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Ebay Surprise--.060 Over Block
Thread Starter
Racer
Joined: Jan 2002
Posts: 293
Likes: 2
From: Warrensburg, MO
Ebay Surprise--.060 Over Block
Arghhhh, I took a gamble and bought a "383" short block off Ebay. When I got it, I noticed that the pistons are TRW forged .060 over (not a 383!). The rest of the rotating assmebly is forged, and worth more than I paid for the short block but I'm seeking experience with over bores.
Can a .060 block still be cooled, or am I setting my self up for recurring head aches? I was planning on running AFR 195 heads with an Air Gap RPM intake and a 230ish duration cam with .500ish lift shooting for around 10:1 compression. Should I just canibalize the internals and start with a new block, or will this 010 block still cut it? Thanks for any advice/war stories.
Jim
Can a .060 block still be cooled, or am I setting my self up for recurring head aches? I was planning on running AFR 195 heads with an Air Gap RPM intake and a 230ish duration cam with .500ish lift shooting for around 10:1 compression. Should I just canibalize the internals and start with a new block, or will this 010 block still cut it? Thanks for any advice/war stories.
Jim
Melting Slicks
Joined: Feb 2003
Posts: 3,053
Likes: 4
St. Jude Donor '03,'11
Is it a 383 or not??? That's what you paid for.
why would a 60 over block have cooling problems. If anything it will cool better with thiner cylinders. Its just that your done after another couple hundred thousand miles. No more rebores. I'm guessing that won't be a problem as most of you guys only put a few thousand miles a year on your cars anyway.
why would a 60 over block have cooling problems. If anything it will cool better with thiner cylinders. Its just that your done after another couple hundred thousand miles. No more rebores. I'm guessing that won't be a problem as most of you guys only put a few thousand miles a year on your cars anyway.
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Safety Car
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
Overheating is only a problem on excessively overbored engines and you need to get to .080 on a SBC with coreshift issues to have either cooling or strength issues. As long as the block has at least .125 on the thrust side, you won't have any issues.
And for turtlevette, thinner cylinder walls pass the combustion heat energy into the coolant faster which wastes horsepower by just making the coolant hot. If you don't have enough cooling capacity, then you have overheating problems. Thick cylinder walls keep more heat in the cylinder to do work. So it works the opposite of how you're thinking it does. The trick with building an efficient engine is to make the heat energy push down on the piston instead of boiling water.
And for turtlevette, thinner cylinder walls pass the combustion heat energy into the coolant faster which wastes horsepower by just making the coolant hot. If you don't have enough cooling capacity, then you have overheating problems. Thick cylinder walls keep more heat in the cylinder to do work. So it works the opposite of how you're thinking it does. The trick with building an efficient engine is to make the heat energy push down on the piston instead of boiling water.
Thread Starter
Racer
Joined: Jan 2002
Posts: 293
Likes: 2
From: Warrensburg, MO
Thanks, guys...makes me feel better about the deal. I do plan on a serious cooling system as the Louseyanna heat will suck the energy out of alot of things.
If a .030 over 350 is a 355, a .060 over 383 (.030 over bore) must be at least a 388. I'm gonna have to do some serious math on head cc size, to avoid untenable compression ratio. Anybody know what a 388 with 70cc heads and .049 head gasket comes out to?
Jimbo
If a .030 over 350 is a 355, a .060 over 383 (.030 over bore) must be at least a 388. I'm gonna have to do some serious math on head cc size, to avoid untenable compression ratio. Anybody know what a 388 with 70cc heads and .049 head gasket comes out to?
Jimbo
Race Director
Joined: Feb 2004
Posts: 12,518
Likes: 19
If you are concerned, have the cylinder walls sonic tested. If the heads are still off, it is a $50 expense. The overbore is not important. The thickness of the cylinder walls(on the thrust side especially) is the overall issue or concern.
Melting Slicks
Joined: Dec 2004
Posts: 2,101
Likes: 3
From: Cruising somewhere in St. Louis, Missouri
Dewitts Radiators seem to be the best around for cooling.... I have had ZERO trouble with a radiator/fan combo from them and they are a supporting member.
Jim
Jim
Racer
Joined: Nov 2004
Posts: 432
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From: Granbury TX
Originally Posted by hawgn68
Arghhhh, I took a gamble and bought a "383" short block off Ebay. When I got it, I noticed that the pistons are TRW forged .060 over (not a 383!). The rest of the rotating assmebly is forged, and worth more than I paid for the short block but I'm seeking experience with over bores.
Can a .060 block still be cooled, or am I setting my self up for recurring head aches? I was planning on running AFR 195 heads with an Air Gap RPM intake and a 230ish duration cam with .500ish lift shooting for around 10:1 compression. Should I just canibalize the internals and start with a new block, or will this 010 block still cut it? Thanks for any advice/war stories.
Jim
Can a .060 block still be cooled, or am I setting my self up for recurring head aches? I was planning on running AFR 195 heads with an Air Gap RPM intake and a 230ish duration cam with .500ish lift shooting for around 10:1 compression. Should I just canibalize the internals and start with a new block, or will this 010 block still cut it? Thanks for any advice/war stories.
Jim
Safety Car
Joined: Oct 2004
Posts: 3,725
Likes: 5
From: Minnesota
Originally Posted by gerry72
The trick with building an efficient engine is to make the heat energy push down on the piston instead of boiling water.
The most efficient engine would be one that wouldn't require cooling which as I recall is what spurred the interest in ceramic engine parts.So Professor, what is the HP difference between a .60 bored 350 compared to an unbored version of the same setup and how much of the HP gained from the extra displacement is lost due to the excess heat transfer?
Could this be a small part of the reason why 383 strokers make better power than an old 400?
OK, so I'm in WAY over my head on this one.
Race Director
Joined: Feb 1999
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From: In Dreams There Is Truth Ohio
The block is a 350, the crank is from a 400 thus making it a 383, right?
Now, if you take a 400 block, throw in a forged 350 crank and get spacers, you end up with a 370 cube.
Now, if you take a 400 block, throw in a forged 350 crank and get spacers, you end up with a 370 cube.
Race Director
Joined: Feb 2004
Posts: 12,518
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Originally Posted by lucky76
I don't understand, is it really a 383 bored 60 over or a 350 bored 60 over? You say .060 over (not a 383). Most refer to a 383 without concern as to how much it's over bored.
Melting Slicks
Joined: Feb 2003
Posts: 3,053
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St. Jude Donor '03,'11
Originally Posted by Pete K
It is a 350 block. The 4.00 bore has been increased to a finished size of 4.060. Actual displacement is 388 cubic inches on his combo. A 383 would be a 4.00 bore opened to 4.030.
