Timing Survey: High Output Engine Owners

[britannic]

How many of you with the 200HP+ horsepower diesel engines from Avant, Peninsular, Diesel Depot (or other engine rebuilders) know what the timing was set at when it was delivered? Please share the numbers if you know )

What makes this question more interesting, is that the rebuilder has to set the timing at a point that still allows them to warranty their work.

[Dieselboy]

All OliverBuilt diesels (both of them ) come with the original pumps timed to the original marks. Now that's exact!

[Peter J. Bierman]

The Pee build TTD runs with the stock pump, twised up as far as it was going timed on the mark.
Better performance is gained by always powering the HPCA solenoid, so it's a few degrees extra in advance.
When the 300 HP peninsular pump gets mounted the search for the best timing starts again.
No warranty on this engine .

Peter

[britannic]

Hey DieselBoy, that Sub of yours is very tastefully specced out.
A couple of questions on the lift:

Did you shim the diffs to get the driveline angles back to stock, or did you go with a Cardan joint in the rear?

What about the axles, did you set them back or forward, or does the suspension kit provide for that?

[mhagie]

I don't know if my Avant/Banks 6.5 fits the label of a performance engine or not,its a 599 block thats been balanced, decked,J Intake,ceramic coated pistons,head/exhaust ports which are port matched and ceramic coated,gear drive timing set,with new 6.5TDInjectors,Kennedy's glow plugs And a Banks Turbo, W/DB2 4911 IP
Timing according to Jamie at The Diesel Depot is 10 degrees at idle falling off to 5 degrees at 1100 RPM,I don't know anything about timing a diesel so I have not a clue where my timing is compared to others. Do hope its right,Am curious as to what possible horsepower might be.

[britannic]

mhagie: that qualifies! Do you know what it falls to at 2000rpm? 2K rpm is usually where the light load advance stops.

[Dieselboy]

Brittanic:
Most good lift springs take into account some amount of caster correction. My first set of springs were Superlift four-inchers, and I was less than pleased with their quality. They started to get a reverse arch, and only provided some three inches of lift after settling. Custom springs like National or Alcan are very choice, but $500 for a pair is a bit steep. Upgrading to those is one of the last things you do when all other details are covered, and it's just the suspension holding you back. Good out-of-box suspensions come from Skyjacker, BDS, and Tuff-Country.

My new 6" Tuff-Country suspension is ten times better. The front is nice and friendly on the road, and has incredible flex offroad with the swaybar disconnected. I converted from 52" to 56" springs in the rear and retained my tension shackle setup so that I can still tow (article will be posted soon!). The rear springs don't have that much arch really, and combined with my RS9005s, it works really well.

The front driveshaft is working out pretty well. The CV uses GM 3R U-joints, and it has held up to everything I put it through, but then again I don't abuse it. It get's a workout though.

The rear shaft had been working really well with the standard 3R front joint with a slip-yoke and 1350 rear, but now with the new springs, I'm getting some vibrations at 45mph and 75mph. I'm going to go check on the output angle on the transfer case and compare to the yoke angle; I'll shim it from there. Eventually, I want to ditch the NP208, and put in a NP241 with a fixed output. That will allow for a double Carden shaft.

You've got a nice setup with the M1028 wheelbase. They are so light in the rear, they can flex like mad, plus the 65/35 weight distribution helps out when it comes to steep ledges. I think that the best answer for recreational wheelers that use long wheel base vehicles like us is to stick with a good chain case, add a massive skid plate, and build a driveshaft that can take a scrape or two.

The axles are just the standard GM 3/4 ton variety, 14FF rear and 10 bolt front. They are still in the stock locations, but they are in need of some re-location. I plan to move the front forward about 1.5", and push the rear forward about 0.75-1". That should keep my front tires from killing the fenders on full stuff, and recenters the rear tires in the fender wells. There should be just enough room in the fenders to clear 37" MTRs, but they need to be nearly perfectly centered.

If you didn't pick up on it, I'm just as excited fourwheelin' as I am about tuning diesels.

[ 09-21-2003, 06:33 PM: Message edited by: Dieselboy ]

[mhagie]

Britannic,Not a clue I could try Jamie and ask if he knows, I would assume that the pump is set at 10 degree inital advance at crank and from there on its all controlled by the IP.
The 4911 pump was a rebuild so most likely set to stock specs as it was a off the shelf rebuild.
When Installing Turbo I asked Jamie If I should turn up pump but he recomended leaving it stock probably figuring I had more engine than I need for a 1/2 ton anyway.

