[Custom10]

I am asking for opinions on helpful suggestions, but i think you missed something somewhere !! My short block is fresh from the machine shop and was a sub 60k mile engine when taken apart. I can't imagine a factory GM L82 4 bolt main long block with gm steel crank, pink rods, forged pistons etc would bring $250.00 bucks......Jeezzz

So flame on still needing pump gas street tune knowledge

Hang in there we do read what you are posting. Seems that you are on the right track with the swap/sell/trade idea. Unfortunate that you have to get back in there and tear down again. If you have flat tops at near zero deck you need to keep the SCR and DCR in check. You mentioned pump gas so this now becomes a balancing act between cam & heads. If you plan on an all out tire burner then you probubly won't be driving it everywhere so you can build on higher SCR/DCR, use premium and a big cam. If you plan on driving it around lots and using regular 87 gas then you have some tricky match making to do between heads/cam cause you have the flat top slugs already.

[dry]

Originally Posted by cool rockin daddy

Three things jump out at me. I would get rid of:

1. 882 heads

2. stock exhaust manifolds

3. 600 cfm carb

Gotta let your engine breathe if you want it to make power. Your choking that thing to death.

So even though the heads were ported and 3 angle valve job with the 2.02/1.60 valves they are still that restrictive? the block was zero decked to gain some more comp? What can be done if anything to improve my current set up for the immediate time being---Timing is 42 all in at 3200 to much? Fuel? Remember its a close ratio 4 speed.........Again i am open to all opinions and good or bad, just looking to maximize what i have right now....

[turbolover]

Originally Posted by dry

So even though the heads were ported and 3 angle valve job with the 2.02/1.60 valves they are still that restrictive? the block was zero decked to gain some more comp? What can be done if anything to improve my current set up for the immediate time being---Timing is 42 all in at 3200 to much? Fuel? Remember its a close ratio 4 speed.........Again i am open to all opinions and good or bad, just looking to maximize what i have right now....

42º is Too much, even for that engine, 38º is probably closer to what you need.

All the porting and valve jobs in the world can't make a prince out of that frog (882's). IMO a good machinist with professional integrity would have brought this up to you before you dropped all sorts of money into them. I would also change you cam. Competiton Products, Summit, and a few others sell cam kits for less than $100.

[dry]

Originally Posted by turbolover

42º is Too much, even for that engine, 38º is probably closer to what you need.

All the porting and valve jobs in the world can't make a prince out of that frog (882's). IMO a good machinist with professional integrity would have brought this up to you before you dropped all sorts of money into them. I would also change you cam. Competiton Products, Summit, and a few others sell cam kits for less than $100.

Thanks i will drop out some timing, I agree with you on the heads its just my "wad" has already been shot for the time being i am just trying to maximize right now. As far as the cam it is a retro old school sound and thats what i was looking for due to the # car shows and cruise nights the car sees....It pulls real hard once off the line and up through the gears. I am just trying to find some bottom end and maybe a head change is the only way i can get it. So whats your opinion on carb if the motor is being choked the death how is bigger carb going to help at all?

[Custom10]

post #13 post # 13 post #13

[ericnova72]

Are you unwilling to put headers on it?? This would help a lot.

Current carb could be worked on to help, specifically the secondary spring and the accelerator pump shot.

You didn't need to buy an outdated poor cam design to get "that old school sound", a modern cam grind can give equal sound and significantly better performance.

While the 882's are not the best, with the work that has been done to them they are at least better than stock, you can work around them a little. A cam change and headers would result in a 50hp/75 ft.lbs gain.

If you have to stay with the exhaust manifolds, look at cams for manifold rules circle track racing, they can help.

[Ohio-Dan]

(1) You stated that the compression readings where even across all the cylinders..................What was the pressure reading?

(2) What do the plugs look like? White, Black, Soot, oily, Powdery?


(3) Do you have a vacuum Gauge? If so, what is the idle reading? Does it bounce, or is it steady?

(4) Was the mark on the balancer checked to see if the "zero" was in fact at top dead center? 42* sounds high unless the outer ring has slipped.

[turbolover]

Originally Posted by dry

Thanks i will drop out some timing, I agree with you on the heads its just my "wad" has already been shot for the time being i am just trying to maximize right now. As far as the cam it is a retro old school sound and thats what i was looking for due to the # car shows and cruise nights the car sees....It pulls real hard once off the line and up through the gears. I am just trying to find some bottom end and maybe a head change is the only way i can get it. So whats your opinion on carb if the motor is being choked the death how is bigger carb going to help at all?

Forget the carb talk for now. a 600cfm isn't ideal but its not the end of the world- there's a reason it the most common holley.

If you want some low end the first thing I would get is some decent headers- which will cost some decent money (the cheapo's are crap and not worth anything). After that I would get a cam. Elgin makes a cam that is available through competition products 1785PM is the part number, 274/274 218/218 on a 106 LSA 102 ICL. With headers this is a great cruising cam that is easy on the valve train and low cost. With exhaust manifolds the cam isn't worth crap- the headers will make a HUGE difference here.

Those two changes alone will run you about $400-$500 but will have a big affect on your low end. After that I would look into picking up a set of used heads for your engine off of ebay or craigslist- used but in good condition heads can go from $100-$500 for a good basic iron set meant for the street.

The cam and exhaust first though! You may decide then that what you have is good enough. There are a lot of cars at shows that have engines that are only good enough to get it moving, so if that's what you need that's okay. You got burned bad on those 882's though.

