MTFCA Forum

A friend acquired this head. Neither he nor I know if this is an accessory for a T engine. Can anyone shed any information?

I believe that head is an Akron or something like that - it's valve action is operated by ball bearings in those tubes !

And yes, it's for a Model T.

Now that is a very interesting head. Anyone have anymore info on the design and use of one of these heads ?? I can visualize how it works, but "did it really work" ???

They have been discussed a couple times years past. I know I have seen one myself, about fifty years ago. Someone I did not know bought it and said he would try to run it, but I don't think he ever got that far. I had heard he did some work to get it nearly ready to install, but never heard beyond that.

They are a very interesting design, but a flawed design. In theory, the bearing balls should push smoothly through the tubes. In reality, the idea works nicely at low speeds for a very short time. In reality, at any speeds above a very slow idle, the balls bind and wear both themselves and the tubes that guide them. The friction and binding/bunching results in a resistance to rapid motion, and in effect a delay is forced to valve action, causing even heavier wear on the moving parts.
One report said that although the solid cam and lifters could force the valves to open (often resulting in breakage or more wear), The binding and resistance to motion at higher than idle speeds caused the valves to delay closing, or "float". Which in turn resulted incomplete gasses exchange and poor running.

One could take such a head, and modify it to run on common type push rods and rocker arms. However, they are such an unusual item, they really are worth more (not in dollars for the greedy among us) as a display piece to show some of what was.
A really neat item!

This is strictly from "memory" from reading, many years ago, about this overhead valve design and why it was considered a failure. Besides what Wayne noted concerning the resistance to motion from friction & binding, I remember that it was also determined that the combined weight of each tube full of steel balls caused a problem at higher speed that had to do with inertia and the fact that the solid column of those steel balls were too heavy to continually change direction fast enough to operate the valves without "valve float". As mentioned above however, that head certainly makes a fine "collectors piece as I'll bet they must be very, very rare! It certainly looks to be in perfect condition!

.....actually, I guess Wayne said the same thing, only said it better when he said,...."resistance to rapid motion"! Sorry Wayne,....I didn't read carefully enough!

No worries Harold S ! I thought all your comments were very good.

Here is the earlier discussion of it.
http://www.mtfca.com/discus/messages/331880/350261.html
It's nice to see a real one.
Thanks
Rich

Back in 1975 a good friend of my father-in-law's entered a brass era speedster in the Santa Clara model T speedster run that was equipped with an Akron head.

Years ago a guy from I think California brought one of those to some of the swap meet in the Portland Or area. Wanted too much for my budget even back then. Even back then thought it was neat but just a little too funky.

I think with that valve layout it would be very difficult to modify that head to use pushrods and rocker arms.

The Museum of American Speed has one of these heads on display. Check it out.

https://www.museumofamericanspeed.com/halakronhed.html

My friend who owns this Akron-Hed unit wishes to sell it.
If interested please contact him at 260-602-5362.
His name is John and he lives near Fort Wayne IN.
btw...John and I are grateful for the comments and education about this accessory head.
Many thanks.