4.0 SOHC heads - shaved?

[BigPip]

I have been searching but haven't found anything...

How far can I shave my heads and still be safe? I figure since they are going to the machine shop anyways, might as well take advantage.

 

[BigPip]

Never mind, I got an answer

 

[Spdrcer34]

Well, what IS the answer?

We would like to have that info...

Ryan

 

[jd4242]

yea whats the answer?im pretty sure the sohc is a interface motor and it has flat top pistons.it will also depend on what cam you are running.so i would say it would not be safe to shave and if you do it wouldn't be safe to shave the amount you need to make a difference.if my memory is correct i think it is all ready 9.8:1 depending on the year,think the newer ones are 10.3:1

 

[Elessar65]

yea whats the answer?im pretty sure the sohc is a interface motor and it has flat top pistons.it will also depend on what cam you are running.so i would say it would not be safe to shave and if you do it wouldn't be safe to shave the amount you need to make a difference.if my memory is correct i think it is all ready 9.8:1 depending on the year,think the newer ones are 10.3:1

I would have to agree, I don't think its really worth doing at all. If they are going to the machine shop then just stick with porting and polishing, oversize valves, and a good cam. IIRC thats all that gets done to full race versions of the motor built for desert trucks, as far as heads anyways.

 

[BigPip]

To many componets depend on that deck height, espically the timing componets (chain and valves-interference head). Its not worth the risk- Like Elessar said, stick to the porting, polishing and bigger valves.

 

[scdix50]

When I did my head gaskets, the machine shop took off .010 to cleanup the spot where the head gasket blowout. It gives you a nice surface for the new gasket. I was lucky, only $560 refurbish for both heads.

 

[BigPip]

When I did my head gaskets, the machine shop took off .010 to cleanup the spot where the head gasket blowout. It gives you a nice surface for the new gasket. I was lucky, only $560 refurbish for both heads.

I can't imagine .010 doing any damage. I am used to taking A LOT off my heads, even angle cutting the heads and having to cut the intake to sit on the heads properly.

The guy at my machine shop was going to cut/ shave the head, cut/grind the valves and clean them all for $300. I have used him in the past on my Taurus, the heads looked brand new. I was really happy with his work.

 

[BigPip]

Speaking of bigger valves... Where would I find oversized valves for this thing at? 4.0 SOHC

 

[Elessar65]

Speaking of bigger valves... Where would I find oversized valves for this thing at? 4.0 SOHC

I'm sure you could go to pretty much any reputable engine builder/speed shop/machine shop and get it done. However, as far as online/mail-order type stuff, I have heard nothing but good things about these guys.
SuperSix Motorsports
One of my buddies has a bunch of their stuff on his 3.8 Mustang and he swears by them. IDK of anyone personally running their 4.0 SOHC heads, but there are a couple of guys on the Desert/Pre-Runner boards that run their stuff and are satisfied.

 

[Elessar65]

Looking over their site, it looks like they have a good amount of tech info about the SOHC motor as well...