Panhead oem valve seat material

Oem bronze alloy used for cast in valve seats

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clunker1
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Panhead oem valve seat material

#1

Post by clunker1 »

I'm considering experimenting with tig weld build-up of oem valve seats. I wanted to start off on bronze rings the size of valve seats and after testing the weld overlay, try it out on junk heads.

I'm having trouble getting started though because I cannot find the specific bronze alloy used by harley davidson.

Anyone have any leads?
Thanks
Larry
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Re: Panhead oem valve seat material

#2

Post by Larry »

My concern would be weld shrinkage.
RooDog
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Re: Panhead oem valve seat material

#3

Post by RooDog »

That's how we shrink to remove the races from the fork head bearing cups....
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flat38
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Re: Panhead oem valve seat material

#4

Post by flat38 »

The melting temperature of bronze is 1700 to 2000*F depending on alloy and the melting temp for aluminum is about 1200*F. Having the head melt around the seat while welding could be a bad thing.
clunker1
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Re: Panhead oem valve seat material

#5

Post by clunker1 »

I'm aware of the melt point issue and the shrink issue. If anyone has welded aluminum, you know it takes a lot of heat due to the cond7ctivity of aluminum.

I was thinking of a low heat input with s9mething like a pulsed arc and spotting around the seat until it is overlaid. Tig is so localized at low amps that 3ven the heat affe ted zone can be managed to be very small. Maybe it is a fools errand. If anyone has tried it or know of it failing, then so be it.

My understanding is that the original seats were quite soft and maybe even brass? In that case I'd likely choose a filler metal more suited to a modern valve seat bronze rather than match the existing.

Only other option is flame spray like Don at head hog did which requires quite an investment in specialized equipment.
Dennis
clunker1
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Re: Panhead oem valve seat material

#6

Post by clunker1 »

Sorry for the fat finger typing issues. Forgot to mention that if no one raises a sure roadblock, I plan to press mock seats into aluminum and destructive test/ cross section after overlay weld. This is another reason I want to duplicate the original valve seat material for weld coupons.
Thanks
pan620
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Re: Panhead oem valve seat material

#7

Post by pan620 »

Search valve seat material there are at least 2 threads about it Panhead valve seat material ???, valve seat material
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