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View Full Version : Just got my headers installed Now to turn up the pump?



CryHavocc
03-10-2019, 19:41
So just got exhaust work done. I installed Stan's headers and 2.5" dual exhaust with flow master 40s. Just driving home from shop I did not see much improvement outside of a quiet cab and nice sound. I hope that all of that will change after the pump is adjusted. I have looked up on youtube and found out how to turn it up but how much? some say 1/8 to a 1/4 of a turn? will the turn it up till it smokes then back it off work? If someone has swapped injectors to better match the headers what did ya go with? I also seem to have more white smoke than before is that a common problem with swapping headers I'm not sure how its related.

More Power
03-11-2019, 08:02
Did you do any performance testing with the truck in stock form so you can compare?

Generally, a turbocharger install will benefit from a bump in fuel metering adjustment (generally about 1/8 turn, maybe a little more). Just a free-flowing exhaust will probably require less of a fuel increase.

We did a lot of performance testing here in the late 1990s and early 2000s with the 6.2L diesel, both non-turbo and turbocharged. What we found is that if you did everything possible to improve performance, short of a turbo/supercharger, you can expect a performance increase approaching 10%. A turbocharger installation and fuel metering adjustment adds 40%+.

In either case, I recommend installing an exhaust temperature gauge, which is great to help you adjust the fuel rate - keep it safe. Jim

DieselDavy
03-12-2019, 09:41
I agree with MP on the exhaust temperature gauge.
Please do this first, then you can fiddle with the pump.
Not paying attention to the exhaust temp gets expensive fast.
d

More Power
03-12-2019, 10:28
Because the original 6.2L piston crowns were not anodized, Gale Banks recommended that we consider 1100 degrees F (in the ex manifold temp) as the maximum EGT - for the time it takes to pull the longest grade. I know through experience that this is a safe exhaust temperature.

Anecdotal... I had heard from a turbo 6.2L owner some years ago who pulled a trailer across the state of Texas - in the summer, and saw EGTs in the 1200 range all day long. He reported that he didn't hurt the engine.

My experience with setting the fuel rate for a non-turbo 6.2L is that whenever I began seeing wisps of black smoke, I knew EGT was climbing. The darker the smoke became the higher I recorded for EGT. There is such a narrow window between OK and too hot, that I know that the use of an EGT gauge is the only way you can prevent damage and still push fueling/performance.

arveetek
03-12-2019, 11:58
From my experience, EGT's on a naturally aspirated engine tend to run much higher than a turbo model. I used to tow regularly with my '81 C20 that I swapped in a 6.2L N/A, with Lee Swanger exhaust mods that allowed full 2.5" dual exhaust from the factory manifolds back. I even towed my 5th wheel to the DP Rendezvous in Ohio back in 2001 with this rig. At the time, it was not unusual to see 1200* to 1300* EGT's while towing, with spikes to 1400* on long grades. When I first installed the Pyrometer, it scared the willies out of me, but I soon learned the engine was quite happy at those temps, and no damage seemed to result, even after several years of towing.

I installed a turbo on the same engine with no other mods, and EGT's immediately dropped to a max of 1050* due to the turbo pushing more air through the cylinders.

My opinion is that EGT's are not that critical on a N/A engine, due to lower cylinder pressures. I don't think you can add enough fuel on a N/A 6.2L to cause damage from EGT's. It's only when you add a turbo and increase fuel that problems start to arise. At least that's my opinion based on my experiences! :D

Casey

CryHavocc
03-24-2019, 18:01
So I turned up the pump about 1/8th of a turn clock wise. There is no black smoke when you mash it. So far things are great. As for power seat of the pants tells me its more. takes about 18s to get to 60 mph. the only thing besides headers that are not stock is its got a J code intake W/O EGR. had a J code the whole time and never noticed it.

Dvldog8793
03-25-2019, 07:21
Howdy
I have a 1986 blazer with NA 6.2 milspec. at 60K miles I installed stans long tube headers with open exhaust. I also made a larger airfilter housing and ram air system and cleaned up and matched the intake to the heads. I have an amsoil 6inch racing air filter.
The seat-o-the-pants meter was marginal, definitely an improvement but nothing drastic.
By FAR the best improvement I did to this truck was at 90k miles I had the pump and injectors rebuilt to modern specs. All the injectors were bench matched and the pump was increased by 1/4 turn per the shop that I use for all my pump work. This yielded a very noticeable difference in performance. The only time I see black smoke is when I pull a load or really get my foot into it, and even then it's not bad.
If I had done this at the same time as the headers, it would have been a huge improvement over the existing specs.
All that said, my sons ATS turbo 6.2 will still blow my doors off....BUT nothing, and mean NOTHING, sounds as sweet as a NA diesel at around 2500 with headers! I am lucky I work with all the local cops....:D

Another thing you might want to do is pull the heads and clean them up and replace the gaskets with newer style fel-pros.

Hope this helps!

Dr. Lee
06-07-2019, 15:01
So I turned up the pump about 1/8th of a turn clock wise. There is no black smoke when you mash it. So far things are great. As for power seat of the pants tells me its more. takes about 18s to get to 60 mph. the only thing besides headers that are not stock is its got a J code intake W/O EGR. had a J code the whole time and never noticed it.

Just to give you something to shoot for, at the end of my project to get the most possible out of the N/A 6.2L (bored to 6.5L) diesel, I ended up doing 0 - 60 mph in 9.52 seconds. Read all about it in the book: https://www.thedieselpage.com/62bookcombo.htm
The book even has my old truck and the engine on the cover :D