Steps to build a chevy 350

[eoseitz]

I've got a 74 Corvette Stingray. The previous owner blew the original L82 and stuck a 76 camaro v8 into it. I'm not sure which trim of camaro it is. I know it's a 350, but that's about it.

I've slowly been fixing things on my car such as a busted back bumper and interior. I'm ready to paint the car, but I want to do engine work first.

My question is, does anybody know if this is a good engine to build? Where should I start? I was thinking about finding some old 2.02 camel hump heads, or possibly some edelbrock performer heads. I know the engine already has an edelbrock performer intake and a mild "edelbrock?" cam. Other than that it's pretty much stock. It has an edelbrock 650 carb also. How much horsepower gain would I be looking at with a good set of heads and maybe a set of headers?

Thanks

 

[eoseitz]

Engine in it now is out of a 1976 LM1 Camaro. 350 auto 4bbl 170hp(well at least stock it is. Not sure with the intake, bigger carb and cam).

 

[Crimson Thunder]

The Edelbrock heads will definitely outperform the old double hump heads but,is this motor worth upgrading? Instead of spending money on an unknown (probably low compression) motor, you might want to look into a new crate engine.

 

[Whiteshadow89158]

Agreed, spend the same amount of money on a crate motor.

 

[eoseitz]

I can't afford a $3k crate motor at this time. I was looking for a bit cheaper of a way to get a little extra power. Maybe around $1000

 

[eoseitz]

Also I know the specs on the motor. It's a 1976 Camaro LM1 350. It has a stock bore of 4.00 and a stroke of 3.48. It has 165 HP and 245 ft/lbs of torque stock. The compression is 8.5:1 which is the same as the L82 I believe.

However, I'm assuming it has a bit more HP and torque now. The previous owner switched the intake to a Edelbrock Performer intake and changed the 2 barrel carb over to a 4 barrel 650 edelbrock. He said he turned the crack down 1/100. He may have also put a mild cam, but I don't know the details on that. I switched out the points distributor and put in a 50k volt HEI tach drive distributor.

With the Edelbrock performer heads and possibly a new edelbrock cam to match it, could anyone guess at my horsepower and torque increase?

 

[Crimson Thunder]

I don't mean any disrespect but installing new heads and cam on a 76 Camaro motor is like "putting lipstick on a pig." You will never get the compression ratio high enough to make any power. If you can't afford a new motor right now,check around,you would be suprized how many people have a spare good motor sitting on a stand in there garage.

 

[eoseitz]

What type of replacement engine would you recommend?

 

[Crimson Thunder]

Check out the Blueprint motors in the Summit catalog. Chevy 355 long block 310 hp $2195.00 or 383 for $400 more. 30 month 50k warranty.

 

[eoseitz]

That's over 2 thousand dollars. 310 hp is a good amount, but not that much. I had 2 grand in the motor of my turbocharged laser and it was pushing around 275 hp. I'm sure for that money I could get more bang for the buck building an engine. When I was asking what engine you'd recommend, I meant a used engine to build. Not to mention it just feels a lot better to say you built it, instead of you bought it.

 

[Whiteshadow89158]

Well you could buy a crappy junk yard ls1 motor for 1200 and a rebuild kit for 800. Thats your whole budget. These guys know what their talking about, you can get more power for cheaper with a crate motor. Just save your pennys or find a free motor. lasers are a different breed than vettes, they don't call it American muscle for nothin its always nice to say you built something yourself but its even sweeter when you can actually drive your car.

 

[eoseitz]

I wasn't trying to make it sound like they didn't know what they were talking about. I switched over from building rice burners to a corvette. I'm pretty new to this. haha. On my rice burners I'd add a few bolt on parts remapp a few fuel curves and timing on the ecu and gain 100 hp for dirt cheap. Unfortunately, I'm not familiar with internals yet. I'm working on that though. I hope to get as familiar with american muscle as rice burners.

I found this article talking about cheap power gains from the LM1. Is there more to it than the article says? I've got most the parts they put on the motor already installed. Just don't have the heads yet.

