finding exaust valves
finding exaust valves
(OP)
I race oval tracks in the northeast and am having
trouble locating 1 piece steel exaust valves for
a sm.blk. chevy. The rules state 1.5" oem or stock
replacement steel only, no stainless/swirl etc.
The problem is that the only valves I can find are
made from 2 pieces spin welded together. I have
had the valve heads break off and destroy 2 engines.
I only have 110# of seat pressure & less than .500"
lift. I don't want to build another grenade!!!
Any help would be greatly appreciated.
trouble locating 1 piece steel exaust valves for
a sm.blk. chevy. The rules state 1.5" oem or stock
replacement steel only, no stainless/swirl etc.
The problem is that the only valves I can find are
made from 2 pieces spin welded together. I have
had the valve heads break off and destroy 2 engines.
I only have 110# of seat pressure & less than .500"
lift. I don't want to build another grenade!!!
Any help would be greatly appreciated.





RE: finding exaust valves
RE: finding exaust valves
hydraulic only, no Rhodes etc... lifters.
I don't know the seating velocity is but it
can't be very high compared to other cams.
With this lift, a base circle of 1.250, a 2bbl
carb., & r.p.m. of 5500 max. I can only attribute
the failure to the valve. It's a 350 chev. 8.9:1
max per. rules. I run it 2 percent rich & max
water temp. is 195 deg.f. The plugs look great
(nice&tan), & so does the exaust system. I just
need a 1pc. valve that will comply with the rules.
RE: finding exaust valves
Seating at 110# is vertually stock and @.500 pressure sould be something like 275# or so. You should not have problems with OEM valves, except valve float if you overrev!
Rod
RE: finding exaust valves
there please help? Thanks in advance.
RE: finding exaust valves
RE: finding exaust valves
I don't have the money, time or, talent to indulge myself with NEW parts when GOOD used stuff is available!!!(When you deal with 'vintage' engines, it is sometimes difficult to find 'new' that are up to standards.)
Rod
PS---I ran the crap out of SB Chevys and never dropped a valve!!! NHRA records way back when.
RE: finding exaust valves
RE: finding exaust valves
bouncing going on. We've run the same seat
press. at other tracks at higher r.p.m.
with stainless valves & had zero problems.
'Mater of fact I'd like to get to 100#s for
this track. Thanks for the link, it didn't
work but I did a search & found the company.
I'd like to find the parts here in the U.S.
but maybe I'll have to contact them in the
U.K. By the way, 2 different engines & 2
different mfgs. of valves were used.
RE: finding exaust valves
RE: finding exaust valves
Well, so much for the 'experts', eh? I think at this point, I would be taking everything apart and starting from square one. If this was MY engine, at this point, I would be assuming the problem was 'builder generated'.
Rod
RE: finding exaust valves
related I spent a lot of time sifting through
the mangeled parts & found nothing. I ALLWAYS
degree the cam & ck piston to valve clearance.
This is a free spining engine @ up to .520 lift.
If the timing chain broke there wouldn't be any
damage. Still looking for the answers I went
back to the pile of junk and think Iv'e found
something. 3 of the hydraulic lifters don't
leak down very easily. The same set was used
in both engines! They were supplied with the cam.
I didn't notice anything while setting the lash,
so maybe it is my fault. I will however use 1pc
valves from now on. (still looking)
Thanks all for your help.
This is a great site.
RE: finding exaust valves
www.manleyperformance.com
talk to the factory and see if they can help
RE: finding exaust valves