Valve choices

[CNC-Dude]

How expensive do you think it is to cut down the LS valves, backcut them and have them trim the tips to length...? Plus you'll have to replace the guides to reduce the valve stems that much smaller than the OEM Slant size....Since you'd have to do that to use a 7MM valve as well, you might as well get all the benefits you can for not much more money, if any. Somebody on .org found a factory 7MM valve awhile back that would work. I'll try to find that thread and see what they used....Also, including valves with a 5/16" stem will open up your selection even more!

 

[MOPAROFFICIAL]

3/8 to 8mm, world of diff.
8 to 7? Splitting hairs.
Am I still interested if its cost effective and readily available, sure. Thanks.

 

[CNC-Dude]

No problem, many Chevy race valves are 5/16" and could open a lot of other options too if that helps....

 

[CNC-Dude]

I found the thread over on .org, and the valves mentioned were from the 4.6L/5.4L Ford engines and also the 3.8L Ford Ranger. These have the 7MM valve stems....

 

[Killer6]

3/8 to 8mm, world of diff.
8 to 7? Splitting hairs.
Am I still interested if its cost effective and readily available, sure. Thanks.

Heres the Ranger 4-banger valve;

V01743

Ford / Mazda Engine Valve Length Stem Diamter Head Diamter 4.787 .2750 1.735

ussealparts.com

7mm, lighter still, and a bit more precious pocket volume...

 

[Killer6]

3/8 to 8mm, world of diff.
8 to 7? Splitting hairs.
Am I still interested if its cost effective and readily available, sure. Thanks.

Actually doing the math, the 8mm is ~28.5% less stem mass & pocket volume displaced than a 3/8" stem, 7mm is ~55% less...more than a hair..

 

[CNC-Dude]

Yeah, 7MM is the way to go to get the maximum pocket volume...and wont really cost any more to do it.

 

[Killer6]

I think the stem diameter makes more difference than might be expected. I know Justin's done some playin around with it and come up with some interesting numbers. I guess wanting to get the most flow you'd certainly look into it.

I was bugged about My post on the 3.3/3.8L valves, looked back at it, correction...
the '01-'10 valves are 7mm stems, 1.89"/1.40", & 4.98"/5.04" OAL.
I know the LS valve reference was for the endless SB thread, but anyways......

 

[RustyRatRod]

I was bugged about My post on the 3.3/3.8L valves, looked back at it, correction...
the '01-'10 valves are 7mm stems, 1.89"/1.40", & 4.98"/5.04" OAL.
I know the LS valve reference was for the endless SB thread, but anyways......

Are those valves a length that could work with the slant 6?

 

[Killer6]

Are those valves a length that could work with the slant 6?

If You've got SB valves in already, yes, lol! Otherwise, about .300" too long, so..
The Toyota Land Cruiser valves I want to use are 4.91"/4.94" OAL, that & some spring seat machining should be good for the 26918 Comp behives.

 

[CNC-Dude]

Si has a lot of 7MM blanks so you can make your own or they can make them for you specific to the valve length you want...They also have bronze guides for them too....