one better than the other and why?
was reading a discussion on some import heads, couldnt figure out if it was fact, opinion or regurgitated bs.
powdered metal vs ductile iron seats
Moderator: Team
Re: powdered metal vs ductile iron seats
Ductile iron is not necessarily any more wear resistant than cast iron, just well....more ductile. Should be nice to work with but not highly durable.
if they will hold up good enough or not, It very much depends on the application.
Sintered seats are made of metal powder kind of "Forged" into a solid piece.
They usually machine VERY nicely and yet can be highly wear resistant, a combination of PROS not possible with other types.
There is some concern that since the material is not 100% solid, they may be more prone to shrink with many heat cycles, they may be also more prone to chip. Tho people who LIKE them and use them and would say that such problems don't happen with HIGh quality sintered seats, and that is surely true to a degree.
Although IMO, "Killer bee" valve seats would not have been developed unless there was at least some small problem to solve.
There are also a third category of seats often cast, stainless and semi-stainless alloys with high chrome or nickel content, which are very strong and solid, and reasonably priced.
The main CON would be they are difficult to machine.
if they will hold up good enough or not, It very much depends on the application.
Sintered seats are made of metal powder kind of "Forged" into a solid piece.
They usually machine VERY nicely and yet can be highly wear resistant, a combination of PROS not possible with other types.
There is some concern that since the material is not 100% solid, they may be more prone to shrink with many heat cycles, they may be also more prone to chip. Tho people who LIKE them and use them and would say that such problems don't happen with HIGh quality sintered seats, and that is surely true to a degree.
Although IMO, "Killer bee" valve seats would not have been developed unless there was at least some small problem to solve.
There are also a third category of seats often cast, stainless and semi-stainless alloys with high chrome or nickel content, which are very strong and solid, and reasonably priced.
The main CON would be they are difficult to machine.
Re: powdered metal vs ductile iron seats
Just curious...lots of import castings use these, now at least 1 us mfr is starting to also. Maybe they are fine?
Some have said they are ok til you start running stiff solid rollers. I have no idea
Some have said they are ok til you start running stiff solid rollers. I have no idea
Re: powdered metal vs ductile iron seats
Valve seat material you want to use has to do with the fuel used, what the valve is made of, how hot the valve gets, and how hot the head gets, and what kind of ah.... atmosphere it lives in....(how lean it runs or if it's a diesel, egt, ect).
it doesn't have anything to do with being imported, tho a lot of imports are small four valve heads.
All else equal, two small valves will run a lot cooler than one big one.
it doesn't have anything to do with being imported, tho a lot of imports are small four valve heads.
All else equal, two small valves will run a lot cooler than one big one.