How much can you bore an lt1?

[rebuilt]

I pulled the heads off of the 355 that came in my ws6 to discover deep scratches in the cylinder walls. I believe the culprit was caused by the previous owner not running an air filter in the ram air box and dirt making it into the combustion chamber.:(

[joelster]

.040" shouldn't be a problem at all. I have HEARD that it's a no-go on LT1's to go to .060". Maybe your cylinders will cleanup with just a tiny overbore.

[kinglt1]

I would not go more than .040 over! You should be able to clean it up if you take it another .010. That should put you around .040, since 355's are .030.

[KissMyWhtSS]

Yeah I wouldn't go more than .40 either.

[BLOWNDFIZ]

.040" shouldn't be a problem at all. I have HEARD that it's a no-go on LT1's to go to .060". Maybe your cylinders will cleanup with just a tiny overbore.


I would not go more than .040 over! You should be able to clean it up if you take it another .010. That should put you around .040, since 355's are .030.


Yeah I wouldn't go more than .40 either.

X4

[joelster]

Well, there is a way to go .060" over, it involves hard-filling the block, which really isn't hard to do, but it is more or less a drag option/limited street use option. I have never seen anyone actually bore an LT1 .060" over and then take a measurement of the cylinder wall thickness, it is all rumor to me, maybe someone has some hard proof somewhere.

[Tony Shepherd]

I am running .045 over in mine.:secret:

[James Montigny]

.040" is generally accepted as the furthest you want to go with a stock casting without sleeving.
You can push it further, but you REALLY want to make sure you have it checked out first.
Depending on what you have invested in the block as far as machine work, it may be
cheaper to find a used block and have it bored +.030" instead and transfer your
rotating assembly over.

[Stroked96Bowtie]

.30 over in the car now...and a .40 over sitting on an engine stand:devil:

A guy with the user name jimbob on ls1tech bored his .60 over and ended up with a 40xci motor. I do not believe he had to hardfill but he had access to a sonic machine to have it checked.

Anything over .40 you should take a few extra steps like a sonic check, magnaflux at minimum.

[rebuilt]

I figured .40 was about max. If I can get the balancer hub to come of I'll take it to the machine shop. Hopefully It will clean up with a hone. Any suggestions in getting the balancer hub off the crank?

[joelster]

You need an allen headed bolt about 3 inches long. Bottom the bolt out inside the center of the crank/pulley. You want it thinner than the hub bolt so it doesn't ride against the threads. Put your 3-jaw puller on the hub and align the point into the head of the allen bolt so it stays centered. Fire away with the impact wrench, it will walk right off.

[krill]

Or a steering wheel puller, thats what I used. I had a hard time centering the 3-jaw puller on the bolt so I just used the steering wheel puller but either works.