BTW do you have a part number for the pistons you bought?

[Silverback]

OK, lay off the 882's, no, they're not a good head, OTOH, there is no reason why with a good combination you can't make 400hp with them, and if he was making anything over 250 even with the close ratio he should be able to get them to roast...

That said- the whole combination is just mismatched.

The carb is too small, but that's not preventing the wheel spin unless there is a tuning issue.

If you're running the timing you're saying you are and not getting detonation that points at some of the answers suggesting rather low compression. The point that you missed with the pistons is that oversize replacement pistons are often made with a shorter compression height so that when the block was bored and decked the piston will sit lower than stock. this and the big 70some cc chambers on those heads isn't helping you at all.

The cam is pretty old school... it's bleeding off a lot of cylinder pressure down low and not giving you much breathing up high, essentially not getting you much of anything but a performance cam sound...

Smaller chamber heads (even junk OEM castings), bigger carb (around 750cfm), and while you're there a more modern cam design and a good exhaust will get you a long way towards where you want to be... My exact choices would depend on what you have available and intended usage, but most importantly that the parts match each other.

[cobalt327]

I hadn't noticed that this deal was using cast iron exhaust manifolds, good catch.

That said, a set of inexpensive long tube 1-5/8" diameter headers w/thick flanges is ALL you need on your set-up. There's not anything to be gained from using large diameter and/or equal length headers in your case.

Then, spend the money you save from not buying some set of unnecessary racing pipes on the rest of the exhaust system- dual exhaust pipes (>/= 2-1/2" preferably, but no smaller than 2-1/4" dia.) w/a pair of low restriction turbo-style mufflers and a cross over pipe connecting the two sides, located behind the collector and in front of the mufflers. Put the mufflers as far rearward as possible.

[dry]

Originally Posted by Ohio-Dan

(1) You stated that the compression readings where even across all the cylinders..................What was the pressure reading?

(2) What do the plugs look like? White, Black, Soot, oily, Powdery?


(3) Do you have a vacuum Gauge? If so, what is the idle reading? Does it bounce, or is it steady?

(4) Was the mark on the balancer checked to see if the "zero" was in fact at top dead center? 42* sounds high unless the outer ring has slipped.

1. Compression is 135-137 across the board with a good snap on gauge

2. Plugs seem alittle on the rich side

2B. Fairly strong Gas smell no leaks when shut off

3. Vacuum was low don't remember but was under 7" and bounced to a 7" high

4. The ring is solid and balancer was checked with TDC

5. Headers are not a problem, just want to get air, carb,fuel, timing, spark etc optimized 1st

[PatM]

Idle Vacuum 7 inches. With that cam, I'd expect nearly double that. What speed is your idle at?

Pat

[F-BIRD'88]

The compression test is very low. Should be 180psi. Where is the missing 50psi?

You should check and verify the actual cam in your motor.
What you are describing for idle manifold vacuum and idle sound does not jib with a mild near smooth idle fireball 290H. 216-216-454-454 More like the larger Fireball 302H 284-284-228-228 480-480 112. Wouldn;t be first time wrong cam in the box.
This larger cam has a soggy low end below 3000 and will contribute to a low compression test result.

The heads have to go. You are giving up a huge amount of torque.
Ported 1.94-1.60 4416 305 heads on this motor would be like night and day.
new aftermarket high perf heads will be like bolting on a afterburner.

with just 135psi compression test there is a error in this engine build.

[cobalt327]

Originally Posted by dry

1. Compression is 135-137 across the board with a good snap on gauge

2. Plugs seem alittle on the rich side

2B. Fairly strong Gas smell no leaks when shut off

3. Vacuum was low don't remember but was under 7" and bounced to a 7" high

4. The ring is solid and balancer was checked with TDC

5. Headers are not a problem, just want to get air, carb,fuel, timing, spark etc optimized 1st

There's something causing the vacuum to be too low- vacuum leak, cam phasing, and/or ignition timing are things to check, beginning w.the ignition timing.

That cam will want a lot of initial timing to get the idle vacuum up. If it's that low at idle, when you drop it into gear, the power valve is opening. If the primary blades are open even a little too much (which is probably the case) this will allow fuel to spill into the engine through the transfer slot.

If it were me, I'd start w/recurving the distributor then sorting out the carb.

Initial timing w/o vacuum advance (plug the hose) needs to be around 18º, total around 36º-38º, all in as soon as you can- around 2500 if you can but no more than 3000 RPM. Then, you need an additional 10º-12º from the vacuum advance. Connect it to a manifold source so the advance is there at idle.

The added advance at idle will speed up the idle speed- which is exactly what you want. Then close the primary blades to reduce the idle speed. This will at the same time, lessen the transfer slot exposure.

Using a vacuum gage, reset the idle mixture screws to give the highest vacuum. Readjust the idle speed as needed.

If this doesn't bring up the vacuum to an acceptable level, you have other issues to deal with. But until the above is done, you'll never know.

[lmsport]

7" of vacuum at idle indicates a basic problem. Perhaps most likely is cam phasing. Are you sure it was not 7psia, which would be 14" mercury? I have seen some scanners that do that.

Either way, the 135psi cranking compression is very low for a performance engine. I suspect that mashing the throttle stalls air flow in the intake resulting in a huge bog. You will have to add alot of accel pump to cover the bog. Forget about the vacuum advance and lock the dist at 38BTDC.