[Dwest]

I am currently rebuilding my 93 4.0. I am going to increase the stroke and bore it out .030" or .060", I really want to bore it .060" but I am affraid of running into heat issues. I will be replacing my current 2 row radiator with a 3 row and possibly putting on an electric pusher fan.

Is anybody running a 4.0 that is bored out .060"?

 

[West0n]

with any engine, if you bore it out alot, the cylinder walls will be very thin, this alows it to heat up easier

if you go .060 you probably won't have any trouble, but if something happens you won't be able to rebore any more. To me, there are too many risks or issuses that could be a problem. And the power gain is only minimal

Unless you absolutly need the extra ponie or two, just go with the minimal bore. I would spend the extra $$$$ on a goot cam and head work, if it were me.

 

[Warlock]

Go with minimum bore needed and spend the money elsewhere. As stated, good cam, and head work.

I had a 302 bored .060 over and right now it is junk unless I get it resleeved. Ain't gonna happen.

 

[Krawwler]

i would only go over whatever it takes to clean up the cylinder, even if only .010.

 

[MikeW]

First of all I don't really think any manufacterers offer a .060 overbore piston, do they really?
I don't think its a really good idea.