Valve Length
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Junior Member
Joined: Jun 2001
Posts: 11
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From: Kaneohe , Hawaii
Valve Length
Anyone know the standard length of a SB Chevy valve? Is it 4.855? I have a pair of aftermarket aluminum heads for my buick in need of some exhaust valves and I am pretty sure it uses SB chevy SS valves. The head maker said the valves are 1.60 11/32 4.855
TIA
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Got Boost ???
87 Turbo Regal
PTE-51 , PTE FMIC , THDP , 009s , PMAC Trans.
3000 stall , 340 walbro
91 Camaro Z-28 , 350 TPI,Police Pkg.
turbovsix@hotmail.com
TIA
------------------
Got Boost ???
87 Turbo Regal
PTE-51 , PTE FMIC , THDP , 009s , PMAC Trans.
3000 stall , 340 walbro
91 Camaro Z-28 , 350 TPI,Police Pkg.
turbovsix@hotmail.com
Supreme Member
Joined: Jul 1999
Posts: 18,457
Likes: 16
From: Loveland, OH, US
Car: 4
Engine: 6
Transmission: 5
4.911"...
They should work fine in place of 4.855", you would probably want .050" longer push rods than stock, and maybe an extra .050" or .060" shim under the valve springs.
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"So many Mustangs, so little time..."
ICON Motorsports
They should work fine in place of 4.855", you would probably want .050" longer push rods than stock, and maybe an extra .050" or .060" shim under the valve springs.
------------------
"So many Mustangs, so little time..."
ICON Motorsports
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Joined: Jan 2000
Posts: 19,651
Likes: 309
Turbo,
RB is corect (again, as usual). The length isn't that critical if you are going longer, unless you are using shafted rockers. Some of us "old farts" used to cheat by using 11/32" BBC and some Ford 351 valves in SBC heads to allow the use of stock length push rods and stock springs on a higher lift cam. (Of course, the BBC and 351 valves were available in a lot larger sizes than the stock SBC valves.)
As long as you are not going shorter, you might not even need to shim the springs if you are using decent aftermarket springs and can maintain adequate seat pressure on the closed valve (over 90 pounds on a performance engine).
And be careful about the potential differences between intake and exhaust valve lengths, just in case.
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Later,
Vader
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If you want to beat the World, it might reach up and pull you down...
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RB is corect (again, as usual). The length isn't that critical if you are going longer, unless you are using shafted rockers. Some of us "old farts" used to cheat by using 11/32" BBC and some Ford 351 valves in SBC heads to allow the use of stock length push rods and stock springs on a higher lift cam. (Of course, the BBC and 351 valves were available in a lot larger sizes than the stock SBC valves.)
As long as you are not going shorter, you might not even need to shim the springs if you are using decent aftermarket springs and can maintain adequate seat pressure on the closed valve (over 90 pounds on a performance engine).
And be careful about the potential differences between intake and exhaust valve lengths, just in case.
------------------
Later,
Vader
------------------
If you want to beat the World, it might reach up and pull you down...
Adobe Acrobat Reader
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