Largest(Safe) LT1 Bore
People go 396-402 ect beacause of alot of thing like rule limits in racing
You can go 60 but then it becomes weak,in wall thickness and heat transfer ect.. then you would fill the block
LTx head market is expensive if you want to use large cubes 396,Lsx are just so much better design in Head flow and availability,form there is the power
You can go 60 but then it becomes weak,in wall thickness and heat transfer ect.. then you would fill the block
LTx head market is expensive if you want to use large cubes 396,Lsx are just so much better design in Head flow and availability,form there is the power
Fact of the matter is, more overbore = weaker walls and more likelihood of failure. Whether this matters a whit has a lot to do with how hard the motor is gonna be pushed, and how much core shift there was in the bored block.
Xray examination of the block to be bored can help determine if that block will be acceptable to bore 'a lot'.
But yeah, to the original poster, .30 over and stroked is about it, and 383 will live longer than 396 in general. Sure you can push it further, but it gets more costly and the benefits are questionable for the risks.
And yes, both 383 and 396 are daily driveable. Depends on a slew of other factors far more than displacement.
Xray examination of the block to be bored can help determine if that block will be acceptable to bore 'a lot'.
But yeah, to the original poster, .30 over and stroked is about it, and 383 will live longer than 396 in general. Sure you can push it further, but it gets more costly and the benefits are questionable for the risks.
And yes, both 383 and 396 are daily driveable. Depends on a slew of other factors far more than displacement.
Last edited by Boodyrider; Oct 12, 2007 at 08:13 AM.
Why don't you tell us your personal experiences and issues that you have had? I have had several .060 over LT1's and have had zero issues. Then again, all of my motors have been 7000 rpm plus race motors.
Sorry that I offended you.
Daren
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FYI I'm running a .060 LT1 block and 17+ psi boost. Been at full boost many, many times with no problems. I'm betting that most blocks would survive at .090 as long as it's NA, but a sonic check would be needed to verify. I've heard that the production LT1 block is as heavy as a Bowtie block.
Mike
Mike
FYI I'm running a .060 LT1 block and 17+ psi boost. Been at full boost many, many times with no problems. I'm betting that most blocks would survive at .090 as long as it's NA, but a sonic check would be needed to verify. I've heard that the production LT1 block is as heavy as a Bowtie block.
Mike
Mike
The point is, while it's PROBABLY safe to go .060 or perhaps even more, some blocks would have issues with it, and while some 396 or larger displacements would live many years, the most cost effective approach to stroked LT1 power is going to be stay with 383 stroke, and stay with .030 over.
If cost effective is not an issue, get 10 LT1 blocks, X-ray 'em, pick the best, and go for the biggest LT1 you possibly can, just to say you have the biggest one built on a stock block.
I really don't know of anyone that has had a block bored .060 that hasn't had it checked first. I don't know that I would deal with a machine shop that would do any work on a block without checking the structural integrity of the block. That said, I have had zero issues with going .060. Pistons are easy to get. The biggest problem that I see with big strokers is crank clearance at the bottom of the bore. It is easy to grind out too much material and break into the water jacket.
As I said before, the main reason that I would go .060 would be to unshroud the valves.
As I said before, the main reason that I would go .060 would be to unshroud the valves.
I really don't know of anyone that has had a block bored .060 that hasn't had it checked first. I don't know that I would deal with a machine shop that would do any work on a block without checking the structural integrity of the block. That said, I have had zero issues with going .060. Pistons are easy to get. The biggest problem that I see with big strokers is crank clearance at the bottom of the bore. It is easy to grind out too much material and break into the water jacket.
As I said before, the main reason that I would go .060 would be to unshroud the valves.
As I said before, the main reason that I would go .060 would be to unshroud the valves.
Jasper did my stock original LT1 .060 over, without asking first if that much overbore was acceptable or if I wanted to supply a new block. I can promise, they did NOT sonic or x-ray the block first, just bored it and slapped in the pistons. The motor was never quite right; it made less power, had heat issues, made more noise, etc. than it should. (lesson learned, Jasper NOT the way to go. For 500 more, I could have had a new crate motor from GM.) (or a nicely built stroker...)
