Performance enhancements for 82's

[lnirenberg]

New owner of a pristine 82 Collector's Edition. Like evrything about the car but the anemic 200 hp engine. Goal is to push net hp to around 350 hp with similar torque numbers and 275+ RWHP. Clearly not wed to throttle bodies as long as car looks original. Any ideas?

 

[Copdogcorvettes]

I have seen where once the motor is biuld to handle it twin carbs are mounted on the stock intake. It looks stock. Even with a basic stock motor twin 350 4barrel holleys can be used.

Just some food for ideas.

Gary

 

[81 Corvette]

do you want the engine compartment to look stock? If so, i'd say cam and higher compression.

 

[82ColEd]

Welcome..
My first thought was to think about the CCC (the computer) which controls most things engine, you would probably have to strip that too.
Would be a shame though. Do you know whether it's the original engine in there ? Is something actually wrong with it ? Or you are just looking to get some power on those wheels ?
Stefan


PS: Dont get me wrong, i am just asking. Your car = Your choice...

 

[Glensgages]

With-in the fairly narrow parameters you've established (i.e.: "as long as car looks original." ), you're facing an up-hill challenge, I think.

If you follow the Cross-Fire forum, you'll see that guys are porting intakes, swapping cams, fuel-pumps, heads, exhaust, injectors, over-boring the TBs, and changing-out entire ECM units, and even then, they might not achieve 350 HP/TQ.

If the motor is in reasonably good condition (compression, no leaks, etc.), the easiest, and probably cheapest, way would be round-up enough parts to build an N2O-kit (NOS dis-continued that Cross-Fire kit last Fall).

If you over-come your desire to keep it looking OEM/stock, 350 HP with a carb isn't difficult;
if you're starting with an L-83, you've already got 9:1 forged pistons with 76cc heads.

Swapping to 64cc heads will get you close-to 10:1 CR;
add a cam, intake, carb, headers, and you can run all day long on 93/94 octane pump-gas (SUNOCO/AMOCO), especially if you choose aluminum heads, but the next problem may be the early 27-spline 700R4 transmission, or the weak Dana-44 aluminum rear-end.

 

[tcolyer]

New owner of a pristine 82 Collector's Edition. Like evrything about the car but the anemic 200 hp engine. Goal is to push net hp to around 350 hp with similar torque numbers and 275+ RWHP. Clearly not wed to throttle bodies as long as car looks original. Any ideas?

Hello, my hame is Terry. I have an 82 and am pulling around 300-325 hp, with only a few mods. And it looks completely stock with the original TBs. Items changed are cam, heads(305HO gives 10-1 compression), valve springs, roller rockers, street ported the heads, ported exhaust manifolds, Ported intake& remove EGR channel, phenolic intake plate spacer, alluminum spacers under Tbs, adjustable fuel pressure regulator, modified TBs, 88 style fuel pump, '84 computer with aftermarket chip, Gutted catalytic converter and Walker Dynomax muffers.

If you need further details, E-Mail me and I will try to help.

Terry Colyer
82 Silver blue Coupe
86 Red 4+3 Coupe
TCOLYER012@aol.com

 

[lnirenberg]

The car has the original engine and it is running fine. I bought the car for its looks and handling not its rather pathetic engine performance. I want to keep the original block and heads if possible and save the original parts so that if and when I do sell it the new owner can return it to stock if they wish. As to how it looks, I am not at all concerned what it looks like when the hood is open ie stock or not only when the hood is closed. By that I mean I don't want to change the hood or the outside appearance in any way.

 

[lnirenberg]

I already factored in a new and improved rear end although I have been told that the 700R4 is a pretty good auto trans and can handle that level of power/torque with no modifications.

With-in the fairly narrow parameters you've established (i.e.: "as long as car looks original." ), you're facing an up-hill challenge, I think.

If you follow the Cross-Fire forum, you'll see that guys are porting intakes, swapping cams, fuel-pumps, heads, exhaust, injectors, over-boring the TBs, and changing-out entire ECM units, and even then, they might not achieve 350 HP/TQ.

If the motor is in reasonably good condition (compression, no leaks, etc.), the easiest, and probably cheapest, way would be round-up enough parts to build an N2O-kit (NOS dis-continued that Cross-Fire kit last Fall).

If you over-come your desire to keep it looking OEM/stock, 350 HP with a carb isn't difficult;
if you're starting with an L-83, you've already got 9:1 forged pistons with 76cc heads.

Swapping to 64cc heads will get you close-to 10:1 CR;
add a cam, intake, carb, headers, and you can run all day long on 93/94 octane pump-gas (SUNOCO/AMOCO), especially if you choose aluminum heads, but the next problem may be the early 27-spline 700R4 transmission, or the weak Dana-44 aluminum rear-end.

 

[Glensgages]

The car has the original engine and it is running fine. I bought the car for its looks and handling not its rather pathetic engine performance.

