S-10 Forum banner

1 - 20 of 64 Posts

·
Boozebag
Joined
·
9,041 Posts
Discussion Starter #1
Since I have seen so many threads about wanting to improve power in the 60*, maybe I can offer some tips on helping these engines perform better.
First, some factory specs:
2.8 V6 (RWD 82-85) RPO: LR2 VIN: B
Engine Description (LB6) 2.8L 60 degree V6 (Carbureted)
Horsepower ([email protected]) [email protected]
Torque ([email protected]) [email protected]
Block Cast Iron
Heads Iron
Valves 12
Displacement 2.8L (2800cc, 173ci)
Bore 89mm (3.503")
Stroke 76mm (2.992")
Compression Ratio 8.5:1
Intake / Exhaust valves 1.60" / 1.30"
Valve lift .347" / .394"

2.8 V6 (RWD 85-93) RPO: LL2 VIN: R
Engine Description (LB6) 2.8L 60 degree V6 (TBI)
Horsepower ([email protected]) [email protected]
Torque ([email protected]) [email protected]
Block Cast Iron
Heads Cast Iron
Valves 12
Displacement 2.8L (2800cc, 173ci)
Bore 89mm (3.503")
Stroke 76mm (2.992")
Compression Ratio 8.9:1
Intake / Exhaust valves 1.725" / 1.425"
Valve lift .393" / .410"

Cam specs on 2.8 TBI pushrod motors:

Stock Cam:
Centerline ATDC = 109* on both sides
Duration at .50 = Intake -196* exhaust – 203*
Max lobe lift at .50 = intake -.263* exhaust -.273*
Rocker ratio = 1.5
Gross lift = intake .395” exhaust -.410”
Lobe separation =109*

The first issue is the factory camshaft in all of the S10 2.8s is JUNK (as far as performance is concerned). The lift and duration is so weak, it produces a poor power band and doesn’t help when power adders are installed. (One of the best things you can do to these engines is getting an aftermarket or GM performance cam. The stock cam duration is very short for low end power but doesn’t allow the engine to breathe well)

Some key points:
1. Intake: The intake manifold of TBI motors is very restrictive. It is best to improve your intake before your exhaust. Although it is more expensive than exhaust, it is easier to design your intake to accommodate future exhaust upgrades than it is to design your exhaust for future intake upgrades. There aren't many aftermarket manifolds available, but a longer duration cam makes ALOT of difference in intake flow. The throttle body should also be on the list of upgrades. Holley did make a 400 CFM TBI to put in place of the Stock 235CFM TBI and of course, the 4.3 TBI and boring the manifold is the best TBI improvement.
The Holley 390 CFM /Edelbrock intake is another good option. There are a few others, but they
require more creativity.

2. Exhaust: The stock exhaust is restrictive. Basically the less restriction, the easier it is for the exhaust to expel itself and makes the motor work a lot less to push exhaust out. This is why headers make such an improvement over manifolds. Manifolds usually only have 2-4 inch runners. The exhaust gas slams into the abrupt enlargement or "log" of the manifold and in turn causes quite a restriction. There are a few companies that make headers for the 60* engine.


Free and cheap mods:
Adding a little timing advance can add some torque in the bottom end sacrificing very little in the top. The theoretical hot spot of a 2.8 is 14* advance at base timing for low end torque and HP. Higher than that will take away from the upper RPM's and may cause detonation (ping).
EGR of course puts inert gas into your cylinders. This effectively reduces detonation and NOX emissions. The bad thing is it also effectively reduces your engine’s performance.
Summary- Get rid of it if you can.
A cold air intake will improve combustion.

GM TBI Specs:
Flow is lbs/hr @ 13psi

GM Part # / Engine / Flow / TBI bore

5235430 / 2.8L / 33 / 35mm

5235203 / 4.3L / 45 / 43mm

5235279 / 5.0L / 40 / 43mm

5235206 / 5.7L PU / 55 / 43mm

17084327 / 5.7L Police / 65 / 43mm

1708430 / Late BB PU / 80 / 51mm

5235231 / Early BB PU / 90 / 51mm

2.8/3.1/3.4 Power improvements:

Stage 1
A. Build a cold air intake. Parts are available on ebay for small pesos.
B. Bore the intake openings and install a larger TBI assembly. You can also install a manual fuel pressure regulator for increased pressure.
C. Advance timing to approximately 12* to 14* base timing. If the engine detonates, retard accordingly, although I think that 14* will be fine.
D. Make sure there are no restrictions in the exhaust system – particularly the cat.
E. Install an electric fan and controller.
F. Check that all tune up components are at peak efficiency. Change your oil @ 3K miles.
G. Make sure your tires are properly inflated – I run 30F and 35R.

