Dual Overhead Cam Flathead
- Thread starter deuce lover
- Start date
Bored&Stroked
Well-known member
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
Well-known member
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.
VeryTangled
Well-known member
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/threads/ansen.641438/page-3
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/threads/ansen.641438/page-3
Attachments
Last edited:
VeryTangled
Well-known member
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.
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.
Attachments
uncle buck
Well-known member
That was my thought also
Pete
BANNED
Note a very young Ed Iskenderian in the background of that pic.
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
Well-known member
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.
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.
Licensed to kill
Well-known member
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???.