove, cut the plastic grille mount by that amount, then pop-riveted a 1/16" thick aluminum 90-degree angle onto the shortened plastic grille mount to accommodate the new dimension. Then, I drilled a new hole into the rectangular steel tubing on the modified hood latch assembly (with nylon insert, like OEM) to attach the shortened grille mount. Easy...
--------I'm not using an air/ATF cooler - just the cooler inside the radiator. This lightweight truck doesn't need the additional cooling... plus the Allison has a deep-finned pan. On a hot day, the Allison runs at engine temperature around town, but drops some on the highway. If your truck will be used to tow, I'd install a factory ATF cooler in the upper area just to the right of (passenger side of) the hood latch mechanism. There should be enough room there. You'll have to fab some bracketry, but that should be easy for you at this point. Or... you could put a different shaped aftermarket ATF cooler in the area behind the holes in the bumper... Likewise with the smaller power steering cooler.
I bought a brand new factory GM A/C condenser for this project - made for the model year of Lil Red, then modified it to fit. It wasn't that expensive... surprised me.
Incidentally... The new condenser arrived without any paint on it... just raw aluminum. I initially wanted to spray on a nice layer of satin black paint, but in the end I just dusted on a thin layer to make it less visible through the grille. Paint can act as a thermal barrier, and I didn't want to hamper the condenser's ability to reject heat. So, if the paint looks a little thin here, that's why. The steel brackets, on the other hand were removed and properly painted before final assembly. I also used thread locker on the sheet metal screws used to fasten the new brackets to the ends of the condenser.
The 3-axis position of the actual hood latch components couldn't be changed (hood latch, safety catch). The intercooler installation forced the condenser location to be father forward than the original had been. Mounting the condenser farther forward meant the condenser couldn't be as tall as the original. Shortening the condenser required removing the top 4 aluminum cross tubes along with the cooling fins that covered them. What's described here is the best way I discovered to modify the A/C condenser.
Once I knew how I was going to mount the condenser and knew what mods were necessary, I used a 1/16" thick 4" diameter cut-off wheel on an angle grinder to carefully slice through the delicate fins just beneath the 4th cross tube. This worked well, but go slow, the aluminum cross tubes are thin walled and easily damaged. The remaining stub ends of the cross tubes on the far right side (passenger side) of the condenser were left long enough to allow the stub ends to be rolled over and crimped, followed by aluminum solder/welding. The stub ends that you need to solder/weld closed should be left long enough to account for a flub or two (i.e. the need to re-cut square, fold over, crimp and re-weld). The tubing is pretty thin-walled and delicate. I used a propane torch for this, and I practiced for quite a while on the excess tubing that had been removed earlier. You can buy the torch and flux-core aluminum welding rod at Harbor Freight.
Removing most of the top 4 cross tubes and their fins to allow the condenser to fit, and then soldering/welding the ends of the tubes closed was the most tedious part of this. Honestly, I didn't know if this sort of modification would work when I began the condenser installation. But, in the end I didn't mess up the new condenser, and it installed nicely. Practicing your aluminum soldering/welding on the leftover condenser tubing you removed is essential... dare I say required. It took me a while to learn how to do it without melting the tubing.
https://www.thedieselpageforums.com/...8&d=1718213424
The above shows one of the bottom corners of the condenser, and how I made a bracket mount. The bracket is made from 1/16" x 1" wide steel strips bought from a local Ace Hardware store. The mounting bolt hole I used here, at the bottom of the new bracket (sorta behind the wiring loom), was one of the mounting locations for the original condenser. The right/left sides of the new condenser are mounted tight up against the intercooler, so I used a layer of dense double-sided foam tape to separate and cushion the sides of the condenser where each rested against the intercooler. You can sorta see the white strips talked about in these photos. The dense double-sided foam tape I used came from a friend of TheDieselPage.com who owns a local auto body shop - though I only peeled the backing off one side (didn't want it to stick to the intercooler). The tape is made to attach emblems and trim onto cars... I imagine this tape can be sourced through retail outlets that sell auto paint and body supplies.
https://www.thedieselpageforums.com/...9&d=1718213424
The upper mounts were constructed as shown above - similar to the bottom mounts. The top most mounting bolt (behind the yellow arrow) was one of the bolt hole mounting locations used by the truck's original A/C condenser. In fact, all four corners of the condenser used the original mounting bolt location.