GM 350 Crate Engine Build III - Chevy High Performance

I appreciate everbody's help so far. Oh and the laser was made by Plymouth. I wouldn't buy a foreign ricer......Nobody mention that most of the parts on the laser are made by Mitsubishi. lol. That's how I justified owning it.

 

[Whiteshadow89158]

Lol oh Plymouth, brings me back to my neon expresso days :*). I think your on the right track, heads n headers will help allot. If you have the cash afterwards, you could always upgrade the deff. There isn't a whole lot after that until you go into the internals. If you feel ambitious, you could also try a dual rear mounted turbo setup, thats what ill be doing next summer . Just a side question, have you done anything with the suspension?

 

[Crimson Thunder]

Not a bad idea. Find some 58cc Corvette heads to put on your existing motor to raise the compression. Add a mild cam (less than 220* at .050) with your existing intake,carb, and dist.

 

[Bob Heine]

That's over 2 thousand dollars. 310 hp is a good amount, but not that much. I had 2 grand in the motor of my turbocharged laser and it was pushing around 275 hp. I'm sure for that money I could get more bang for the buck building an engine. When I was asking what engine you'd recommend, I meant a used engine to build. Not to mention it just feels a lot better to say you built it, instead of you bought it.

You spent $2,000 to gain 80 HP on your 2-liter 4-cylinder Laser. That $2,000 crate engine gives you a 145 HP gain over what you have now so it isn't that bad a deal. In this case you already have a decent running engine -- you should be able to sell it to finance the new engine. If you get $1,200 for your old engine, that 350 crate motor is only $800 -- for 145 HP. For $1,400 you could be installing a 330 HP 383 ci motor that puts out 385 ft-lbs of torque (140 more than you have now). The fact that it's a sturdier 4-bolt base that has been dyno tested and comes with a warranty makes either of the crate motors a pretty good deal. Just a thought...

 

[6880 Mike]

The engine suffix code stamped on the pad on the block at the front of the right head will identify your Camaro block.

There are three or four How To Rebuild Your Smallblock Chevrolet books. Purchase a couple, read through them, and rebuild your existing engine.

 

[herminator]

That's over 2 thousand dollars. 310 hp is a good amount, but not that much. I had 2 grand in the motor of my turbocharged laser and it was pushing around 275 hp. I'm sure for that money I could get more bang for the buck building an engine. When I was asking what engine you'd recommend, I meant a used engine to build. Not to mention it just feels a lot better to say you built it, instead of you bought it.

I agree 100% with the custom build and I built it as that is what I did. However, along with parts, you need to consider machining costs.

 

[eoseitz]

That is a thought. I never really thought about selling my motor to get cash for a better one. Do you think I could actually get $1200 out of it though? I've actually been wanting to put a 383 into my car. I figured I'd just buy the heads, intake, carb, ect for now and then have the internal done at a later time.

How hard is it to turbocharge an engine with a carb? I'd say with the current compression I could probably run around 6 lbs of boost. I'm not sure how I'd adjust the fuel ratios without an ecu though. Would I just set the carb to run rich and then bump the timing back a few degrees? I've installed a wideband o2 sensor before. That should be easy enough and let me know if I'm leaning out. As long as my air fuel ratio is close to 14.7:1 I shouldn't have to worry about knock should I? I know there is no hope of finding a knock sensor for a non ecu engine.

 

[eoseitz]

wow. Just started reading up on turbocharging a carbureted engine. It sounds like there are a whole lot of modifications to the carb and fuel system. I'll probably stay away from that. Just curious. Could you use the snorkle off a supercharge for a turbo?

 

[eoseitz]

Found a fairly well priced crate engine from Jegs. It has 260 HP 350 ft/lbs of torque for only $1400. That doesn't seem bad at all. And it's low compression. 8.5:1 I could supercharge it later on down the road if I decide to. Let me know what you think.

GM Performance 10067353 GM Goodwrench 350 Engine & Packages - 1973-1985