1940 Ford convertible sheriff's car
- Thread starter Kube
- Start date
Walt Dupont--Me.
Well-known member
Are those aluminum heads? Is the cam different than a regular 40merc? Walt
Kube
Super Moderator
Those are aluminum heads. Took me years to find them as they are quite rare. I had only glass beaded them.
The cam, etc. is identical to all 1940 Mercury engines. These heads were an additional "option" above and beyond the Mercury (engine) equipped Ford.
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Ralph Moore
Well-known member
Seems odd that a convertable would be used as a police car. I wonder what the reasoning was behind it. Does anyone know why?
1938 Coupe
Senior Member
So the wind can blow in your hair and maybe a little sun while your at it!
Kube
Super Moderator
Ralph, One must perhaps first understand the process required to obtain such a 1940 Ford built with a Mercury engine. There was NO "official" program for this in 1940. However, a specific process was in place. First, a letter of request and authorization had to be made on OFFICIAL stationary and given to the dealer. ONLY sheriff, police, fire officials could be considered for such a build. Then, the dealer had to request this special build to a specific person within the Ford Motor Co. with the aforementioned authorization.
Only then was this request approved or denied.
There were a total of 4182 Fords (various models) built in this way during the 1940 model run.
Why a convertible? I suspect this was possibly an abuse of position. In other words, the vehicle was approved under official request but perhaps intended for personal use. Of course that is merely my theory.
A couple of "side notes" might be relevant here.
One: NO 1939 Fords were built in this manner. In fact, the practice was strictly prohibited.
Two: In 1941 this practice became "official" and as such 1941 Fords equipped with the Mercury engine were not nearly as rare as the 1940 models.
I have owned a 1940 Deluxe coupe built in this manner and know of only one other coupe, currently quite a "basket case" built as such.
My convertible was "rescued" out of New York after MANY years of negotiations. Read: begging, pleading, bribing, etc
There were no other modifications performed upon these specially built vehicles. It was pretty much a factory "engine swap".
Those heads are really interesting. I cannot find mention in the SB or in the Ford/Merc or Ford(green book) parts book. The 59 series cast iron heads were the highest comp ratio given for v8s according to the SB. There is no doubt that HC heads would have made a good difference in the engines.
Old Redneck
Well-known member
Mike I would love to sit in your classroom to know a little of what you have done. Some are dreamers
Kube
Super Moderator
Jim, As you know, the parts book list ONLY the parts available for service replacement. My .02¢? I'd think any factory high compression heads had a very limited appeal. Way too limited to offer them as service parts.
These particular heads have a 7.1:1 ratio, quite a bit higher than the stock Mercury cylinder heads.
Bruce Lancaster
Member Emeritus
The call out is that the numbers are CAST, not stamped. My 81AS (there are variants with more defined number on face) heads have only "AS" on the front to distinguish them from the normal "A" cast 81A's, and full number cast on upper edge. These "Denver" heads were iron, in three variants...
They were discontinued BEFORE the cumulations...they are listed in some superseded bulletins and prewar parts lists only. Like many discontinued parts, they were never cataloged after the war.
I think the S marks then as parts counter only, not assembly line.
They were discontinued BEFORE the cumulations...they are listed in some superseded bulletins and prewar parts lists only. Like many discontinued parts, they were never cataloged after the war.
I think the S marks then as parts counter only, not assembly line.
Kube
Super Moderator
Bruce, Like you, I have seen variations of the 81AS heads. I have also seen variations of the "regular "81a" heads.
I have only seen one other 99AS head, corroded so bad as to be worthless, that was cast as mine are.
I think the "S" signifies "special". Perhaps I'll someday soon have the opportunity to research these at the Benson Ford Research Center.
By the way, one letter of two that came with this car clearly requests "high compression cylinder heads" to be installed at the factory. Unfortunately it does not spell out exactly what that meant but simply states "high compression cylinder heads".
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Kube
Super Moderator
Benson Ford Research Center. I actually have the break down of exactly how many 1940 Fords were built by month, model, engine, assembly plant, etc.
Kube
Super Moderator
I don't think I have a photo of the combustion chamber. They appeared very similar to any Ford cylinder head. In other words, no shape difference...
I am guessing the biggest difference between the Ford 81S heads and the Mercury 99AS heads would be the size of the chambers.
Bruce Lancaster
Member Emeritus
Yes, 81AS are the smallest chamber ones. The only 99AS heads listed in the bulletins are iron...so this is something unusual here!
ford38v8
Well-known member
Mike, I know of engine/transmission assembly serial number records by the day, but the trail ends there. Does your research follow those serial numbers farther?