Cyl. wall thickness/machining ?s. High-HP application.

[MadPSI]

What's a stock 4.3 block's cylinder wall thickness? After cracking a wall in the last motor and picking up one from a junkyard, the machine shop is telling us that both motors don't have sufficient cylinder wall thickness to make any power. Their numbers were something in the area of .090"-.110".

Is there any specific year/block number (non-Bowtie) that has especially thick cylinder walls? Is the machine shop full of crap? Is filling the jackets a reasonable way to combat this problem?

I know there are plenty of people making good power on stock blocks, does anybody have maybe a spec sheet of dimensions/tolerances of their machine work?

TIA

 

[midnightbluS10]

Check this link.


HTH's

 

[0966Sy]

Try using a block filler to increase the strength of the cylinder walls.

 

[Lynn D. Brown]

Cyl wall thickness

Cyl wall thickness

Erik,

So, what's a block filler ?

 

[THEMADTYPH00N]

Re: Cyl wall thickness

Re: Cyl wall thickness

Erik,

So, what's a block filler ?

Its a compound thats poured into the water jackets to reenforce the cylinder walls.

 

[nick041881]

i have heard that using block filler on a street car causes cooling issues, so i dont think that is a viable option.

 

[Sy769]

Just fill to the bottom of the freeze plugs.


Also the blocks suffer from core shift pretty bad. You should be glad your shop is actually checking the cylinder thickness. You can't just check it in one place though as one side may be good while the other side is thin. You need several measurements.

 

[canadian]

If you're using block filler, make sure to put it in before you get the machining done. Some fillers contract, some fillers expand, some fillers stay the same size when they dry.