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Headwork, valves and seats

Started by ricochet, May 07, 2009, 06:33:29 AM

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ricochet

Hello.  Got a couple knucklehead castings I'm working over to install on a 86" stroker.  Both required some work, a little welding, and thread repair.  That's all gone well and done.  Now noticed that one intake seat has a larger ID than the other.  This one is @ 1.700 ID x 1.875 OD for the installed seat.  The other is stock like @ 1.562 x 1.875.  I think there are two altenatives to have them match.  Find 1/8 OS intake valves and open up the stock seat to match the OS seat.  Or, pull the OS seat and intall stock seat and stock valves.  Assuming I can locate OS intake valves, would it be better to go that route to get more flow seeing it's a stroker and using a heartier Leineweber #2 cam?  I have seen OS intakes at 1.812 from Flo Headworks web site.  That's 1.812 valve over a 1.700 seat so does that leave enough contact area for the seat?

Any ideas where to find OS intake valves?  I've looked at Manleyand Rowe already plus Flo which I have to check out. 

Any advise or comments are appreciated.

ricochet

chris haynes

Use Shovelhead or Chevrolet small block valves and cut down the stem.
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ricochet

If I did that wouldn't I have problems with the stem tips mushrooming?  One of the real big valves I took out of another head was like that big time.  Or is it easy enough to install lash caps there?

The more I look at it seems that just installing a 1.875 valves in each head and opening up the seat on the smaller one would work.  If the opened up the seat in the head with the bigger valve worked it should be ok for both.  Makes the seat OD the same as the valve OD but the valve is still seated on the hardened seat.  And I got to think that by not disturbing the seats there's some value in that.

ricochet

jimlibo

Kibblewhite Precision Machine makes a 1.940" for that, OAL is 3.590". Their part number is 20-20414.

ricochet

I looked more closely at the intake valve that came out of that head with the opened up seat and it turns out to be an 1/8 oversixed HD Exhaust valve.  Wonder how it worked out with the longer stock stem as an intake?

ricochet

ricochet

FYI,   I ended up buying the 1.94 oversize intake valves fro S & S for the knuckle and they ended up being nice looking KPMI valves anyhow at a reasonable price.  KPMI was etched into the valve stem.

ricochet