View Full Version : Valve seat replacement
01-12-2003, 12:19 AM
I have a set of heads that someone set the valves too deep in. I would like some info on replacing the seats. I am a machinist of 29 years. But I have never replaced a set of seats. Maybe one of you could give me some advice.
01-12-2003, 07:24 PM
I pulled the heads on my pan about 5 years ago. I forget why but I found out the valves were pocketed big time. After checking around I brought my heads to a guy in Nyac NY who was referred by the local HD dealer Reggie Pinks in White Plains NY. It took about 3 weeks, he initally told me one and he welded in a nice set of hardened inserts. I think it and 4 ground valves and seats and springs and guide check cost about $300. The welds didn't look too pretty but who sees the combustion chamber anyways. It turned out to be a huge performance enhancement. 5 years so far without a hitch and I do not add anything to the gas anymore.
I am very cautious about having anyone do work for me, school of hard knocks is why, most people do not seem to care much about doing a good job for money. So I pulled the valves to check everything out and found a fair amount of metal shavings in the head. Good thing I checked.
Head hog has been around for a while and he advertises in the club mag. I probably would have went with him if he was around then. I just wonder how his heads hold up to unleaded gas.
Two others worth checking out are Lake shore HD in Ill. and Short Block Charlies in AZ I know they have a good reputation but that is all I know. Let us know how you make out,
As an aside the New Year is here and my old lady is working on renewing her seat.
01-12-2003, 07:27 PM
As usual I forgot something. The guy who did mine bored out the bronze inlay, heated up the head cooled off the seats and pressed em in. I believe he welded them up to make sure they stayed put.
01-12-2003, 09:27 PM
Or call Accurate Engineering (334) 702-1993. Ask for Mial or Foy (yes, those are their real names). They've been re-working Pan heads since Fido was just a pup.
Carl N. Olsen
01-24-2003, 10:56 PM
I have been replacing valve seats for a number of years and I have the best luck with machining the old seats out by using a live pilot through the valve guide. I leave a little of the old bronze seat at the bottom of the hole. The seats I use are a nickle-chrome alloy that has a matched coeffient of heat expansion to the aluminum in the head so that as the head heats and cools so does the the seat material, thus maintaining the interferience fit of .004-.006. I have had good luck with Rowe cast iron valve guides and Rowe nitrided valves. They are consistant in size and length. I set my stem protrusion at 1.500 inch for stock motors and accordingly for more radical cams. Surface grind and line hone your rocker housings and reface the rocker pads for even contact of the end of the valves and rockers. I cut a 3 angle valve job for better flow with about a .060 width seat. I like to use a .001 interferance fit between the valve and seat and like to have the seat of the valve about 2/3 out from the stem on the valve face. If you have any questions feel free to call me at Carl's Cycle Supply 605-225-5702. If you follow these guidelines you will have a set of Panheads that will last another 50 years.
03-13-2003, 08:09 PM
e-mail this guy firstname.lastname@example.org
I have a buddy who uses chevy valves for replaceing old panhead valves & seats. Might be worth looking into.Consider Price and availalbility.
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