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I am so glad I checked the torque on the Arp studs this morning. It seems the gasket settled within just 8-10 hours that I was able to feel about 5 pounds of torque lost from the settlement of the head gasket.
Note: All final torquing needs to be done before the Optimum Black cure time expires.
Now I would like to talk A LOT about Cast Iron Rockers for the 6.2., failure points, how to correct failure points and my experience with them over the many years of running them on every 6.2 I had opened up.
Here is some info I had stored away that is useful.
“With the high compression ratio of the pre-chamber diesel, there is minimal valve-to-piston clearance. Because it is important to have a rigid valve train that insures a precise valve train motion through the speed range, a shaft supported valve rocker arm design is used. Nodular iron rocker arms with a steel backed bushing are used. The shafts are bolted to case stanchions on the cylinder head. The design has a steel backed bronze alloy bushing in the rocker arm which is final bored after being press fit into the cast arm. This bushing uses a performed circumferential oil groove and 2 cross oil grooves for directing lubrication to the mating shaft surface. Oil is supplied to the rocker arm via the hollow push rod and the arm in turn has drilled passages that provide a flow path for oil to the bushing.
The 1982 engine used a hardened steel spacer and a metric washer at the rocker shaft attachment. The 1983-84 engine uses an unhardened spacer and a steel cleat. The steel cleat has a large gap 90? to the bolt. This prevents any closure, and the cleat spreads the load”
“ROCKER ARM SHAFT INSTALLATION, 6.2L DIESEL
Rocker arm shafts may break if installed improperly. Uneven torquing causes stress at bolt holes.
The proper method to install rocker shafts is as follows:
1. Set engine balancer timing mark at TDC mark on engine.
2. Rotate engine 31/2 ? counter clockwise (measured on balancer) or to first lower water pump bolt (See Figure 2-9).
This procedure will position the engine so that no valves are close to a piston head. This is 30? BTDC.
3. Before installing bolts through shaft be certain that ring around shaft is installed with ? split? at bottom (See Figure 2-10) on 1982 models. On 1983 and later the split is 90? to the right. On 1985 and later no split ring is used.
4. Snug both bolts on each shaft.
5. Tighten bolts evenly to 55 N.m. (40 lb. ft.) torque.”
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Do you have our 6.2L/6.5L Diesel Troubleshooting & Repair Guide?
Have a look at the first two paragraphs in the above link.
Awe sweet! I was going to ask you how much for all your books? Any big bulk discounts? What is your take on the cast iron rockers?Quote:
Originally Posted by More Power
Thanks to Steelsoldiers.com member Hawkman for selling me these beautiful cast iron rockers!!
Got off work and cleaned up the rockers with paint thinner and brake cleaner.
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A Failure point on the cast iron rockers are the sharp edges around the arm. They have been known to crack and break. Prevention is to use a dremel and remove all sharp edges around the arm.
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The retaining spring has been known to break. Prevention is do not over rev the motor and always monitor your oil levels and have a routine oil change. But when it goes, it goes! Buy a new one if they still make them?
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The cotter pin has been known to break. Prevention is not to over rev, pop the valve cover every 100k and replace it.
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It has been documented that the push rod will wear down the hole that the push rod goes into and make the push rod get stuck causing lifter failure and bent push rods. Prevention is to keep your oil clean and changed regularly to prevent unnecessary wear.
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The wear from the ends of the valves look great! No known failures.
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In a nutshell...
I have had 1 set, yes 1 set of cast iron rockers in 3 different 6.2 diesel motors. 2 motors with 200+k miles and the 3rd recently rebuilt 2 years ago and has another 24,000k on them. In fact, just last week I saw the lucky bastard (Friend of mine) drive down the interstate at 70mph, smiled and waived. I have never had any failures on cast iron rockers!
I love them! I believe they fit tighter on the push rod, have less to ZERO side play and I believe they make the motor quieter because of less clatter.
