Tucker tungsten alloy valve seats

These are the best valve seats I've found. They seem to last forever. No pitting or recession. They require a tight interference fit of .007" in Norton alum heads but thats not a problem when you heat up the head. I've used them in street bikes, race bikes and propane V8 engines which eat up regular valve seats. I've never had to replace them. These are hard seats and I use Neway cutting tools to face them (machining is slow due to their hardness - so you want seats with the basic angles already cut). Custom sizes available. After my experience with them I would never go back to a weaker softer material.

• High quality tungsten alloy – exceptional performance at high temperatures
• Works with all fuels – anti-pollution gasolines, alcohol, diesel, L.P. , gas , natural gas
• Work hardens during run-in – Hardens to 50 Rc , tougher than the competition

Phone 800-362-7321

Interesting product. In theory, Be-Cu or one of the bronze alloys, like AMPCO 45, might be better in aluminum heads, primarily because of the better heat transfer and a thermal expansion rate closer to that of the head. But based on your experience with them, the Tucker seats are also appropriate for our Nortons. Always good to have alternatives. I've had good luck with both Be-Cu seats (particularly with Ti valves) and AMPCO 45 seats in aluminum heads, but that's mostly on race engines that had plenty of hard use, but not a lot of mileage.

Ken

lcrken said:

Interesting product. In theory, Be-Cu or one of the bronze alloys, like AMPCO 45, might be better in aluminum heads, primarily because of the better heat transfer and a thermal expansion rate closer to that of the head. But based on your experience with them, the Tucker seats are also appropriate for our Nortons. Always good to have alternatives. I've had good luck with both Be-Cu seats (particularly with Ti valves) and AMPCO 45 seats in aluminum heads, but that's mostly on race engines that had plenty of hard use, but not a lot of mileage.

Ken

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The heat transfer and thermal expansion is why people use the bronze alloys but I don't think its anywhere near as important as a tungsten seat that outlasts the bronze alloys by a huge margin. I don't see any thermal expansion or heat transfer problem whatsoever with the tungsten alloy - just use the .007" interference, heat the head to 300 to 350 deg, chill the seats install them quickly and forget about them. TI valves are another story I agree but I think anyone who used the tungsten alloy for steel valves would never go back. The only time they need refacing is when you change the guide. I've been using them for 15 years with no problems - only problems solved.

See head build vid on installing seats (at 0:30). Next thing I'm going to try is to temporarily glue the seat to the installation mandril with contact cement befor chilling - they should install ina few seconds.

Why would you use titanium valves in a Norton Commando motor ?
Your valve timings and lift rates are not usually designed for very high revs, and the bottom end usually gives up first when you consistently rev over 7000 RPM.
The Seeley G50 which Bill Horsman used to ride in Australia had titanium valves with quarter inch diameter stems. But the G50 valves were much bigger than Commando valves, so their weifght meant something..
Titanium does horrible things when it is subjected to impact - it reduces in dimension very quickly.
I would use it to make valve spring retainers, but not where it is going to cop a beating.
It is probably OK, if your thinking is only short term. They probably use titanium for valves in MotoGP, but classic bikes are not that, unless you really need a win.
I never think that way. 'Slow and steady wins the race' ? I have not lightened the valve gear in my 850, nor have I ever changed the valve springs. The top end never really does much hard work. Most road races are 5 lap sprints.
Road bikes are different.

When I road race, I do not play their game. A Commando engine is very different. I never think in terms of very high revs and extremely narrow power bands. The heavy crank in the Commando engine is exremely good, but the bike needs to be set-up to use it to advantage. You go quicker where the others are slower. The Commando motor is much safer in corners than others. You can get the power onto the ground better.
If you set up a bike which has loads of top end, to corner faster, you defeat yourself. With my Seeley 850, the way I corner is idiocy, but effective. I do not need any more horsepower - what I have is enough.

off topic, but since you mentioned AMPCO 45 ken, has anyone had experience with valve guides made of this stuff? MAP sells them, quite a bit cheaper than KPMI C630, and I can't find a source for Colsibro guides on this side of the pond. This is for an A65 project I'm working on at the moment.

I've used the MAP guides on many heads. They fit well, and using a reamer and hone to set clearances, I've yet to have any problems with them. I've used the Kibblewhite guides as well, and the MAPs are a bit easier to clearance.

jseng1 said:

The heat transfer and thermal expansion is why people use the bronze alloys but I don't think its anywhere near as important as a tungsten seat that outlasts the bronze alloys by a huge margin. I don't see any thermal expansion or heat transfer problem whatsoever with the tungsten alloy - just use the .007" interference, heat the head to 300 to 350 deg, chill the seats install them quickly and forget about them. TI valves are another story I agree but I think anyone who used the tungsten alloy for steel valves would never go back. The only time they need refacing is when you change the guide. I've been using them for 15 years with no problems - only problems solved.

See head build vid on installing seats (at 0:30). Next thing I'm going to try is to temporarily glue the seat to the installation mandril with contact cement befor chilling - they should install ina few seconds.

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Great video Jim, but you left out the part about machining out the old seats?

AMPCO 45 and C630 ( UNS C6300) are the same nickel aluminum bronze alloy, just different alloy designation systems. UNS is the generally accepted system in the US. AMPCO 45 is the brand name for the AMP Company's proprietary version of the alloy. They claim that their production process produces a superior version of the alloy.

Ken

acadian said:

Great video Jim, but you left out the part about machining out the old seats?

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Yes I did and I may add it later but there's not an ideal way to do it. One may is to accurately tig weld a steel tube to the ID of the cast iron seat - the seat contracts when the tube cools and you can lever it out (I haven't personally tried this method). Another way is to machine the seat until its thin enough to pry out - this is too risky for me as you don't want to go too far (I haven't tried this method either). What I do is drill a small hole in the seat and try not to drill too deep (but its not a distaster if you put a small divet in the alum under the seat), then I open it up with a larger drill bit or a dremel burr until the seat wall near the drilled hole is thin and weak - hit it on an angle toward the center with a small punch until it cracks, then wack it a few more times so the crack loosens up. Once its cracked it loses its tension and can be pried out.

^^^ a bit like welding a bead around the I/D of a bearing outer race to shrink it.
This works well on bearings though I've not tried it myself on a valve seat but don't see why it wouldn't work.

jseng1 said:

Yes I did and I may add it later but there's not an ideal way to do it. One may is to accurately tig weld a steel tube to the ID of the cast iron seat - the seat contracts when the tube cools and you can lever it out (I haven't personally tried this method). Another way is to machine the seat until its thin enough to pry out - this is too risky for me as you don't want to go too far (I haven't tried this method either). What I do is drill a small hole in the seat and try not to drill too deep (but its not a distaster if you put a small divet in the alum under the seat), then I open it up with a larger drill bit or a dremel burr until the seat wall near the drilled hole is thin and weak - hit it on an angle toward the center with a small punch until it cracks, then wack it a few more times so the crack loosens up. Once its cracked it loses its tension and can be pried out.

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I had a head setup in the mill to machine the seats until thin enough to collapse inwards, but backed away from the idea as it felt too risky. I ended up sending it to a shop with a proper Serdi machine, seats came back like new

Grandad said:

^^^ a bit like welding a bead around the I/D of a bearing outer race to shrink it.
This works well on bearings though I've not tried it myself on a valve seat but don't see why it wouldn't work.

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That might work without the tube but haven't tried it.

heating the head to 350.. C or F?

jan nelder said:

heating the head to 350.. C or F?

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350 F