Here is the scoop:
I have an F22a head that I took in to be cleaned and all but one cylinder held 20+ psi of air when they pressure tested the exhaust side and intake side of the head. The machinist wants to re cut ALL the valves and ALL the seats instead of just the one that isn't holding pressure. Keep in mind this engine was running when it was pulled. The goal for this engine is 400+hp and wont see much past 7k.

However, he also took the exh. valve and jiggled it and said that ALL the valve guides also need to be replaced. The intake seem solid just like in the vid posted below while all the exh valves have about this same amount of play in them.

http://www.youtube.com/watch?v=ATuuYCu017Y

I want to avoid the "might as well while you are in there" idea cause that will kill a budget faster then hookers in Vegas. He also told me the head needed to be milled yet couldn't tell me the runout on the head. I am budget racer at heart while he has a 5.9 Cummins torn apart sitting next to my tiny 4 cyl Honda head... Definitely got the small fish feeling going there and didn't feel like he gave the best customer service he could of... Then again I wasn't willing to just jump and have things paid for that didn't need to be done.

My thinking is - clean the valves and then take it in and have just the one cc worked over that won't hold pressure and have the seats in that chamber worked over so it will hold pressure and throw the head back on.

Or- buy 2 new exh valves and 2 intake, lap em and throw it together!

In all reality if it is going to make a 20whp difference if I do ALL the seats and valves vs just the one that NEEDS to have it done I would spring for it...

Blaze

 

TTT

 

I could totally understand a machine shop giving you the cold shoulder for your wanting to cut corners. I don’t understand why someone wanting 400HP would want to save a few bucks on critical machine work.


You’re in their do it once or don’t do it at all.

 

Nicefeet- Thanks for your input, any direction pertaining to my questions?

 

I agree with Nicefeet, if you going for 400 HP you don't want in possible problems later on. Good Luck.

 

Why fix something if it isn't broke? Any other input would be much appreciated.

 

I would define excessive valve guide clearance as “broken.”

By not fixing the problem you’re only going to create bigger headaches down the road, some which include premature seat wear, valve stem seal wear, and oil burning.