As mentioned earlier, the A/C system has worked very well since the initial installation/R-134a charge in 2005. It's not needed a recharge, a top off or any other service. In addition to installing a brand new condenser, I also installed a brand new accumulator that mounts onto the firewall, in part because I was converting the original refrigerant used in this truck from R12 to R-134a - I wanted make sure there wasn't any debris or non-compatible compressor oil left in the system. Even on +100 degree days, the system can easily maintain comfort inside the cab.
Because I was adapting a new style A/C compressor to an earlier truck, I needed to make a couple of hose assemblies. This was accomplished by using some new hose lengths and appropriate fittings, assembled using an A/C hose crimping tool. All of these items can be acquired online for not a lot, and Youtube will show you how to use them. Not hard! Contact me via email if you need additional tips.
In the end, the cool factor arrived just in time!
Jim
Update: July 9, 2024 - Best Duramax Swapped OBS Chevy K1500?
https://youtu.be/8KaAONkAUCY
A bit hyperbolic perhaps, but this new video asks the question... "Is this the best Duramax Swapped OBS Chevy K1500?" Included here in this video is some basic performance discussion, and you'll learn more about what Lil Red used for performance products when the truck was at the track...
You can help our video channel to grow and reach more people! Please subscribe to our YouTube channel - run your mouse cursor over the little circle truck image in the upper left of the video shown here to see the subscribe button.
I recommend that you create a YouTube account, if you don't already have one. It's easy and free to register at YouTube.com, plus you'll be eligible for free stuff here in The Diesel Page before long. Before long we'll begin offering all member-only online content here at TDP free of charge to those who are subscribed to our YouTube channel. Your YouTube account name will be linked to the free access list. Just send me your YouTube user name using the "Contact Me" link in my signature below to gain access.
TDP's long-term goal is to produce more free content videos. Some of these videos will be derived from the several books we've published. The first book to be transformed into a video series will be the "Duramax Service Guide". This book is, in my opinion, the most valuable book we offer.
Where are we are currently in the Service Guide series? The first two videos in the series have already been published and are now available as videos - an Introduction to the Tools, Supplies and Procedures that are necessary to begin a project like Duramax 6600 LB7 injector replacement, head gasket replacement (coming soon), water pump replacement and more... We hope you'll like them!
The 6.5L Diesel won't be left out. More about the 6.5L Turbo Diesel Blazer as well as segments from the 6.5L books will be featured in video format as often as schedules allow.
Subscribing will ensure you don't miss any new videos. As always, your input, suggestions and advice are all important.
Thx,
Jim
9/4/2024 - More Magazine Coverage
Here's an article I wrote for the May 2006 issue of Diesel Power Magazine involving Lil Red, which details the installation of a performance ATS Allison. This transmission has been in Lil Red all this time since. There have been no codes or slips detected. - Jim
https://www.thedieselpageforums.com/...8&d=1725475926
https://www.thedieselpageforums.com/...9&d=1725475926
https://www.thedieselpageforums.com/...2&d=1725476948
https://www.thedieselpageforums.com/...1&d=1725475926
See our YouTube channel!
9-26-2024 Update - Bellhousing bolt pattern
https://www.thedieselpageforums.com/...6&d=1727369834
I used a TH400 auto transmission bolted to the LB7 during the first trial fitting sessions in Lil Red's chassis. The TH400 was lighter than the Allison and a bit smaller - easier to manage when dealing with a minor transmission tunnel clearance puzzle.
As you can see, the earlier Chevy/GMC TH400 transmission bellhousing bolt-pattern is the same as the Allison, and (though not shown) the bolt pattern for the TH400/4L80-E torque converter is the same too.
Jim
Update 11-4-2024 - More Swap History & Bellhousing Design Compatibility
The bellhousing design allowed GM to utilize the Duramax in the van application with the 4L80-E automatic transmission (250-hp/440 lb-ft). And, then there's this...
https://www.thedieselpageforums.com/...0&d=1730746086
GM Powertrain's 2000/2001 Pikes Peak C1500 race truck (GMT-800 body style) was also equipped with an LB7 Duramax and a special 4L80-E automatic transmission that had been carefully assembled by GM Powertrain. That race-prepped Duramax 6600 engine had been hand assembled by Isuzu engineers in Japan, and was producing more than 600-hp, or so I was told.