[mhagie]

Britannic,From your posts I notice you like to off road, does your cab have the normal marks from the box?
Most farmers around here that go messing around out in the fields usually have some really nasty dings on back of cab where box meets cab, box wins made me think that the frames on the pickups flex just a tad too much.

[britannic]

No, but I did dent the cab roof with my head one time, being a little too enthusiastic in my driving down a mountain side .

[ 09-28-2003, 07:03 PM: Message edited by: britannic ]

[Dieselboy]

That CUCV frame shouldn't flex that much at all. It's super thick, and even has some gusseting up near the front bend toward the rear of the engine. That frame, along with cockroaches, will survive the nuclear holocaust.

[mhagie]

Brittanic,In your survey did you recieve enough info on timing to tell me if my timing is right on or a tad too far advanced,I still haven't road tested truck since engine install but can tell you when it starts it sounds like my old 84 6.2 with a lot of diesel hammer, but without driving it I am curious as to how loud it will be after it gets excersized a bit.

[britannic]

Originally posted by mhagie:
Britannic,In your survey did you recieve enough info on timing to tell me if my timing is right on or a tad too far advanced,I still haven't road tested truck since engine install but can tell you when it starts it sounds like my old 84 6.2 with a lot of diesel hammer, but without driving it I am curious as to how loud it will be after it gets exercised a bit.

mhagie: what I'm after is whether the majority of these engines are running TDC @ 1400-2000rpm, or only make their power with more advance. Experience has taught me not to go with the amount of advance that is reportedly safe in an N/A for my turbo.

Have you timed your engine with a meter? Unfortunately, without being able to see your truck, I couldn't even hazard a guess as to how advanced or retarded it is - sorry .

[Animal]

Britannic,

Here

[britannic]

Animal: very interesting article, thanks for highlighting it. Question: is the Cummins a direct injection engine?

[Animal]

Originally posted by britannic:
Animal: very interesting article, thanks for highlighting it. Question: is the Cummins a direct injection engine?

Yes it is, they don't use glow plugs just an intake heater.

[britannic]

Originally posted by Animal:
</font><blockquote>quote:</font><hr />Originally posted by britannic:
Animal: very interesting article, thanks for highlighting it. Question: is the Cummins a direct injection engine?

Yes it is, they don't use glow plugs just an intake heater. </font>[/QUOTE]Retarded timing on my 6.2L indirect inj. reduces power, increases EGTs and produces more black smoke. YMMV, but I think that what works for a DI engine, doesn't apply to our pre-combustion design.

For now, I'm going with TDC @ 1400-2000rpm (with my dual idler gears and timing set @ 1400rpm, TDC ignition is constant through 2000rpm).

[Animal]

Britannic,

This is what I have on the Cummins from Josh Berman (Cummins Tech.), I don't know if it relates to the GM diesel or not.

This is the site I copied it from.

http://dodgeram.org/tech/dsl/FAQ/timing.htm

By: Josh Berman,

Here is a general overview of what happens when you change timing on Cummins' B- and C-series engines. I would imagine that this holds true for any engine that uses a pump-line-nozzle type fuel system; results may be different for larger engines that use unit injectors (on-highway truck engines, for example).


Engine parameter:
IF TIMING is: RETARDED ( - ) ADVANCED ( + )
EXHAUST TEMP: increases decreases
CYLINDER PRESSURE: decreases increases
INTAKE MANIFOLD PRESSURE
(BELOW P-TORQUE) WASTEGATED: increases decreases
BSFC (brake specific fuel consumption): increases decreases
NOX (oxides of nitrogen): decreases increases
HEAT REJECTION: increases decreases
HYDROCARBONS (HC): increases decreases
BLACK SMOKE: 1000RPM increases decreases
BLACK SMOKE: PEAK TORQUE decreases increases
BLACK SMOKE: RATED increases decreases
WHITE SMOKE: &lt; 1000RPM increases decreases
WHITE SMOKE: &gt; 1000RPM increases decreases

[ 10-03-2003, 12:45 AM: Message edited by: Animal ]