Polishing 4.0 sohc Head

[Deak]

Hey,

Has anyone polished their 4.0l sohc head? I Have got a line on a set of stock heads, and I will add a KKM intake ( i hate the square filter can never get it open). It will prolly need a new exhaust this year at some time. I plan on better muffler than whats stock. I was wanting to give head polishing a try and figured it couldn't hurt. As far as porting goes can they be ported? I know you could port the exhaust but what about the intake? Don't they use o rings as intake gaskets? I would be going for a stock rebuild/refurbish on the head. I am going to have to replace my rear cassette and I imagine the right head might have some damage so I figured might as well put remanufactured heads on it and a couple of other bits that get old etc. Just wondered if it was worth the effort

Deak

 

[RickOTR]

Polishing the heads would definitely help give you some extra horsepower. However, If you are going to go through all the trouble of removing the heads, then why not have them extrude honed. I have a friend who did this to his explorer, and it showed a gain of 26 horsepower at the rear wheels on the dyno. I am thinking about doing this to my X.

 

[Deak]

I wouldn't be pulling the heads. I would pick up a set at a yard. That way I can take my time polishing the heads and have a second set to polish and sell. Never heard of extrude honed (what does it do) where is that done in the process? I was just planning on a valve job and either polish before or after the job whichever should be done first.

Deak

 

[RickOTR]

Deak,

Extruded honing polishes the intake and exhaust ports of the heads. This involves a machine that pushs puddy like material through the ports and smooths them for better fuel flow. Ford does this to all of it's SVT vehicles and is one of the easiest ways to gain hoursepower. If you are going to go through all the trouble of polishing the chambers, then you might as well have them extruded. My friend paid like $100 a pair, and said it was well worth them money.

 

[racebronco2]

if i can get my heads extrude honed for 100.00, can you get the number ..... i called a company about 3 years ago and they quited me 400.00+ just for the upper intake on a 4.0 ohv

 

[Deak]

So

Do you polish before or after the head job or does it matter?


Deak

 

[james t]

before

 

[RickOTR]

Intake manifolds cost a lot of money to do as the honing process somehow tends to crack the maniflod runners because they are so long. The more putty used, the higher the cost. Also, the shorter the runners, the less chance there is of the putty cracking the part because of the force applied by the putty. The cylinder heads are much stronger, and have short runners. My friend told me the price is now $150.00.