Special cutter for valve seals?

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travis
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Special cutter for valve seals?

Post by travis »

I need to cut down the OD on the guides on a set of promaxx 9175 heads, as there seems to be no valve seals available for a .545" guide that offers sufficient clearance for a .720" ID valve spring. I have a old comp cams 11/32" arbor and .530" OD guide cutter. All the small diameter seals for a .530" guide say that you need a "special cutter" for these seals, but don't say what cutter is needed. Any ideas? I assume this is so the top of the guide will be shaped correctly?
PRH
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Re: Special cutter for valve seals?

Post by PRH »

Sounds like you have the cutter.

An aftermarket performance head with a guide top diameter of .545 is just dumb.
Somewhat handy with a die grinder.
travis
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Re: Special cutter for valve seals?

Post by travis »

PRH wrote: Wed Aug 10, 2022 9:56 am Sounds like you have the cutter.

An aftermarket performance head with a guide top diameter of .545 is just dumb.
I agree. I was hoping to be able to do this without pulling the heads.

And...I think I may have found the reason this thing has always been a under performer. The as supplied springs are garbage :x
PRH
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Re: Special cutter for valve seals?

Post by PRH »

A typical “ring and band” 11/32 seal can be used on a .545 guide.

Depending on what the spring requirements are for your cam, there is likely something available that would work on the heads, and would also have adequate clearance to the ring and band seals.
Somewhat handy with a die grinder.
hoodeng
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Re: Special cutter for valve seals?

Post by hoodeng »

Manley do cutters for various stem seal diameters, the ones for .530" are,
41710 with .312" pilot,
41711 " .343" "
41712 " .375" "

If you are doing different stem diameters you can buy one cutter head and get pilots separate, alternatively you can turn up pilots. Comp also does comparable tooling as well as a number of other valve train providers.

There is no tooling to my knowledge that can cut guides in situ.
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Re: Special cutter for valve seals?

Post by BillK »

travis wrote: Wed Aug 10, 2022 10:14 am I agree. I was hoping to be able to do this without pulling the heads.
Not sure how you would do that. The cutter needs to be piloted through the valve guide to keep it straight and concentric so the seal will work properly.
Bill Koustenis
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travis
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Re: Special cutter for valve seals?

Post by travis »

BillK wrote: Thu Aug 11, 2022 6:36 am
travis wrote: Wed Aug 10, 2022 10:14 am I agree. I was hoping to be able to do this without pulling the heads.
Not sure how you would do that. The cutter needs to be piloted through the valve guide to keep it straight and concentric so the seal will work properly.
I meant that I was hoping I could just swap springs without having to modify anything
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