By the way... I came to within a whisker of getting that Pikes Peak GMC from GM Powertrain. The promotional program that that truck was built for was complete by early 2002. In talking to the GM Powertrain promotional team at the time, we began to explore the possibility of The Diesel Page acquiring the truck, and then continue with promotion. Initially, the deal was approved, and I began preparing for the trip to Michigan to get the truck... Unfortunately, the deal fell through. I never did hear what happened to the Pikes Peak truck after that. :(
That's me in the red shirt standing alongside the truck - at the DMAX engine production facility in Moraine Ohio. In the background you can see a banner given to TheDieselPage.com by DMAX, GM Powertrain and Allison during our 2001 Rendezvous.
https://www.thedieselpageforums.com/...0&d=1732050388
Another shot of our visiting DMAX in Moraine Ohio.
Jim
Update: 2/28/2025 - L5P Duramax Swap Mounts?
L5P Duramax Swap Mounts
A question came up recently about whether the swap mounts we offer will fit the newest version of Duramax 6600 - the L5P. Our mounts were designed for the LB7, LLY, LBZ, LML and LMM (2001 up to the 2016 model year engines - essentially all but the L5P which first appeared in the 2017 model year GM trucks). All pre-L5P engines utilize the same engine mounting dimensions and bolt patterns. The L5P block casting, on the other hand, was redesigned to include a new engine mount design and bolt pattern, and the L5P incorporates a completely different oil pan (which may actually be a better fit for the GMT-400). We're working on offering an updated mount design for the L5P/GMT-400 swap (for the 1988-1998 body style), and I hope to have swap mounts for the L5P available later this spring.
In addition, we've seen that through the years, GM Powertrain has added more and more emissions-related components to the top of the engine. The L5P is the pinnacle of that trend. To maintain adequate hood clearance in a GMT-400 body style truck, installing an L5P would require a cowl induction hood and/or a 2" or so body lift. I'll have more information on all this as soon as I get my hands on an L5P. In the meantime... Click HERE to read more about our current mounts or to place an order.
Jim
Update 4/2/2025 More Intercooler Details
Here's a photo that was shot during the fitting/modification process for getting a Dodge Cummins intercooler to work for this Lil Red project - and get it all to fit behind the grille.
https://www.thedieselpageforums.com/...5&d=1743612717
My reasoning for widening the inlet/outlet was to position the required-new hole through the radiator core support to just outside the boxed-steel section(s) of the core support. This helped to maintain the structural integrity of the core support and maintain access to the core support frame mounting bolts. The downside though is that the widened inlet/outlet required modifying the park/turn light housings. This also required modifying the aluminum tubing used to connect the intercooler to the engine. In my case, I used 3" aluminum agricultural sprinkler pipe as the stock to extend the factory OE piping.
If doing it all again, I might investigate using an aftermarket intercooler core sized for the existing real estate behind the grille while doing my best to maintain the engine's flow requirements and park/turn light assembly clearance. - Jim
By the way, this modification to the intercooler (on both sides) cost $500 at a metal fab shop, and that was on top of the $200 cost of the salvage eBay Dodge intercooler. A new factory Duramax intercooler at the time was $600 through our local dealership. Decisions... decisions... ;)
Update 5/5/2025 - OBS/Duramax Swap Radiator Choice
I've been asked recently about the radiator I'm using in Lil Red... I installed a brand new 2001 model year radiator originally produced for a Duramax/Allison powered 2500HD/3500 GM pickup truck. This update describes how that new radiator was installed, and will answer the questions I've received about it. This is an easy topic! By the way, these pics were taken in May 2025.
I chose to go this route after I measured the radiator in my 2001 GMC 2500HD Duramax powered pickup. That 2001 model year Duramax radiator was the exact same dimension (core height, width & thickness) as the radiator found in a 1994-1998 6.5L diesel powered OBS (Old Body Style - GMT-400) pickup. With just a simple mod (removal of a mounting lug), the new radiator was a direct bolt-in - using 1994-1998 factory OBS rubber mounts, brackets and the 1994-1998 OBS 6.5L diesel fan shroud. Perfect!