The sets with the split cleats are the more superior cast iron rockers. The first versions have been known to crack.
Back at the farm...
I got the push rods in. Checked to make sure they were straight and on the lifters.
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Then I did a little shake and bake with the rocker arms in a 1 gallon baggie and 15w-40 oil to lube them up.
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Installed... Torqued them to 40 foot pounds with blue thread lock on the ends of the bolts.
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Cleaned off the valve covers old rtv and the blocks rtv with the angle grinder, wiped off the valve covers with some oil and paper towel, cleaned the threads on injectors and injector holes and added anti seize to injector threads. I installed the injectors at 50 foot pounds, glow plugs and sensor after putting thread tape on the sensor. Put cheap sandwich bags with rubber bands over the injectors to prevent stuff going in the ports while I work on the other side of the block.
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We published an article concerning the cast-iron rocker assemblies years ago showing the consequences of excessive wear. And, we discussed how they are inferior to the newer stamped-steel versions... For example:Quote:
Originally Posted by 2INSANE
1- The cast-iron brass-bushed rockers eventually wear into the rocker shafts, producing excessive valve lash. I've seen several shafts that were worn to a point of weakening the shaft. This can happen <200k miles, where the stamped steel rockers appear like new for >500k.
2- The cast-iron rockers are heavy. Lighter components are the better option for the valve train - from both a wear and a performance standpoint. But, in budget builds, they can be cleaned and re-installed if there is no excessive wear.
Back in the early days... engine shops used to re-bush worn cast-iron rockers. All that went away when the newer stamped-steel versions became available and their superiority was recognized.
These pushrods use a different heat treatment on each end. They must be installed in the correct orientation, or excessive wear could result.
Book discount... I asked whether you had our Guide because of the money it could have saved you.
For example, the recommended Fel-Pro head gaskets were engineered to work in conjunction with the Fel-Pro TTY (Torque-to-Yield) head bolts. These bolts provide for a somewhat elastic clamping load that compensates for variations in thermal expansion and the effects of time. Studs work great for a performance engine that is seeing extreme combustion pressures, but they aren't necessary for even a performance 6.5L turbo diesel. As a way of reinforcing that fact, we know that even the Duramax is produced using TTY head bolts. The Guide is filled with time-tested and proven methods/procedures and recommendations that has saved people a lot of money.
The combination of head studs and the 6.2 began as an attempt to help solve the early head gasket failures. The problem was head gasket design and the fact that GM used non-TTY head bolts. The arrival of the new Fel-Pro head gaskets and TTY bolts absolutely solved the problem... when installed correctly. Did you know that Fel-Pro makes a different head gasket for the 6.2 and for the 6.5? Guess who published the first article about using 6.5 gaskets on the 6.2?
FWIW: my 6.5L with stamped-steel rockers has 368K miles on her, and as far as I can tell, The valve covers have never been off. I've owned the rig for the past 15 years and nearly 200K miles.
Casey
Awesome! Thank you so much for that knowledge! Have you ever done a 18:1 build?Quote:
Originally Posted by More Power
Woah! What year 6.5 do you have? What casting number is on your block?Quote:
Originally Posted by arveetek
More power, I don’t want to argue with you in public. Especially since you are more knowledgeable then I am. Your heeds of warning keeps coming to my mind.
You warned me about the Fuel pump mounted to the banks plate.
You warned me about the Arp studs.
You warned me about the rockers.
In regards to the fuel pump location, has there been any reported fires or issues caused by the lift pump being mounted to the banks plate?
In regards to the Arp studs, I had already bought them a long time ago so that money has already been spent and want to save money by attempting to use them again with optimum black. I’ve heard ultra gray is good too.
