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Engine for '77 Corvette

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P161911

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Engine for '77 Corvette

PostMon Mar 05, 2012 2:14 pm

I FINALLY sold my Z3. Now I'm hoping to use some of those funds to go towards a new engine for my 1977 Corvette. The current 180HP L48 small block jumped timing about 16 years ago and the car has been sitting since. That engine was tired anyways. I want to get it running again with somewhere between 290-325+ HP as cheaply as possible. The options I'm looking at are:
1) Iron block LSx truck engine. The all aluminum LS engines are too expensive and I would probably need new springs with those. This conversion has been done lots of time, but there are a lot of small hassles to deal with that seem to start adding quickly to the cost. The choice here is two-fold, attempt to wire up the existing FI system that comes with the engine or scrap it all for a carb intake conversion.
2) Rebuilt/crate motor. This solution would be plug and play. Just not sure exactly how complete I would want to get the engine.
3) Rebuild/hop up the existing engine. This would require finding a good local machine shop and maybe doing a lot of the assembly myself. Would probably bump up the compression, change the heads, change the intake, change the cam, and change the carb.

I will probably keep the existing TH-350 transmission for two reasons. One it isn't worth fighting the battle with the wife to go with a manual and two to keep cost down. I can always go back and add a 5 or 6-speed later.

Thoughts?
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LeftofLucky

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Re: Engine for '77 Corvette

PostMon Mar 05, 2012 9:21 pm

Oh this is a fun one. I definitely vote iron block LS. You can pull some really impressive stuff out of an old iron block.

Have you thought about an LT1? Not particularly attractive, but they make good power, are dirt cheap and super reliable. Just a notion.

Also, as a reminder as to what can be accomplished with an L33:

http://www.autoblog.com/2011/10/24/flyi ... in-review/
"Then you're trapped in your lovely nest, and the things you used to own, now they own you." ~Chuck Palahniuk
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P161911

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Re: Engine for '77 Corvette

PostWed Mar 07, 2012 9:03 am

I have experience with the LT1 and DON'T consider them super reliable. I had a '94 Vette and a '96 Z28. Both had lots of problems with the Opti-spark.
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LeftofLucky

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Re: Engine for '77 Corvette

PostWed Mar 14, 2012 9:21 am

Ah yes, the cursed Opti-Spark. Good point.
"Then you're trapped in your lovely nest, and the things you used to own, now they own you." ~Chuck Palahniuk
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HDJ

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Re: Engine for '77 Corvette

PostSat Mar 17, 2012 1:57 pm

I don't actually have any experience with engine swaps for '77 Corvettes, but my preference would go towards a crate motor. I have no idea how much these things cost, but you can get the plug-and-play ease of installation and a new engine that you get to wear out.

It seems unlikely the current engine will live very long by the time you get to your target hp figure. The crate motor is designed for your target figure already. I came across this website for a GM ZZ4 crate engine swap:
http://corvettec3.ca/zz4.htm

I just did a quick search of what a ZZ4 engine cost. Turn key, it's like $6,500.... Maybe a used iron block is a better idea. It's easier to sell the wife that you need to spend a lot of time on the car than that you need to spend $6,500 on a engine AND lots of time on the car.....
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Mad_Science

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Re: Engine for '77 Corvette

PostMon Mar 19, 2012 11:58 am

+1 for OG smallblock crate motor (or equivalent), provided the goals are maximum power per dollar and time spent driving Vs time spent swapping. It'll drop right in place and you can bolt up everything that's there now...even if it's not a good idea.

Compared to the wheezy original motor (or, you know, not driving at all), even the basest smallblock crate will feel awesome, and for a few more bucks you're in the mid-300hp range. Check Summit, Jegs and eBay motors. I'd suggest a long block with a spiffy intake, 600-something CFM carb (I prefer Edelbrock) and non-points ignition.

Here's a beastly 383 for $3400:
http://www.summitracing.com/parts/MLL-BP3834CT1/
You'd be running and rocking for under $5k. Adjust up or down depending on budget and willingness to shop around (used intakes are a good buy...it's not like they wear out or require rebuilding).

Depending on budget and risk tolerance, you can probably find your way to a similar motor by going used/rebuilt via your local craigslist. Obviously there's the risk of someone selling a "My First Engine Rebuilt (tm)" or buying from Methy Jimbos House of Engines, but typically the really bad ones fail a basic sniff test.
"If life gives you lemons, make lemonade. If like gives you crap, don't make a beverage out of it."
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P161911

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Re: Engine for '77 Corvette

PostFri Mar 23, 2012 6:45 am

My budget for this project keeps trending downward. Right now I'm looking at junkyard Vortec heads, a new intake, and a rebuilt bottom end, maybe with a 383 crank, and a new carb and cam. I'll probably start with the engine dis-assembly and see how much machine work might be needed. I do have access to a Haas 3-axis CNC, but don't really know how to use it and don't have the right tooling to do engine work.

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