4.0 heads shaved?

[Purdue72]

Has anyone had a positive gain from shaved heads on the 4.0?

 

[410Fortune]

on your 93 OHV?

Shaved as is in decked?
YOugoing to machine the block too?

Purpose is to gain compression?

 

[SVO]

I took off 5 tenths and noticed nothing.

But I only did that to clean up the runout.

 

[Purdue72]

yeah, 93 OHV / 165k miles

I have to replace the heads, while I was that deep into it I was planning on rebuilding the bottom. Considering cost though, I was going stock on the bottom.

 

[Purdue72]

Is 5 tenths the norm?

 

[410Fortune]

Check out this link:


http://www.4.0performance.com


If you want some performance on the OHV the place to start is the heads....

 

[SVO]

Originally posted by Purdue72
Is 5 tenths the norm?

That's just what I took off to clean them up.

I might have another set of heads here if you need them.

 

[Doug904]

Originally posted by Purdue72
Is 5 tenths the norm?

3-5 Thousandths is the norm to clean up a warped or untrue head surface. Decking the 4.0 head like 10 or 20 thousandths is really useless and just makes the stock weak castings weaker therefore more prone to crack if ran hot.

If you wanna raise the compression on a pre-95 4.0 then go to late model or post 95 heads with a 10cc smaller combustion chamber BUT then get ready to purchase nothing but Premium at the gas pumps because if you don't it will ping.

For the performance gain you could install a camshaft for cheaper and get more performance for your money and not have to worry with buying premium all the time.

Later Doug904.