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Discussion Starter · #1 · (Edited)
As some folks here can likely understand, the funds for my project truck have tightened considerably. The engine I was going to rebuild was a good running unit with about 200,000KM (120,000miles??) I wanted to turn it into a 383 but am now considering throwing a cam and a pair of (used) cast vortecs on it to revive it for a while. The cylinder wear measures out from .003" to .008" (all but one are within .005") Should I bite the bullet and rebuild it or would it get a new temporary lease on life if I added a few parts?

At the very least I was going to reassemble it and get my project running and driving and rebuild the motor when the cash comes available.

What do you guys think?
 

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Hates: Liver. Loves: Diesel
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From your measurements, I assume you have it apart? If so, I always recommend machine work before you re-assemble it. I was never part of the re-hone and re-ring crowd. If you have a tired engine, then the cylinders are out of round or tapered, or otherwise worn. Putting new perfectly round rings in an egged bore never made sense to me, especially when an overbore and new pistons are so cheap. For an extra $250 for a bore and pistons you can have a much better engine when you're done.

If its still together and making good compression, go for the vortecs and cam. The cam only costs a bill and the heads can be reused.

But, once its been disassembled, you might as well spend the money and get the machine work done. Assembling questionable parts is a 50/50 recipe for wasting money on parts.
 

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Discussion Starter · #3 ·
Thanks Curtis.

The motor was running when I bought it, but the prev. owner removed some accessories, so I did not have a chance to do a compression test.

I only have the heads & intake removed. The rotating assy is still intact. The bore with the .008" is out of round (.005 - .008") If this wear does not seem signifigant, I was planning on just swapping heads, intake & cam only until I can afford to rebuild the shortblock. (Plus a new oil pump & timing chain) I would not replace rings etc until I had it bored out.
 

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Gearhead forever said:
Thanks Curtis.

The motor was running when I bought it, but the prev. owner removed some accessories, so I did not have a chance to do a compression test.

I only have the heads & intake removed. The rotating assy is still intact. The bore with the .008" is out of round (.005 - .008") If this wear does not seem signifigant, I was planning on just swapping heads, intake & cam only until I can afford to rebuild the shortblock. (Plus a new oil pump & timing chain) I would not replace rings etc until I had it bored out.

Marlan Davis dyno tested a 400 Pontiac with 50% leakdown then rebuilt it and only gained 16 lb/ft and 26 hp using used +.030 pistons and the same old cam. A 4 % torque gain, and a 8 % hp gain.

Hot Rod Engines Magazine, Fall 2006, page 34, "Junkyard Jewell, Pontiac 400"

If it were me I'd just slap the top end together like you want and run it and have fun. Lots of guys run $ 100 junkyard short blocks with great top ends at the strip and when they blow they just stick another short block back in.

Been there, done that :thumbup: Ran one 302 Ford that measured .080+ on a .060 and only pulled it because the new 5.0 was ready. And it had 4 broken hydraulic lifters.
 

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If you were going through the effort to take it to the machine shop.Here's a site that has stroker kits for a good deal.
www.enginekits.com
there's nothing really wrong with using stock parts.Im assuming you want to swap to vortec heads to raise compression?if so you could have a nice assembly going.What I would do is.Do what you were doing with the engine right now.To get it running.Then find another one to start rebuilding the way you want.Then when you're ready just swap everything over to the other engine.
 

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Gearhead forever said:
Thanks Curtis.

The motor was running when I bought it, but the prev. owner removed some accessories, so I did not have a chance to do a compression test.

I only have the heads & intake removed. The rotating assy is still intact. The bore with the .008" is out of round (.005 - .008") If this wear does not seem signifigant, I was planning on just swapping heads, intake & cam only until I can afford to rebuild the shortblock. (Plus a new oil pump & timing chain) I would not replace rings etc until I had it bored out.
In that case I'd just bolt on the heads and run it. If it ends up smoking really bad or breaking internally, the only thing you're really out is your own labor of assembly. You have a good chance that it will be fine, and if it isn't, tear it down and build the 383 :)
 
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