only 257 hp and 294 ft torque on the tires


time to throw bolts down the carb and start over this engine is a dog!!!

 

Whats the specs on the motor?

Perhaps you dont have things matched very well?

Put up a spec for us to see.

Sheldon

 

He says 377 stroker, but isn't a 377 a De-stroker? Maybe he should have left the 400 crank in, that would add 25 hp right there. But still must be a bad tune or bad combo of parts.

 

Maybe list your parts, also what was your AFR on the run?

 

As far as i know a 377 could also bea 3.75" stroke 350 with a 4.040 bore.

 

that's a 385 not a 377 there sheldon

 

There could be more then engine problems itself.

A low RWHP, could be from:

Bad intake flow
Bad carb selection
in proper part matching
Bad header flow
Stock transmission
Very mild rear differential
A/F ratio not very good
Low fuel pressure

If i rember correctly your running a TPI system.

If its a stock LTR set up, then you are suffering from a lack of iduction flow. A air foil can bring your TB's air flow to around 850cfm. The stock runners and base wont flow very much, stock runners cant really be ported cause their thin, but the base can be ported, tb wall can be grinded, and if you get siamesed runners, you can siamese the plenum opening for better flow. The Ajustable Fuel Pressure Regulator can do wonders on these engines, with some extra fuel pressure you can actually make a good few extra HP.

The TPI, with a few bucks invested, a few days of port work, and some thought, can produce some massive TQ numbers. Only problem is that the system falls flat on its face betwen 5000 - 5700 rpm dpepending on what parts are in it.

Last thought that popped into my mind, did you do any ECM work?
Perhaps your ECM doesnt know what it should be doing with the extra valve train, bigger flow #'s etc.

Feel free to ask for any more info on the TPI system, have been doing quite a bit of research on this system lately.

Hope this helps.

Sheldon
----------
Gah, i was thinking 357.

My bad.

 

The issue to much cam not enough compression

1976 350 0010 standard bore block, Keith black Hypereutectic pistons

Wheeler 400 crank 5.7 rods Lunati cam 245 duration at .050 thousands

534 lift 108-degree separation I have crane gold 1.6 roller rocker on top of World product angle plug heads weiand X-celerator single plane intake
Demon 750 annular carb

Is was a little lean on the run but not much

There is also a vibration that I don’t like at around 3 grand


Doing the math it is at 9.9 to 1 compression


170 psi static dry cranking

 

I wouldnt say the compression ratio is the only thing holding it back.

My LB9, with a LT1 cam, and a few bolt ons, stock heads, stock TB, etc should be hitting about 200rwhp, with 9.3:1 compression.

The problem must lie elsewhere.

What heads are you running on it?

Sheldon

 

Car: 92-Camaro-RS
Engine: 377 stroker with a demon carb

 

Vibration?

Is it from the valve train?

What pushrods are you using?
What rockers are you using?

 

The heads are word products sportsman II cast iron 72 cc chambers

Crane gold 1.6 roller rockers on top


Stud girdles, guide plates, the damb thing pulls to 7,000 grand however according to the dyno it is a dog

 

One other thing is that all of the pulls where in 3rd gear! That what they told me to do. The car is a 5speed and 1 to 1 is 4th gear!!!

 

Hmm.

The engine seems to have all the potential to be a killer, its hard to decide what may be dragging the power down

If you could make a list of the parts used in the engine, that may make a few things easier.

Potentially it could be a bad match of parts.

How much time was put into the engine thought, planning and assembly process?

Sheldon

 

Dyno pulls need to be in high gear 1:1. If you're in lower gears, you're not getting accurate results.

Go get a race weight. Car, fuel, driver etc. Go to a 1/4 mile dragstrip and give me your mph and I'll tell you how much HP you're getting to the wheels from those 2 numbers.

 

Something doesn't add up. I agree that combo should be an animal. Half or even a full point of compression isn't going to make a 100HP difference- even if your're where you think you are at just under 10 it should belt it out just fine (I'm assuming flattops and 72cc chambers to hit ~ 9.9:1 on that 377). The biggish cam and 9.9:1 compression squares up reasonably well with the 170 PSI cranking compression numbers. Pulling in 3rd gear won't cost you a huge amount (10-20HP maybe).

Possible issues with the combo: I'm thinking ignition timing or camshaft timing (Did you degree the cam? Are you sure of the TDC reading between your balancer and pointer?)

Which X-CELerator intake? The 7546 or the 7547? The 7546 should work reasonably well (I always leave the divider plate out). The 7547 I don't know much about other than it's probably not what you want for a street motor.

Possible issues with the runs: What kind of numbers did other cars put down on the same day as you? Dyno calibrations can differ DRASTICALLY. Had one that laid down 240HP on a Mustang dyno but turned 110+ MPH at the strip in a heavy GTA.

Your clutch wasn't slipping was it?

Last suggestion..... go race a stock-ish LS1 Camaro. If he toasts you, you're defintely down on power. If you walk him good, I wouldn't worry too much about the dyno numbers.

 

1976 350 010 standard bore block, Keith black Hypereutectic pistons
Wheeler 400 crank 5.7 rods

Lunati cam Lun-07103lun 245 duration at .050 thousands
534 lift 108-degree separation
I have crane gold 1.6 roller rocker on top of World products sports man II cast iron angle plug heads WRL-012150-2

Weiand X-celerator 7547-1 single plane intake
Barry Grant Mighty Demon 750 annular carb jets 67 front 75 rear going to 68 front 76 rear Has a 4.5 power valve

Ignition is an accel HEI locked at 36 degrees

Exhaust

Headman shorty headers the old style with 3” collectors
2-½ dual pipes into 3” single over the axle splits to 2 ½ tail pipes No mufflers!!

ZOOM 11” clutch and 400-flywheel Lakewood scatershield T-5 trans

BW nine bolt rear end 3:73 gears and a TA cover on it


The cam degreed out to 106 when we installed it I just put in a 2-degree button over the
Weekend


To keep this on the ground I have an spohn adj torque arm and lower control arms
Sub frame connectors and a wonder bar

I am running a manual steering box


All of this for 250 HP!!!

 

Can’t wait till summer I just don’t believe those numbers
The car is going nowhere right now 2" snow on the ground only 24 degrees outside

Two weeks ago I G - teched the car with friend and myself in it we managed a best of 12.62 at 111.22 mph on street tires. guess that with the two of us in it the car weight around 3800

 

Doing 111 mph at an estimated 3800 pounds, you're making just over 400hp to the wheels. I'd ignore the dyno results. Go to another dyno and do it again.

 

If your using the older G-Tech's there MPH are off, not sure about the newer models. I had two of them at the time and at the track one was 5mph fast and the other one was 7mph, just something to think about before you start figuring out HP numbers.

 

If you're tapping 111+ with 2 people in the car you're making a lot mroe than 250HP, that's for sure.

GTech is a little optimistic on teh MPH but with only one person in the car it probably would do a real ~111 at the strip.