Getting Previously Stored Engine In Late Dads Car To Run Correctly

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
I found this posted on a different web site
I'm having some issues with my 71 Camaro not running as well as it should. It starts to flutter at about 5,000-5,500 RPM, but I know it should run harder.

Some background: This was my dad's first car and he used to race it on the weekends in the late 70s and 80s. His personal best was 10.30 secs at 140MPH in 1/4 mile. He passed away 15 years ago and the car had been in storage for 13 years before I could afford to get it running again. I have had it in several shops but it just doesn't run right- It starts to bog down at 5,000ish RPM and doesn't seem like it wants to go any harder.

I'm trying to keep it as my dad had it and making minimal changes. I did change the rear end from 4.88 to 4.11 gears. The first shop that worked on it cleaned the carburetor, but also changed the jetting (I did not request him to do this). I think he did this to try to get it more streetable.

Here is what is in it:
350 sbc
850 Holley Double Pump Carb
Edelbrock SY1 Smokey Ram intake
292 Heads
Super T-10 4 speed manual
Holley electric fuel pump
Mallory Magnetic Breakerless distributor
Blaster 2 ignition coil
High domed pistons (last mechanic said its at least 12.5:1 or 13:1 compression using a bore scope)
Long tube headers
Holley Line Lock
Hurst Supersport Shifter
Initial ignition timing : 12*

I've had at least 2 shops and 3 different people tell me that basically this set up is all wrong- too big of a carb, too big of an exhaust, etc.
I've put quite a bit of money in it so far to get it running and it doesn't run very well.
It doesn't have the punch it should. I do put premium (93 octane) gas in it and add an octane booster.

Any ideas on what to do?
Do I need to find a shop with a dyno to have it tuned while on a dyno since this is a rare setup?
Are the valve springs weak?
is the motor tired and worn out? I am getting some blowby gasses

I wish I could find an old school engine builder/mechanic to work on it, but have struck out so far.



from what info you posted,
I'd be looking at replacing the valve springs for sure on any engine that sat for 13-15 plus years,
as its very likely they have inconsistent load rates
and verify the cam lobes/ lifters are not worn,
visually and with a dial indicator,
the 5500 rpm power/flutter you mention,
could be ignition, related, valve spring load rate,
(worn valve train)valve spring ,related or improper fuel delivery related,
so its an isolate and test each, procedure time.
AND I'D REPLACE THE VALVE SEALS ALONG WITH THE VALVE SPRINGS
Id check the ignition wire OHMS resistance on every ignition wire and set plug gaps at about .040-.042
the 850cfm Holley NOT too big it can be tuned to work.
remember that smokey ram intake, was developed to help produce a wide power band in about the 3500 rpm-7000 rpm range,
and yet still fit under a z28 hood , that SY1 intake was a very popular accessory for those that could afford one back then,
but even then it cost three times what a typical aluminum single 4 barrel intake cost, I had an SY1 and a vertex magneto, and an 850 holley, carb, on a 12:1 compression 406 SBC I built at one time.
maxresdefault.jpg

it works better on a 383-406 than it ever did on a 302-350,
a tunnel ram intake with dual 4 barrel carbs would be better for drag racing
the later camaro engine compartment is a tight squeeze
index.php

and I'd be doing a leak-down test on the rings/valves and if you can,
It would be useful if you knew and could post info on the fuel/air ratio about every 1000 rpm and the ignition advance curve
that SY1 intake REQUIRES a rather rich accelerator pump cam and squirters,
http://garage.grumpysperformance.co...olley-accelerator-pumps-cams.1790/#post-73644

http://garage.grumpysperformance.co...ectly-and-get-it-to-last-cam-install-info.90/

http://garage.grumpysperformance.com/index.php?threads/fuel-pressure-regulators.635/

http://garage.grumpysperformance.com/index.php?threads/setting-up-your-fuel-system.211/

http://garage.grumpysperformance.com/index.php?threads/leakdown-compression-test.881/#post-56489

Id also verify you have a rock solid and steady 5.5 psi-to-6 psi of fuel pressure at the carb inlet port
during the full acceleration run,

, can you post clear color pictures of the spark plugs after a hard acceleration test run
btw those 292 heads are 70 year old technology
threre are much better heads available that could easily boost your engines potential power
for those that never worked with one , this is a smokey ram intake:D
sy111.jpg

sy33.jpg

sy22.jpeg

sy1b.jpg
 
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busterrm

solid fixture here in the forum
I had one on a 355 with solid flat tappet cam, it had the popular double hump heads, about 10:1 comp. It ran great above 3000 rpms. But was real sluggish below 3000. Good intake for racing, I pulled it, sold it to buddy for his drag car. He bought the dual quad top plate and put it on his V8 Vega and kicked a few asses with it.
 
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