Dual Overhead Cam Flathead

[deuce lover]

Got this pic from a friend. Anyone know about this?

[V8COOPMAN]

That almost has to be something out of "Speedy Bill's" (Speedway Motors) huge collection of exotic flathead stuff. There were a few folks with an open-minded imagination (and the means to pull it off) even back in the day. DD

[Bored&Stroked]

Those are probably some variant of the Davie's (sp?) heads that I believe were originally designed for a car for the Indy 500 in the early 50's. The originals were driven by vertical drive shafts off the crank with some sophisticated bevel gears and other such fun. While I'd love to have a set, would love to see a more modern design - based off of the Ford 4.6 DOHC motor.

[Henry Floored]

Interesting that they drive the camshaft belts off the cam stub and not directly off the crankshaft like they do in most OHC designs today.

[outlaw]

I wonder about where the distributer & water pumps are.

[RalphM]

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Bob Estes special, 1951. Described as unsuccessful in Roger Huntington’s 1951 book.


Still pretty ingenious, and cool looking!

[itsa52]

1:1 that way

[VeryTangled]

Great thread! I'm wondering what the heck the combustion chamber looks like?

Editing: It looks like those are two different overhead conversions. One belt, one shaft driven. The second one is referenced here by Rockerhead, with a photo (front left)... https://www.jalopyjournal.com/forum/....641438/page-3

[oj]

I recall similar engines developed for the Sherman tank, dual overhead cam. I saw one on ebay years ago, it wasn't complete and salty.

[VeryTangled]

Just found some more info here... Hemi combustion chambers, to answer my earlier query.

http://www.roadsters.com/flathead/#Davis

The text says...
The Davis heads were the work of Joe Davis, a talented pattern maker. They were cast in 1948. The first sets had a shaft drive mounted on the front of each head for the cams.

Joe Davis used to drive around Los Angeles in a 1932 Ford pickup with one of these engines sticking out of both sides of the engine compartment.

Bob Estes, a Lincoln/Mercury dealer, bought the engine from Davis and ran it in his Indy car in 1952. It did not qualify due to engine trouble, with water coming out of the exhaust. Dale Estes, Bob's son, still has the car, with the engine now having a gear drive.

In an article by Tom Senter in the May, 1971 issue of Rod & Custom, on page 29 there is a picture of an engine with these heads. The caption reads, "Rarest of them all. The Davies DOHC making a 1948 show. Meticulous hemi featured flawless castings, four cams driven off tower shafts. Raced at Indy in '52 by current owner Bob Estes."

Joe Davis made ten sets of these heads. The engine you see here has one of the four sets that are known to exist today. It belongs to John, a friend of mine in California.

When the project has progressed, I'll add some pictures of the car that this engine is going in.

[uncle buck]

Originally Posted by outlaw

I wonder about where the distributer & water pumps are.

That was my thought also

[Mart]

I'm thinking the use of the toothed belts is a modern (ish) attempt to get those heads working. That sort of belt drive wouldn't have been available when the heads were cast. The shaft drive in the pic looks really well engineered.

Mart.

[Pete]

Originally Posted by VeryTangled

Great thread! I'm wondering what the heck the combustion chamber looks like?

Editing: It looks like those are two different overhead conversions. One belt, one shaft driven. The second one is referenced here by Rockerhead, with a photo (front left)... https://www.jalopyjournal.com/forum/....641438/page-3

Note a very young Ed Iskenderian in the background of that pic.

[Tim Ayers]

Isn’t there a Gentleman somewhere down South that is doing all sorts of neat things with flathead Fords and Hudson’s? I think I recall a double OHC setup in his picture gallery.

[Fordors]

Originally Posted by Tim Ayers

Isn’t there a Gentleman somewhere down South that is doing all sorts of neat things with flathead Fords and Hudson’s? I think I recall a double OHC setup in his picture gallery.

I think you are referring to Uncommon Engineering in the Indianapolis area, he does a lot of one off stuff for flatheads and Hudsons. He was also building a clone of the Novi V8 too.

[GB SISSON]

Originally Posted by Pete

Note a very young Ed Iskenderian in the background of that pic.

Without the cigar.... So, the camshaft's lobes act directly on the valve stems, no rockers? My ohc toyota station wagon in the 70's had rockers.

[40 Deluxe]

Originally Posted by oj

I recall similar engines developed for the Sherman tank, dual overhead cam. I saw one on ebay years ago, it wasn't complete and salty.

Actually, the Sherman tank engine was NOT similar, in any way, shape, or form! That thing was huge, maybe around 1,000 cubic inches. It was originally designed to be a V12 aircraft engine but when that didn't pan out, it was reduced to a V8. You can find lots of info on the web, including YouTube.

[tubman]

Oxymoron?

[Licensed to kill]

SO.....I'm having some difficulty wrapping my head around both HOW this works and WHY you would want it. First, how does it work??. there are no valves in the block for the bottom cam to access so how does that work?? and even with the upper cam being positioned along the row of valves, since the valves open the other way (up for open, down for closed), are they opened by spring pressure and closed by the cam lobes??? I would sure like to see it with the heads off. As to why, the flathead already works in an upside down OHC concept where the the cam works directly on the valves (through a lifter) without pushrods and rockers so what would be the point (advantage) of putting the cam(s) on top???.

[Mart]

They work like any other dohc engine. Most modern engines use this format.