Stage 2
A. Install a larger cat back exhaust system. 2 ¼” to 2 ½” is good. The larger will give top end, the smaller for lower/mid-range power. There are many systems available for these trucks through Jeg’s and Summit.
B. Install a high flow cat at least 2 ½” in/out. For the 2 ¼” use reducers at both ends. You can eliminate the cat, but I don’t recommend it due to emission laws.

Stage 3
A. Install a set of headers and run a large Y merge pipe for the exit, unless you run dual exhaust.
2 ¼” pipes from the headers to a Y pipe into the cat is the trick.

Stage 4
A. It’s cam time! Select an aftermarket cam with about .480 lift and .285 duration with a 10* or 12* lobe separation. You will also need new lifters. You can go with less lift/ duration but this is about right for a good power punch. Install a TRUE ROLLER double timing chain. Cloyes makes them for this application. Note how stretched the old chain was. The new unit will not stretch as quickly.

Stage 5
A. Install a set of roller rocker arms. These are not cheap, but it’s the last bolt on that you can do. They come in 2 varieties. 1.6 and 1.5 ratio (stock). The 1.6 will give more lift and a little more power.

If you do all of these stages, expect to spend close to $2K. I shopped on Ebay, Summit and Jeg’s, and IIRC this is approximately what I spent on my 3.4.
The result will be a 2.8 that puts out approximately 155 to 165 horsepower. All of this also applies to the 3.1 and 3.4 resulting in a little more power due to larger displacements.
You can go completely wild and do internal mods, (pistons, balance, porting, bigger cam etc) but that is not the intent of this thread. This will give a healthy 2.8 that will pull up hills easily. Your fuel mileage around town will suffer somewhat, but on the highway it will be ok.
I may have missed some of the minor mods that can be done, if anyone feels I have missed something, please feel free to add on.

Notes:
I have not covered any ignition systems; the ECU controls that with the TBI system.

If you go with a carb option, I am running a non-stock Mallory mechanical advance dizzy. There are other options also.

If you run a TBI system, you will never see optimum performance unless you do a ‘tune’ to the ECM. This involves running the truck on a dynamometer and adjusting the air / fuel ratio and timing for optimum performance. This procedure is somewhat complicated and requires hardware and software to interface the on board ECU with a laptop computer.

If you are really creative, you can install a multi port injection system from a Camaro/Firebird. This is proably the best option for performnce. A good tune and all of the 5 stages, I wouldn't be suprised if you could get 180 HP from a 2.8.

Thanks to s10planet.com, where I plagiarized some information.

AND you know that Confucius has to say:

Man with good 2.8 go up hill easy... :p
 

·
Boozebag
Joined
·
9,041 Posts
Discussion Starter #3
^^ Ha, they might of!
I figured that this might help everyone who wants some more poop out of their engine.
 

·
Should've had a V8.
Joined
·
1,619 Posts
Lots of nice info! This should probably be stickied. I see posts about this all the time
 

·
Boozebag
Joined
·
9,041 Posts
Discussion Starter #6
More interesting info:
Tuning: Why bother?

The rise of electronic engine management allows for the running conditions of an engine to be rapidly and precisely adjusted. Before we talk about anything super technical, it’s worth examining some really basic stuff like, “why should we bother tuning a car in the first place?” ”What can we reasonably hope to accomplish?”
Sometimes we start with an engine that’s running acceptably but we want to slightly change how it operates to achieve our goals. Sometimes we start with an engine that doesn’t run at all because it is so different from the original system that was running that we have to tune it for it to run acceptably. Regardless of whether adjustments are made out of necessity or desire, the answer to this “why bother” question is simple: in a word, it is OPTIMIZATION. Tuning allows us to make the most out of the engine that we have.
What Tuning ISN’T

Tuning cars is often very misunderstood, especially by people who do not do it. There is no magic involved. You cannot wave a magic wand and violate the laws of physics in the name of making horsepower. You are dealing with a computer system that responds to sensors in a predictable way.
There is one golden rule (which I think has its origins in a completely different realm) which applies here:
Garbage In, Garbage Out.

