6X head questions

[bandit77]

Hi, I've got a few questions regarding a pair of large chamber 6X heads I'm currently working on.
I've removed a few of the valves to see what kind of condition these heads are in.
There was a fair amount of hardened oily gunk built up on the back of the intake valves which I suspect is from oil being sucked in past the guides. The first thing I noticed after removing the springs was the complete lack of P.C. seals, ie the seal that slip over the intake guide boss and seals around the valve stem.

Are 6X heads supposed to have these or do they just rely on the umbrella shield and the o-ring that sits under the retainer to control the oil.

Also what type of guides are recommended for a street engine, bronze or iron?

Thanks

Ken de Vries

[bandit77]

Hi, I've got a few questions regarding a pair of large chamber 6X heads I'm currently working on.
I've removed a few of the valves to see what kind of condition these heads are in.
There was a fair amount of hardened oily gunk built up on the back of the intake valves which I suspect is from oil being sucked in past the guides. The first thing I noticed after removing the springs was the complete lack of P.C. seals, ie the seal that slip over the intake guide boss and seals around the valve stem.

Are 6X heads supposed to have these or do they just rely on the umbrella shield and the o-ring that sits under the retainer to control the oil.

Also what type of guides are recommended for a street engine, bronze or iron?

Thanks

Ken de Vries

[Vascar]

I can't say which is the best guides for the street but I had bronze guides put in mine. The seals I use are viton Press fit seals. Those seals are very good for the street, and will control the oil from being sucked down. I don't use the umbrellas either.

My original heads had seals around the valve guide on the intake side and an O-ring type seal at the top of the exhaust valve, and both of them had the umbrella shields.

[bandit77]

So did your 6X heads originally have press fit seals on the intake guide bosses as fitted by the factory?
I've seen another pair of 6x's that didn't have them just like mine.
Did you have to have the guide bosses machined so you could fit the viton seals?
The seals I've seen are too small to fit around the guide boss, or is there a larger type to fit these heads?

Thanks

Ken D

[David Kawallek]

Bandit77, some of the 4x and 6x heads were not machined by the factory for valve seals. You will have to have the guides machined to accept any kind of valve seals. I had a set of 4x done by the local machine shop for $12.00 a couple of years ago. I had the heads apart before I took them to the machine shop.

Hope this helps!!