V8 flathead valve info...

hardtimes

hardtimes

Well-known member
Is the diameter of the valves 15/8" ? Are intake/exhaust same diameter ?

I'm talking the new straight stem stainless steel type.
 
I used Chevy 1.6" exhaust valves for both intake and exhaust for my '49 8BA. Maybe my mind's trying to justify that choice, but the engine really seems to like that combination!
 
Notadufus said:
I used Chevy 1.6" exhaust valves for both intake and exhaust for my '49 8BA. Maybe my mind's trying to justify that choice, but the engine really seems to like that combination!
Click to expand...

Yeah, well I located a V8 valve in my junk. 1.5 inch diam..
Tried it in the head.....and it fell right thru hole:eek: !
Maybe misunderstood some advice given, on what would fit ! This is antique head.
All the valve holes seem the same...+/- 15/8 inch... Sooo, either they came that way or were enlarged slightly. Oh well, off to check with Isky for some parts I guess.
Thanks for all your help/input.
 
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You have more information available than those of us that are trying to help.

You know more about the background of that motor. We can only assume it is stock unless you tell us something different.

Swapping to Chevy 1.6" valves is a popular modification. Maybe someone did this in the past? Or something bigger still?

Also you say head. Presumably you mean block. If you do really mean head then I haven't got a clue.

Mart.
 
Mart said:
You have more information available than those of us that are trying to help.

You know more about the background of that motor. We can only assume it is stock unless you tell us something different.

Swapping to Chevy 1.6" valves is a popular modification. Maybe someone did this in the past? Or something bigger still?

Also you say head. Presumably you mean block. If you do really mean head then I haven't got a clue.

Mart.
Click to expand...

Hey Mart thanks. I'll look at the 1.6 :)! Just might be the one.
I've got a 4-port OHV head...circa '32/'33. No valve/springs/keepers. The old timer either did not have them , or they got lost in he shuffle. He's gone. I'm trying to finish what he wanted to do...I.e.-put it on a '32 B.
 
Ok, we're talking a 4 cyl. Completely out of my area. The 1.6 quoted was the common fitment of Chevy valves for flathead V8s. For an ohv conversion you will need more specialised info. there are people out there who know this stuff, but I don't know who.

Unless someone does chime in here, I'd suggest a post on the hamb giving as much info as possible, especially in the post title line. You could also try the model A section here, but I don't know if they cater to ohv conversions.

Good luck with it. though, it does sound interesting.

If you know the valve head diameter, the stem diameter and the length you should be able to find something that can be made to work. Most valve manufacturers have catalogues showing all the dimensions.

Mart.
 
For a slightly O/S Flathead valve you also have an option of using an exhaust valve from a 240"/300" Ford "6", it measure 1.560" and doesn't affect the installed spring hgt.

It is exactly the same length as the Flathead's at 4.818" (nominal) and has same keeper-groove location!

Thanks, Gary in N.Y.

P.S. Wishing all here a safe and "Happy Holiday" season!! "Merry Christmas and Happy New Year"!
 
On my next build I have to use the chevy longer valve, due to the excessive valve lift. The oversize intake valve prevents me from using a 1.6 valve, but a 2.560 might work if it had a longer stem. I had a book at the old shop that had every valve ever made it I think. Must have been tossed when we moved
 
I have been using Jessie at Manley for all my valves, customs are not that much more money these days and he will make them any length and diameter you want.
You can call him direct at Manley New Jersey


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