In regards to the cast iron rockers, I agree they have many failure points. However, the pressed rockers have had failures as well. Mostly from retaining clips breaking and I have read many times the rods have broken before and the arms cracking and breaking off. I’ve heard more negative with the pressed rockers then I have the cast iron ones. Perhaps it’s because the cast iron ones were not in production long enough to get as many reviews. But I assure you I have a set that has over 423,000 mile on them and no issues. It’s like the early 506 blocks. 90% of the time you see crappy ones with cracks, broken cranks, premature lifter failure. But every once in awhile you get a good seasoned 200k early 506 that has no cracks or major issues. Maybe I got lucky with these cast iron rockers like getting lucky with a 200k early 506 with no cracks.
I do very much appreciate all your free advice and I always take note of it and try to decide for myself what demons I want to deal with down the road. Please keep sharing your info. It helps me more then you know!
Yes I will be buying your 6.2 books. In fact I’ll buy them right now! I would love to read what you have to say! ;-)
Payment sent!
I was the first - for on-road use. Peninsular Diesel, a marine 6.2/6.5 engine builder in Michigan, developed the 18:1 pistons for their marine engines. They contacted me in 1997 - looking to expand their market, and with their cooperation I assembled an engine for use in a pickup truck. A full series of articles appeared here in The Diesel Page in 1999 resulting from that experience, and the world was first introduced to an on-road 18:1 6.5L Turbodiesel performance engine - using marine pistons matched with a high-output marine DB2 fuel injection system. You can read an introduction article here:Quote:
Awesome! Thank you so much for that knowledge! Have you ever done a 18:1 build?
https://www.thedieselpage.com/finale.htm
I personally assembled that engine using Fel-Pro head gaskets, Fel-Pro TTY head bolts, stamped-steel OE rocker arms, port-matched heads, and a competition level balanced rotating assembly. In addition, we introduced the world to using the 1997+ 130-gpm factory water pump and dual thermostats on a pre-1997 engine along with a prototype 21" Duramax engine-driven fan.
Before that... I installed a Banks Sidewinder turbo system on the first GM diesel I owned - a 1982 GMC K1500. My experience with re-installing the original mechanical fuel lift pump caused me to recommend a better solution. You'll see just how close the exhaust crossover is to the fuel pump and its fuel lines when you get the system installed. I haven't heard of any fires, but any reasonable person would at least consider the possibility when they see just how tight everything is... knowing the crossover pipe could get hot enough to glow.
No arguments here... I simply want you to have the best chance at success. We've always been here to help people and improve their satisfaction with these engines.
1995. I don't know the casting number. Never had a need to look! :D I have never had the valve covers or heads off; I believe the injectors are original. No major failures... just your typical maintenance items: several PMD's, three injection pumps; replaced timing chain and balancer for good measure before a long trip two years ago; upgraded cooling system; several lift pumps; etc.Quote:
Originally Posted by 2INSANE
I bought the Tahoe from essentially the original owner. Being a Tahoe, it has had a relatively easy life for a 6.5L. I do tow my 21' camper several times a year, but for the most part, she's just a people mover. I think most 6.5L's in HD pickups and such are pushed to their limits a lot of the time and that is why they don't last as long.
I wouldn't hesitate to take my high-mileage 6.5L on a cross-country trip at this very moment.
Casey
I will swap the rockers back to pressed. Better to be safe then sorry. I also plan on doing the cooling system upgrade. I have all the parts for it already.Quote:
Originally Posted by More Power
You mentioned via PM that I should use the HX35W on this old high compression motor. Why would that be better compared to the Sidewinder turbo? Knowing that this high compression motor should not see more the 10 psi of boost? Is it the back pressure and better spooling?
If you already have the Banks turbo, I'd use it. I wasn't sure if you had the kit yet or not. The Banks turbo is non-wastegated, and is somewhat slow to spool (create boost pressure). During a normal cruise of 65-mph in the 3.42 geared 6.2L GMC I owned, I saw practically no boost pressure. When you "get on it", boost responded to more fuel and engine RPM to produce up to about 10-psi boost pressure.Quote:
Originally Posted by 2INSANE
Like most, who installed a turbo on the 6.2, I was hoping to "see it work" a little more. As a consequence of writing for the magazines, I had an opportunity to speak directly... in person, with Gale Banks himself. I asked about the normal boost response of the Sidewinder. He calmly told me "you'll have the boost pressure when you need it." He was right of course, in that towing or accelerating will produce the boost pressure and power increase we all look for.
