cam to valve angle

Craig CT

Craig CT

Senior Member
A 1941 block has a valve angle of 101.5 degrees, 1946 and later have a valve angle of 100 degrees. Has anyone run an 8 C M cam with valves at 101.5 degrees and if so how did it work? Thanks in advance, Craig.
 
This has been done a thousand times with no noticeable differences. how many times has a Max #1 or an L-100 been run in an early block.
 
The valve angle changed around the center of the cam so the farther from the centerline you go the more radial distance would change. At the distance of the tip of the lobes from the centerline the radial change was probably not all that much. I know folks have swapped cams so they wouldn't have to use adapters when changing the distributor types so I'm sure it's been done just about any way you can imagine as long as there were cam bearings in there that made it work. With heavy duty performance stuff most serious folks check the cam timing with a degree wheel anyway.

Kerby
 
I have an 8ba style merc cam in my 33 eng,All I did was machine the nose off and make a little disc to drive the 33 dist, the eng goes great.Lawrie
 
The difference in valve timing is tiny, and Ford itself ignored it! Note that the 21A cam was designed for the early engine, and used without change up to 1948. I think that says it all. Virtually all aftermarket cams you are likely to find are also 21A based.
 
Bruce Lancaster said:
The difference in valve timing is tiny, and Ford itself ignored it! Note that the 21A cam was designed for the early engine, and used without change up to 1948. I think that says it all. Virtually all aftermarket cams you are likely to find are also 21A based.
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In your last sentence I think you meant 8ba.
After the war the big deal in cam advertising was that it was "corrected".
That meant it was ground properly indexed for the 46 and later blocks.
 
Hi Bruce; I read that it was better to match the cam grind to the valve angle and it didn't make alot of sense to me as long as the valve is still pointed at the center of the cam, that's why I posted. I also read that most reground cams were based on the early cams.
 
The 21A was the last version of the cams for direct drive distributor Fords, used '42-45 on early angle engines, '46-48 late angle engines...
Possibly Ford, certainly the main flathead parts suppliers in the day when there were commercial quantities of NOS, sold the 21A as the general replacement cam, requiring the drive button adapter for 3-bolt engines and new timing gears for some.
 
Bruce,is the 21a cam a good one to use in an early eng,I have one and an early steel cam,which would be better to use.
Thanks Lawrie
 
21A cam, assuming not reground, is the very tame '42-8 type. The steel one would be '32 or '33, and is somewhat more radical as stockers go.
 
Bruce Lancaster said:
The 21A was the last version of the cams for direct drive distributor Fords, used '42-45 on early angle engines, '46-48 late angle engines...
Possibly Ford, certainly the main flathead parts suppliers in the day when there were commercial quantities of NOS, sold the 21A as the general replacement cam, requiring the drive button adapter for 3-bolt engines and new timing gears for some.
Click to expand...

That is correct..The 46-48 cams (original or NOS) were wrong for the engine.
Ford decided it would be too expensive to change the tooling for the little improvment in performance..They corrected it in 49.
Aftermarket cam grinders corrected it right away and capitalized on the advertising.
 
Lawrie said:
Bruce,is the 21a cam a good one to use in an early eng,I have one and an early steel cam,which would be better to use.
Thanks Lawrie
Click to expand...
Hi Lawrie; The early cam intake opens at TDC. Tildon Technologies.com lists most of the flathead cams, Craig.
 
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