i just knew that they do align boring and decking a block in some machine shops here in Kuwait. i want to know how to measure the material to be removed from the main caps and/or block mains to make sure that the crank and the main bearings will fit right and striaght? do i need to measure the diameter of the crank + main bearings and then that would be the diameter needed for the machined main caps and block mains?

what about decking the block, how do i make sure that i removed the same amount of materia from each bank of the block and the block is striaght at each bank? i'm sure this is something is related to positioning the block the right way before decking it. thanks.

 

you have to trust your machine shop for sure. You must have the correct crush on the bearing, I am sure somebody will chime in and tell you what # that is

easy way to check deck is put n the 4 corner pistons and measure it. all 4 should be equal

 

Jordon, what is crush on bearings?

 

thats what holds the bearings in otherwise they would spin spin spin!

 

2.641" is the target dimension, with a tolerance of +.0006 to -.0004. Align honing requires that you cut the main caps until they're a couple .001's undersize then run the hone through to bring them within spec. The trick is to only cut enough off of the caps to get the main bores round and straight. If you cut too much off, you'll most likely move the main bores toward the cam, which worsens the already too common problem with the LT1's of sloppy timing chains. Make sure you use the fasteners that will be used during assembly, and you should also request that they install an oil pump, and torqe it to specs during the honing process.

 

Joe Racer, thanks for the reply that what i was looking for.

couldn't that sloppy timing chain problem be solved by using thicker main bearings?
or i mean moving the main bores in such away a little down (toward the crank).

or they can use a shorter timing chain.

 

when you align-BORE the mains you actually do have to use a different timing chain for everything to work correctly.

when you align-HONE the mains you DO NOT need to use a different timing chaing, just make sure your machinist does it correctly and tells you the correct bearing size to get or to make it easiest let him order it for you

 

89ProchargedROC, thanks for the tips. i can conclude even if i install splayed main caps and do an align boring without changing the diameter of the cylinder block mains i still can use stock timing chain. isn't that right?

also, what is the difference between align boring and align honing?

 

Align boring is the removal of material via a cutting bit. It is done when installing new caps to a block. Honing is the removal of small amounts of material with cutting stones. Honing is done to achieve the final dimensions of the bores and insure that they are perfectly in line.

 

I personally believe it is wrong to automatically assume the block needs to be align honed/bored. The higher you intend to rev the engine, the greater the need to have dimensions as true as possible. With that said, how high do you intend to rev? 8000? If the block/caps are not showing signs of anything having gone amiss previously, and you do not intend to rev beyond 7000, (Nick can come back with another post if necessary), I question the need, if the specs are within tolerance. BTW, if the parting areas are larger than the vertical dimension check, you could take off a 'ton' and not get major cleanup. Just my perspective.