https://www.thedieselpageforums.com/...6&d=1746468170
You can see here that the 1994-1998 6.5L diesel fan shroud takes a step up in height of about 2" from the top of the core support. Lil Red originally came with a gas 350, so it had a shorter, thinner and narrower radiator and smaller fan shroud (though the truck's radiator core support was essentially the same as that used with the 6.5L diesel). With minor mods (removed a couple of knock-out panels to match the width of the new radiator core), Lil Red's original radiator core support allowed for a direct bolt-in of the larger Duramax (or 6.5L diesel) radiator and the OBS factory 6.5L diesel fan shroud - both (core support and fan shroud) fit the 2001 Duramax radiator perfectly... :)
https://www.thedieselpageforums.com/...4&d=1746468170
The arrow in this photo points to what remains of a rubber isolated mount that was part of the Duramax radiator. I simply cut that mount off. Then, the Duramax radiator was slid into the core support and held by the same factory rubber mounting system used for a 6.5L diesel radiator.
https://www.thedieselpageforums.com/...5&d=1746468170
I installed a 2001 model year factory 9-blade composite fan made for the Duramax. However, because the opening in the 6.5L diesel fan shroud was designed for a 19" fan and because in my swap the center of the fan sits about 3/4" above the center of the fan shroud opening, I reduced the diameter of the Duramax's 21" 9-blade composite fan down to a diameter of 19" (1" off every blade).
The fan trimming was super easy. I simply made a pattern using card stock that maintained the fan tip profile, but reduced the length of each blade by exactly 1" using a Dremel cut-off wheel and sanding disc. I was careful, took my time, and the end result was nearly perfect. The blade tips are very lightweight, so there wasn't a concern about a loss in balance over the 9 blades - if you do your best to make each blade tip the same. The modified 19" diameter fan shown here still moves a lot of air. But, if this were an 2500/3500 Duramax powered truck, I may have considered trimming the fan shroud to help maintain the full-diameter fan.
I will say that I continue to be super impressed with the factory OBS 1994-1998 6.5L diesel fan shroud. The shroud looks great and is very well made. Even when bought over the counter at our local GM dealer's parts counter, it was a super good deal... The plastic is thick enough to prevent any sort of distortion from typical use (i.e. leaning on it), and it looks great too.
Swapped trucks using the Allison can't incorporate a factory OBS 6.5L diesel radiator only because the internal radiator ATF cooler and fittings are too small to work with the Allison. If your swap incorporates a ZF-6 speed (or other) manual transmission, I don't see why you couldn't use a factory OBS 6.5L diesel radiator. Both radiators use the same materials (aluminum core with plastic end tanks), same height/width/thickness/inlet/outlet and even appearance. I contend that GM Powertrain began with their 6.5L diesel radiator when developing the cooling system for the Duramax.
And incidentally, I swapped out Lil Red's original vacuum-assisted brake booster and brake master cylinder for a hydraulic brake booster and matching brake master cylinder made for the OBS 6.5L diesel equipped trucks. Yes, the master cylinders are different, depending on whether it's a vacuum-assisted or hydraulic-assisted application. The diesel (hydraulic) brake parts were a direct bolt-in swap. Once that was completed I simply connected the 2001 factory power steering pump produced for a Duramax to the hydraulic brake booster and steering box. The package works as expected. And, I later learned that the OBS trucks equipped with a big-block gas engine will already have the hydraulic brake booster and matching brake master cylinder.
I did not install the auxiliary ATF air/oil transmission cooler normally used in a Duramax/Allison powered pickup truck. Nor did I install a power-steering fluid cooler. If this truck was being used for towing I would have installed both coolers. But, this is a lightweight truck that doesn't stress those systems. Normal summertime transmission temperatures run near or somewhat below engine temps. For example, today with ambient temps approximately 80 degrees F, and after driving the truck for about 30 miles, the engine temp measured 188.4 degrees F and the Allison ATF measured 181.3 degrees F with a scan tool. There hasn't been much of any degradation (smell/color change) of the transmission fluid or PS fluid, so ATF/PS fluid temps must not be out of hand. But, I may add those coolers to those systems someday just out of curiosity.
Those who have built project vehicles know that their car/truck is usually never 100% complete - seems there is always something new to add or complete, or something that needs to be updated/modified/improved. After driving Lil Red for 21 years, I have a lot of hindsight to pass along here in this forum thread... :) Hmmmm... Besides driving it more, what would I do differently if starting over?...
Let know if you have any more questions.
