Worn Valve guides and performance questions

BLAZE45

MECHANIC
1993 HONDA ACCORD
4 CYL
2WD

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 intake and exhaust 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&feature=player_embedded

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.

5 Replies

MHPAUTOS

MECHANIC
31,937 POSTS

Do all the valves, you will be sorry if you don't, how will you feel if in another 5-6 months it starts missing due to another valve problem, doing them all now id just good workmanship, I would never go to all that effort removing a head and not fixing it properly, in my book that is just crazy.

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Friday, March 11th, 2011 AT 6:49 AM

KHLOW2008

MECHANIC
41,814 POSTS

I agree with mhpautos.

You are going for 400 + hp, that would mean everything should be in almost perfect condition and if the guides are loose or out of specs, that would defeat the purpose.

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Friday, March 11th, 2011 AT 12:46 PM

BLAZE45

MECHANIC
380 POSTS

So you would both cut all the seats and valves even if there was not a problem on those cylinders? I can understand replacing the valve guides on the exh. Side. The ones on the intake side don't seem to have an issue. I am trying to be cheap but I still feel if something isn't broke (IE other chambers holding pressure) that the seats and valves may not need to be cut.

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Friday, March 11th, 2011 AT 2:30 PM

MHPAUTOS

MECHANIC
31,937 POSTS

If you want to go down the cheap path with this, keeping in mind your performance goals, so be it, but when it all falls apart, you will know why. I can only say that if it was mine I would be doing the full job ansd nothing less.

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Friday, March 11th, 2011 AT 3:07 PM

KHLOW2008

MECHANIC
41,814 POSTS

Sorry if I missed that part out. Apart from the faulty one, you need not cut the valve seats but at least you need to perform valve lapping, which I believe would be sufficient instead of cutting and that applies to even the cylinder that is deemed bad.

A visual inspection of the valve seat and valve face condition is required to confirm. If the surfaces are too bad you would have to replace the valves as well.