cv67

Sounds like you shouldnt enjoy the car leave it stock and boring.
Sheesh

bluedawg

I agree 120% please dont skimp when it comes to the heads. If you do well here belly aching from now untill you upgrade. Only a rich man can afford sub par parts. 180cc eliminators and a 260ish advertised roller cam and youll be happy. Other wise youl pull the trigger multiple times untill youve gotten were you want to be with used parts in excess. Add the performer intake and use your existing qjet, add long tube headers, accept no substitute for long tubes! Shorties are in adequete, 400 horse all day long. 285hp at the rear wheel through a 3 speed auto Just mine and others .02$

pace1978

Ok, thanks for the input everyone. I think I will just continue with the tune up and work on getting the engine bay spotless. Paint and interior are also original and pretty much mint.

tyancey00

i have to agree with the leave it alone guys.... It is a nice car and good driver. If you want a hot rod, buy one that is not as nice as this one...

qwank

even if you do keep all the parts you take off to put them back on later, once those bolts are removed, it can no longer be a true "survivor".

pace1978

Not to hijack my own thread but can the exhaust manifolds be removed to freshen them up with the engine still in the car?

SWCDuke

There is a fundamental problem that works against obtaining much useable power gain on any '75 to '82 Corvette - the single catalyst exhaust system.

Dave McClellan in his book stated that this system increased exhaust system back pressure by "half an atmosphere", which puts it up in the 10-12 psi range, which is HUGE. Any modifications to increase aspiration will mostly be eaten up by additional exhaust back pressure. A one psi increase in exhaust system back pressure will reduce BMEP by at least one psi, and exhaust system back pressure increases with the SQUARE of flow. It's a no win situation.

Start with some simple changes like optimizing the spark advance map with some lighter centrifugal springs and bumping the initial timing up to obtain 38 total initial plus full centrifugal. Convert the VAC to full time. (The OE VAC is okay.)

This link should help you understand the whys and wherefores.

http://www.metroli.org/pdf/2012%20Na...ingseminar.pdf

You can also do something about the heat stoves and obtain full time cold air induction.

The next step is to replace the OE cat with a modern monolithic design, which offers less back pressure. If this doesn't do it for you, and assuming you don't have to have field emission tests, backdate the exhaust system to the full dual system.

The next step if you want "more power" is internal engine modifications, and the best bang for the buck is to raise the CR to 10.5:1 and massage the heads, everything else OE. Neither this nor any of the other modifications other than any exhaust system changes are visible, and they will get the engine up to 270-290 SAE corrected RWHP, which is respectable for any massaged-head OE SHP small block, and it will still retain the decent idle and low end torque characteristics, which make it pleasant to drive in typical modern traffic. A lumpy, rumpy idle from a high overlap aftermarket cam that kills low end torque will not make for a pleasant driver, nor will 10 MPG or less be any fun.

It sounds like you have a nice original, unmolested Indy Pace Car. Before you screw it up with a Summit catalog, get Dave McClellan's book and read it thoroughly. Get a CSM and COM. Download the '78 information package from the GM Heritage Web site.

Find out what you have and thoroughly understand it before you do anything you will likely regret in the future.

Duke

qwank

yes

cv67

Thats it no more modded motor threads in C3 it will ruin the car

My god you guys

pappy.72

Blower!!!!! Bring it back to stock when or if you want to later on. Should be good with your low compression engine too.

http://www.procharger.com/chevy_chevelle.shtml

jb78L-82

Scott,

Consider yourself lucky to be in on the secret! Only the brothers and sisters on the forum get in on it!!


As for Stans, i bought my McJacks Shorty's back in 2006 and I paid what Stans headers cost now. I wanted a Shorty that would hook up to a stock style dual exhaust.

Always appreciate a good ribbing!

addballer696

When i got my l-82 I wanted more power too. Here's what I did over the course of about 5 years.
-Pulled the catalyst exhuast like SWCDuke mentioned and put in sidepipes. I could feel and notice a great deal more power and cost about 750

- Next I decided I would ditch the restrictive heads and get some vortecs, these go along pretty decent with the L-82 cam and are relatively cheap. This took some other parts like a new intake, but was well worth it and didn't have to pull the engine. Got a very thin gasket and overall bumped the compression up to around 11:1. (only run on premium gas now) set the timing and adjusted the carb and wow tapped into a whole load of horses. This probably cost about 850 total.

Just these two things gave me all the power I needed. I can burn the tires no problem and jump off the line like never before.

Brcmpbl

I'd leave it alone.

Also from your first post, you shouldn't have to touch your rotors other than to clean them up.

iokepakai

I'm all into performance mods,but I would leave this one original...You scored!!

johnnyjaws

ant worth 50gs

augiedoggy

And a 2013 stingray won't be worth anywhere near the equivalent of 50 grand in 2047 either...... what's your point? We all know things depreciate as newer replacement improve.... if they happen to end up being rare or a sought after collectible in 50 years or more they might end up being worth a mint...look at how much an original "blue flame 6 cylinder" vette goes for now.

pace1978

Exactly, I was saying it was around 14k msrp in '78 or 50k in today's money. So if you bought one as an investment in '78 that really didn't work out as expected, right? I think the most you could get for one with no miles and perfect condition is 30k today if you found the right buyer, equivalent of a 20k hit.

DucatiDon

Check out my l82 upgrade thread for what I did to mine. Unless planning on stroking it to a 383, go with afr 180 heads

DaveL82

I have an 80 L82 I bought back in 83 with 29K miles. The car is nothing like stock now but over the years I did a few mods that really helped but were not big changes.

Send your stock rochester carb to someone like Lars or Ruggles to have it set up properly. The stock carb is a very good baseline and when tuned with the right parts it'll be perfect for the motor. Antohter advantage of the Rochester is you can retain the low stock cold air intake, add the 80 electric choke element, and no leaks from carb (threw all my old holleys in the trash and never looked back)

Remove the stock and very restrictive catalytic converter. Run true duals or if you must run a cat get a single system with big tubes and high flow cat. Going into a single pipe is not too bad as it also acts as a crossover.

If you have the L82 aluminum intake its no a bad piece but others can make more power higher up. One of the car mags did a comparison and the weiend (sp?) units was low profile but very good power. If you need to retain the EGR for emissions in your area get an intake that has the mounting cast into it.

The stock rams horn manifolds are not too bad. I dont run tube headers due to leaks and excessive heat causing other components to get brittle under the hood. Even on the track version I run high flow sanderson cast iron headers.

Heads on the L82 don't flow to good and run low compression. Later on you could go with aluminum and raise the compression to 9.5 for pump gas.

Everything is bolt on so do what you want with it. You can get more power without big changes.

Have fun with it.

81$$pit

I'm not a purist by any means if you look at my sig but with that low miles I would pull it out and drop in 383 stroker and keep the L82 unmolested. Another 20 yrs you might be very glad you did.