But.... the Holset HX35W will bolt onto the manifold, has the correct orientation for the exhaust outlet and it will give you a wastegated turbocharger. It would respond to throttle a little sooner, and allow for an earlier power delivery when driven lightly, while having the compressor map and low back-pressure that works for power. I've not tried one, but that's just what I'd do... Again, if you already have the Banks turbo, I'd use it. You can experiment later on if you run out of things to do.
Cast-iron rockers on the 6.2... If I had a nice set, I'd be inclined re-use them. On the other hand, if I were rebuilding an engine and the original cast-iron rockers were bad, I'd not think twice about replacing them with the newer stamped-steel versions. The books you're getting will show you what a bad set looks like.
I do have a full banks kit except their 3” exhaust which does not matter because I already have upgraded my exhaust to 3” stainless with flow master mufflers I can tap into. Also have the Hx35w as well. Along with a complete running 95 6.5 motor with a GM5 turbo, another 6.2 J code with low miles. My options are great!Quote:
Originally Posted by More Power
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After work today I opened up the Driver side of the motor. I got the valve covers off, rockers, push rods, Arp nuts and bolts and the head.
I identified 2 Arp studs that where leaking from the threads.
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Also one of the freeze plugs has a small leak.
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The head gasket looks great! It was a pita to get off because of that copper spray bonding it tighter.
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Looking at the head, you can see the discoloration where the cylinders go with the head. The areas where there is lack of carbon buildup shows me which valves were not opening and closing properly from the lifters that had failed.
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Cylinder 2 shows some whiteish brownish build up. Not really sure what would cause that? The coolant in the cylinder is from me removing the head with coolant still in the head.
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Cylinder 8 has some of that same build up. I did have the timing advanced quite a bit on the injection pump. Could be over fueling?
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I refurbished the Arp studs at the big shop. I’m there a lot... It’s my other home...
Using the wire wheel, paint thinner tank with brushing action and soaking them in the kitchen sink with soap. This house is clean!
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I've not experienced coolant leaks past a head bolt when using the GM recommended Teflon paste on the threads of all head bolts (as shown in the Troublshooting & Repair Guide). This is a non-hardening sealant, and I've wondered about this type of bolt thread sealant actually keeping a seal, but after all the miles we've put on a 6.2/6.5 through the years and have performed a number of oil analyses, I've yet to see any coolant in the oil.
One thing I always do when installing new head gaskets is to chase all of the bolt threads in the block deck and the bolt threads of the new Fel-Pro head bolts using the correct 12mm tap/die (as shown in the Troubleshooting & Repair Guide). That might be a factor in being leak-free.
After a good flush, these engines and cooling systems can benefit from the orange/pink colored Dex-Cool coolant. This coolant doesn't deteriorate, it doesn't contribute to gasket deterioration, and it doesn't corrode any type of metal used in these cooling systems. I switched to Dex-Cool in 1999 for my own 6.5 - the 6.5TD Power Project. Dex-Cool is a lifetime coolant... although, GM recommends a coolant service after 5 years or 150,000 miles, but I've seen Dex-Cool and the insides of the cooling systems after having been in continuous service for 20 years... It all looks like new.
The following link contains photos of the inside of an aluminum water pump (from a Duramax) that ran its original fill Dex-Cool for 18 years without a flush. There's also a discussion about Dex in this piece.
https://www.thedieselpage.com/durama...xwaterpump.htm
Jim
Ok sweet! That is some great advice! I can’t wait to read your books! The dex-cool sounds like a better coolant for sure!Quote:
Originally Posted by More Power