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351C Forum Tech
Titanium Valves and Seat Compatibility
Titanium Valves and Seat Compatibility
text 335 series Forum
Wiseco Titanium Valve Installation Guide:
Wiseco Titanium Valve Installation Guide:
http://www.wiseco.com/PDFs/Manuals/TitValveInstall.pdf
Dan Jones, Feb 6 2008;
Joe, Feb 6 2008;
Dan Jones, Feb 6 2008;
> Those of you who run titanium valves, or have run them; are copper/berylium
> seats the only good way to go? I recently got some AFD heads, and want max
> durability (not a pure race engine). So, I am not up on the more modern
> thinking, and don't know if it will be a waste of time or equipment using
> the standard ductile iron intake seats and hardened exhaust seats with the
> racy valves. My guess is that the harder/lighter valves may tend to hurt
> the standard type seats, but I dunno.
> seats the only good way to go? I recently got some AFD heads, and want max
> durability (not a pure race engine). So, I am not up on the more modern
> thinking, and don't know if it will be a waste of time or equipment using
> the standard ductile iron intake seats and hardened exhaust seats with the
> racy valves. My guess is that the harder/lighter valves may tend to hurt
> the standard type seats, but I dunno.
Titanium needs a soft seat like cast iron or beryllium-copper. You do not want to use a hardened seat like stellite. My Dad's 1937 Chrysler Imperial has stellite seat and they are very hard, much harder than the induction-hardened cast iron seats used in most unleaded fuel heads. It was tough to do a valve job just on the Chysler using just stones,
though there are special cutters available. Certain cast iron seats may be compatible, others may not. It depends upon what they Rockwell test to be. My Ford Motorsort A3 high port heads have the original cast iron seats and guides which Ford Motorsport claim are compatible with titanium. If you run aleaded fuel, that will help. I discussed the issue of titanium valves briefly with a local circle track engine builder and he walked over to a drawer and pulled out a set of titanium valves that were razor sharp. He said it happenned after only a couple of weekends of racing. I'm not sure what he was running for seats but I'd guess there was some sort of dissimilar materials issue, though it could have also been a fuel issue.
Titanium tends to gall easily. To counter that, most titanium valves have moly impregnated stems, along with hardened steel tips. You don't want to lap titanium valves but a properly cut seat shouldn't need to be lapped, particularly if you're running an interference seat geometry. Here are the CV Products Titanium Valve Instructions:
"Steel tips or lash caps are recommended for all engine applications. Steel tipped valves should be faced off square removing approxiomately 0.002" of material. If lash caps are used, they should be flat parallel and free from tooling marks. Be sure the lash camp does not contact the retainer or valve keepers.
Valve face may be machined or ground as with other valves. When grinding, remove small amounts, 0.001" or less, and dress the wheel often to prevent loading.
Valve seats should be a soft material such as nodular iron, bronze, or beryllium-copper, all heat treated to Rc 30 or less.
Any standard valve guide material may be used with a minimum clearance of 0.001" intake and 0.0015" exhaust. Seals may be used, however some oil must be allowed to enter the guide.
All titanium used has been inspected and certified conforming to the Dept. of Defense Material Specification, Mil-T-9047 of latest issue."
Dan Jones
though there are special cutters available. Certain cast iron seats may be compatible, others may not. It depends upon what they Rockwell test to be. My Ford Motorsort A3 high port heads have the original cast iron seats and guides which Ford Motorsport claim are compatible with titanium. If you run aleaded fuel, that will help. I discussed the issue of titanium valves briefly with a local circle track engine builder and he walked over to a drawer and pulled out a set of titanium valves that were razor sharp. He said it happenned after only a couple of weekends of racing. I'm not sure what he was running for seats but I'd guess there was some sort of dissimilar materials issue, though it could have also been a fuel issue.
Titanium tends to gall easily. To counter that, most titanium valves have moly impregnated stems, along with hardened steel tips. You don't want to lap titanium valves but a properly cut seat shouldn't need to be lapped, particularly if you're running an interference seat geometry. Here are the CV Products Titanium Valve Instructions:
"Steel tips or lash caps are recommended for all engine applications. Steel tipped valves should be faced off square removing approxiomately 0.002" of material. If lash caps are used, they should be flat parallel and free from tooling marks. Be sure the lash camp does not contact the retainer or valve keepers.
Valve face may be machined or ground as with other valves. When grinding, remove small amounts, 0.001" or less, and dress the wheel often to prevent loading.
Valve seats should be a soft material such as nodular iron, bronze, or beryllium-copper, all heat treated to Rc 30 or less.
Any standard valve guide material may be used with a minimum clearance of 0.001" intake and 0.0015" exhaust. Seals may be used, however some oil must be allowed to enter the guide.
All titanium used has been inspected and certified conforming to the Dept. of Defense Material Specification, Mil-T-9047 of latest issue."
Dan Jones
Joe, Feb 6 2008;
Most people that use them are going all out , they use BeCu seats because on that type of engine the lobes are so aggresive that the BeCu acts as a shock absorber .BeCu does not eliminate bounce at 10k but it will limit it somewhat .
I do not know of anyone using the cross combo of ti valves and iron seats , most that go the ti route are building run what ya brung type engines with lobes at least as agressive as comps old hi-torque and going up from there !
The circle trackers are a different case . They use light valves so they can spin ~9000 for a long time without killing the valve springs .
sunnen sells all manner of cutters for their vgs machines that cut many angles simultaneously and create very little dust compared with grinding one angle at a time .
If I was spending this kind of money I'd hook up with somebody that has a big heavy accurate machine like a sunnen vgs, prefferably.
on feb 6 2008 I (Joe) wrote the above expeditiously in an attempt to settle some questions that I felt had their origins in drag race usage ,therefore the above was not intended to be comprehensive information on Ti valves and/or seat compatibility .
Ford did in fact run stellite seats and titanium valves in the 255 indy engine , I do not know how this combination of parts were mated .
I do not know of anyone using the cross combo of ti valves and iron seats , most that go the ti route are building run what ya brung type engines with lobes at least as agressive as comps old hi-torque and going up from there !
The circle trackers are a different case . They use light valves so they can spin ~9000 for a long time without killing the valve springs .
sunnen sells all manner of cutters for their vgs machines that cut many angles simultaneously and create very little dust compared with grinding one angle at a time .
If I was spending this kind of money I'd hook up with somebody that has a big heavy accurate machine like a sunnen vgs, prefferably.
on feb 6 2008 I (Joe) wrote the above expeditiously in an attempt to settle some questions that I felt had their origins in drag race usage ,therefore the above was not intended to be comprehensive information on Ti valves and/or seat compatibility .
Ford did in fact run stellite seats and titanium valves in the 255 indy engine , I do not know how this combination of parts were mated .