Same here.
"REAL CORVETTES HAVE PEAKED FENDERS"
I knew the Cross-Fire wasn't a 'runner';
I didn't how much it wasn't a runner, until I bought my '82.

I want to keep the original block and heads if possible and save the original parts so that if and when I do sell it the new owner can return it to stock if they wish. As to how it looks, I am not at all concerned what it looks like when the hood is open ie stock or not only when the hood is closed. By that I mean I don't want to change the hood or the outside appearance in any way.

I assume you mean USE "the original block and heads if possible".....

Your short-block (block, crank/rod/piston assemblies) isn't that bad of a starting-point for 350 HP, but the cylinder heads..... the best thing to be said for them is, that they 'bolt-up and fit'.
I believe the '82 L-83 heads are small valve (1.940" I / 1.500" E), large-chamber (76 cc), thin-wall castings, that some say are prone to cracking easily.

I already factored in a new and improved rear end although I have been told that the 700R4 is a pretty good auto trans and can handle that level of power/torque with no modifications.

What did you do for a "new and improved rear-end" (just curiousness on my part. My rear-end guy thinks that the Dana-44 is pretty wimpy...).

I think the later ('84-up) 700R4s are better equipped to handle sizeable HP increases, and that 'our' 27-spline jobbies are less-desireable.

I have 2 350" SBC for my '79 Z28, both running on pump-gas;
one has run 14.30s/97 MPH, the other 13.30s/104 MPH, in a 3800 lb car.
If you'd like more info regarding cams, intake, heads, gearing, etc., contact me via E-mail at:
Glensgages@aol.com

Good Luck!!!!!

 

[lnirenberg]

Sorry, new to this site. Where do I find the cross-fire forum?

 

[Glensgages]

Sorry, new to this site. Where do I find the cross-fire forum?

[url]http://www.crossfire.homeip.net/[/url]

 

[lnirenberg]

Thanks.

 

[lnirenberg]

I was just re-reading eveyone's comments and I realized when I said "keep it stock looking" I misspoke. What I meant to say was keep it stock looking with the hood closed. What goes on under the hood is not restricted in any way by a need to keep it stock looking.

 

[Ryan]

I used the Holley Systemax II system from Summit.
You'll get for about $1100 2 alumium heads, dito intake, cam, double roller timing gears and 250 extra horsepower. I did my engine rebuild myself and I kept my original L48 block but added the Holley kit on top. My L48 is a complet beast and can compete with 400 HP cars. I also added aluminum underdrive pulleys, headers, sidepipes,2500 stall converter, edelbrock 750cfm carb., edelbrock reusable foam low profile airfilter, lunatti aluminum full roller rockers.
You don't wanna know what a difference this will do to your C3.
I cannot describe this feeling.

Good luck,

Ryan

 

[lnirenberg]

What year is your car? Were you able to keep the unaltered stock hood?

 

[MoeJr]

Inirenberg lets try and use your stock equipment. First off would be a simple cam change. Crane and Comp Cams make grinds for computer controlled cars. Secondly you need a good true dual exhaust of 2.5 inch pipe. Do simple things like change the air filters out for K&N replacements elements. You have a 2.87 rear end ratio in that car. Get yourself a set of 3.73's and make sure you have the speedo calibrated to that ratio. Also if your feeling adventurous you can have the intake and heads ported a bit. All of this will make the car feel much more snappy. Also a 2400 stall converter would go well with the cam change. I hate to see you dump the cross fire setup on a car as pristine as yours as it does work well when set up right. Also I see you are in Mass. I have a guy up here that can set up these cross fire cars well if ya need someone to do the work.Hope this helps.

 

[4 webers]

The stock rear will support a healthy dose of HP , shock is the killer that destroys driveline components . I have rebuilt a number of these rears , they require attention to detail and proper setup . Aluminum cases grow with heat and this has an adverse effect on preload , and other adjustments made during assembly . Glen made a good point when he said you can make HP with a carb on these engines ,,,,,,,,, and quite easily ! The stock intake is what you might just call a bit restrictive , when that situation is fixed the engine responds like any other healthy sbc .

In short , if you are a purist leave the crossfire alone , I am not a purist and only a chebby anyway you look at it . If you decide to make any big engine changes feel free to email me , I will be glad to help.

George

 

[lnirenberg]

I appreciate your advise and would like to contact the person you know up here who can help me set it up. Do you know if they make updated computer modules for the early cross-fires that will help to maintain a finer calibration or is this angle just a waste of time?

 

[lnirenberg]

I am not a purist when it comes to engine mods, however I found that when I was looking for a car I tended to shy away from those with heavily modified engines because I had no idea if the work was done by an artist/brain surgeon or a butcher. Having just acquired the car I am not thinking about resale just setting up a car that outperforms my main car which is a 340 hp awd Audi S6--kind of a sports car for a car guy with 3 kids. At present the Audi wins the race going away and I can't seem to live with that.

 

[MoeJr]

lnirenberg, Contact me privately and I will give you his number.