Jim
6/17/2025 Update, Swap Questions
On 2025-06-16 13:11, William D wrote:
> Jim,
> I just recently received the conversion guide in the mail over the
> weekend and have enjoyed reading through all the information listed
> in your Silverado conversion however I am still on the fence as to
> which way to go ( I've got time ) . While I was waiting for my book to
> arrive I have been scanning through the members pages and found the
> "Swapping engines " link in the reference section. I know that I'm
> going to remove the 7.4 big block rat motor but which way to convert
> to diesel is still up for debate for me. I was under the impression
> that the 6.5 Detroit was a boat anchor and should be avoided at all
> costs but the more I dive into the subject the more I'm finding that
> the biggest issues were more caused by Chevrolet engineers rather than
> Detroit and that all of these issues are easily remedied. I'm looking
> for the most straightforward conversion possible without breaking my
> back as I'm 7-8 years away from retirement. I've already dumped a load
> of cash into the drive train of my K2500 and still have a lot of
> upgrades to install so I'm likely not going to sell this rig to look
> for another project truck and I have no interest in financing a new
> diesel rig so I'm very much interested in doing a diesel swap into
> this rig whether it be a 6.5 or 6.6.
>
> Looking at the key points of a 6.5 swap it seems to be comparing the
> 5.7 liter characteristics to that of the 6.5 but I'm curious to know
> what or if any of these compare to the 7.4? Also my rig is equipped
> with the NV4500 manual five speed which I plan on retaining. So if I
> go with the 6.5 swap will I have to upgrade my flywheel and clutch to
> accommodate the higher torque of the Detroit motor? I'm assuming that
> the motor mounts will be the same for both motors and I'll also have
> to change wiring harnesses? Are your books on the 6.5 Detroit
> inclusive to the workings of the motor or are there any articles on
> doing this sort of swap?
---------------------------------------------------------------------------------------
Hi William,
Questions...
1- How nice is the truck? What year truck is it?
2- What is your level of expertise for auto mechanics?
3- Is this a truck you intend to keep?
4- How will you use the truck, or how would you like to use the truck? i.e. tow a big travel trailer several times a year, light towing more often than that (i.e. boat), commuter mostly, or family transportation all the time, etc.
5- The truck's current differential gearing?
6- Swap budget?
Beyond that, a nice Duramax swap will make it easier to find parts and service, and your truck will be more valuable if the swap is nicely done. The 6.5 can be made to be quite capable, but it wasn't designed for the most severe towing duty, and parts/service are becoming harder to find. You'll be the service provider.
For your specific 7.4L equipped truck, the existing radiator, fan shroud and hydraulic brake system can be maintained no matter which engine you go with.
Check out this link for a Youtube video about a 1998 Chevy/LBZ Duramax/ZF-650 swap.
https://www.youtube.com/watch?v=iDr8vhoGJ8Q
The important thing for you here is that he installed a ZF-650 6-speed manual. Some of that manual transmission info might be of interest to you, and I'm sure the truck owner would answer your questions about a manual transmission installation. Beyond that, I'm pretty sure your NV-4500 can be adapted to work, if you keep engine power reasonable. The "650" in ZF-650 is the rated torque limit. The rated torque limit for the NV-4500 is 460 lb/ft. The stock 2001 LB7 Duramax factory rated torque was 520.
I've always compared a properly built 6.5L turbo diesel to a stock 7.4L gas engine in overall performance, but with nearly twice the fuel economy. The Duramax, even with stock programming will perform above that. The Duramax fuel economy will be 11-12 while towing and 18 or a little better while traveling empty at Interstate speeds - depending.
Your gas V-8 engine mounts are the same for either the 7.4L gas or the 6.5TD. The motor mounts are different for the Duramax. The Conversion Guide shows what they look like. The flywheel/pressure plate/clutch plate are different for the 6.5 and the Duramax, when compared to the 7.4L gas.
And, visit this link to learn more about wiring for the Duramax.
https://www.thedieselpageforums.com/...133#post333133
The books we offer on the 6.5 include all of the diesel-related wiring circuits. It's really not too complicated. Your existing ECM/PCM will be pretty confused, but there are work-arounds for just about everything.
Lastly, if you go with the 6.5, you can install a mechanical fuel injection system. That simplifies the wiring to its most basic form. My recommendation would be to install the mechanical diesel fuel injection system if you decide on the 6.5.
Jim