As a tuner, you can only work with what you are given. This may seem so obvious that it is a waste of time to even say it. Trust me. It isn’t. It’s critical. And at some point if you mess around with tuning vehicles long enough, you will get so focused on the knobs and buttons available to turn on your computer that you will forget about the mechanical system you are controlling.
  • Changing a computer program can’t fix mechanical issues.
  • Changing a computer program can’t fix electrical issues.
  • Changing a computer program can’t make more air enter an engine than it can mechanically pump
  • Changing a computer program can’t make more fuel flow through pumps/injectors than they can mechanically pump
  • Bottom line: You can’t make pigs fly by pushing buttons. The physical motor you are working with will define what you do on the computer.
Tuning Possibilities

So if we are inherently limited by the physical engine that we are dealing with, what CAN we typically accomplish with tuning?

Typically, we can:
  • Increase power / torque output of the engine
  • Increase efficiency / decrease fuel consumption
  • Decrease noxious emissions (Carbon Dioxide/CO2, hydrocarbons/HC, Carbon Monoxide/CO, Nitrous oxide/N2O, Nitrogen Oxides/NOx)
  • Control NVH (Noise – Vibration – Harshness)
  • Decrease stress on mechanical components / prevent damage to mechanical components
  • Many of these goals require different operating conditions making it impossible to do all of them at once!
Conclusion

Tuning isn’t magic. Modifying electronic engine control systems lets you get the most out of the physical system that you’re working with. Through tuning, you can choose how to operate an engine in order to achieve the goals that are most important to you, making the compromises you want to make. The goal of this course is going to be to teach you to use a calculator/simple math and data logging combined with an understanding of underlying processes to make targeted and appropriate changes in order to achieve the operating conditions you desire for your engine.

Information courtesy of Craig Moates... Thank you
 

·
Boozebag
Joined
·
9,041 Posts
Discussion Starter #8

·
Registered
Joined
·
334 Posts
I was thinking stock bottom end, she's still pretty healthy. Ive found lots of "seemed like a good idea" brand new parts sitting in peoples garages, so i'll upgrade top end. I want it to sound better, doesnt need to be fast, i love a nice lope! Everyone says **** the 2.8 but it has to last me a couple years while we build the new frame and i find an lsx to build.
 

·
Boozebag
Joined
·
9,041 Posts
Discussion Starter #10
I built a 3.4 as everyone here probably knows by now. It has a crazy cam in it and a complete 3" custom exhaust. It sounds very little like a 60* V6, more like pro stock drag truck with a little higher pitch to the exhaust note. It fools everyone.
When you drive at low speeds, it has a nasty lope and rumble. Not loud, but you know it's not messing around. When you stand on it, it sounds wild.
 

·
Awww..you ain't got shit!
Joined
·
3,312 Posts
email What! for sticky...or is it What?
 

·
Boozebag
Joined
·
9,041 Posts
Discussion Starter #12

·
Awww..you ain't got shit!
Joined
·
3,312 Posts
Seriously man...it is "what?"....that's his username. I emailed him and he made it a sticky.
 

·
Registered
Joined
·
2,134 Posts
They are metric, ALL fasteners on all GM 60 degree V6 are metric.
 

·
Boozebag
Joined
·
9,041 Posts
Discussion Starter #16

·
Boozebag
Joined
·
9,041 Posts
Discussion Starter #18
thanks for the links im prob gonna get a set of http://www.summitracing.com/parts/cca-1414-12 since im not looking for huge amounts of power just gonna do a 3.4 with the 260 cam and roller rockers and 4.3 injectors.

Also thnx for confirming they r indeed 10mm i couldnt remember and googling wasnt showing it up.
Good plan Dood. 1.6 ratio will give a little more power because of the additional lift invlolved.
A 3.4 will give you some pretty good bag with the right combo of parts.
 

·
Boozebag
Joined
·
9,041 Posts
Discussion Starter #19
Seriously man...it is "what?"....that's his username. I emailed him and he made it a sticky.
Cool. I thought it was a joke or something.
Meh, if he sees this and thinks it's worth a sticky, he'll tag it.
All I'm doing is helping out with the same question... over and over... more power.
All of this stuff is from past experience - the way to go. No guess work.
I hope it helps someone out.

Confucius say: Power need? Make nitrous... :haha:
 

·
Should've had a V8.
Joined
·
1,619 Posts
Confucius say: Power need? Make nitrous... :haha:
Nitrous is like a hot chick with an STD. you want to hit it, but you're afraid of the consequences.
 
1 - 20 of 64 Posts
Top