1939 Flathead Powered Midget Racer

M

MarkFour

Junior Member
I am currently working to reassemble a 1939 midget/sprint/big car Racer for a customer and I've run into an issue. The car was running/driving 6 years ago but the previous owner blew the motor, removed it to have it rebuilt, then passed away. I knew the previous owner and had done some minor work on the car years ago. It was purchase by my current customer and brought back to me to reinstall the engine and get everything connected.

Engine block was supposedly too bad to rebuild and was junked by the machine shop after the previous owner never came back, but just about all of the other parts were still in the original owner's warehouse including edelbrock heads and 3 carb intake, flywheel with multiple patterns, accessories, etc. What wasn't still there was the clutch/pressure plate setup.

The trans was never removed from the car and is a 39 3speed with the throw out bearing still attached. 1 3/8" 10 spline shaft. PN 78-7006-4

The current owner had H&H build him a high HP motor using his head, accessories, and flywheel. He thinks its a 49. Its 24 studs per head and has a raised boss at the rear that could have been drilled for a full flow oil filter but wasn't. He then purchased a 10.5" clutch and PP from speedway and its bolt pattern seemed to line up with the most recent marks on the flywheel left by the old one and covers the newly machined surface. Its the pattern with 2 bolts a few inches apart in 3 locations on the FW.

I bolted the engine back into the car and before connecting everything tried the clutch, only to find it doesn't disengage. In neutral the car pushed easy. In gear it doesn't push at all with the clutch pedal completely bottomed. I disconnected the clutch rod and tried to push the arm directly and its the same. Looking through the inspection hole I can see that the TOB just barely starts to touch the fingers before its bottomed out. There's almost enough room between the fingers and TOB at rest that I can fit my middle finger tip. The fingers do not have the screws that some PPs have. The clutch is installed correctly with the springs/tower towards the PP and I am able to turn the engine by hand with no noises.

The original owner used to keep his cars well documented with a binder full of all the tech info and specs but it was unable to be located on this one.

Does anyone have any idea of what pressure plate/clutch I should be using or if there is a different problem I should be looking at?
 
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First of all, we should determine the type of block. He "said" he "thinks" it might be a '49.
Does it have the approximately 3" deep "half bell" at the back of the engine or not? In my experience, most midget racers had V8-60's, but some were converted to "Big Cars" at the end of their lives, so a regular V8 is possible.
 
The flywheel has several patterns drilled in it but the one used by the new PP lines up with the pattern that looked to be used most recently.


It does have half a bell housing as part of the block casting and as I said prior, 24 stud Edelbrock heads. the car itself is considered to be a "big car". I'm certain it's a full size bored and stroked flat head, supposedly around 180hp.
 
If it's got the "half bell", it should be pre-'49 engine with the odd front mounted distributor and center outlet cylinder heads.

Dos it have anything (numbers/letters) cast on the top of the half-bell?
 
It does have the center outlet heads, half bell and front mount dizzy. So it's surely a pre-49 with 24 stud heads. I'll see if there are any numbers on the bell when I get back to the shop, but it does have the raised casting area that could be drilled for a flow through oil filter.
 
Take a look at page #5 and beyond, "Engine Identification" in the Techno link in my signature.

Glenn
 
The Numbers on the bell appear to be F21611 but the last 2 digits are hard to read due to casting slag so I could be wrong on those. There is also the # 59 cast farther back on the bell.

My main question is are there different "length" pressure plates that have fingers closer to the throw out bearing?
 
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That appears to be more of a sprint car than midget. Midgets had 60hp engines and rear ends that would not take a 100hp and would not have had a heavy front spring.
 
jimTN said:
That appears to be more of a sprint car than midget. Midgets had 60hp engines and rear ends that would not take a 100hp and would not have had a heavy front spring.
Click to expand...

Racing is a constantly changing pastime, with ever-changing rules, popularity and tastes. In the fifties, midgets became less and less popular, probably because of the rising interest in the Indianapolis 500 and the ongoing desire for faster cars and more thrills. Many midgets were upgraded to what were called "Big Cars" by stretching the frame and replacing components. When I was vintage racing 20 or 30 years ago, several of the guys in my club had such cars with dual heritages.

'Sprint Cars", "Big Cars", and the old "Indy Roadsters" were all quite similar but were developed at different times for different reasons. Far be it for me to fully explain this as I was on the outside looking in (I was a "Modified Guy"). Back in those days, cars were very rarely built from scratch, at least by the established teams. If midgets were no longer popular, you took you car apart over the winter, changed a bunch of parts and ran a "Big Car" the next summer. My car is at least the third iteration of cars built by the Thurmer Bros. during the time they were active.
 
If I remember correctly... the 48 and older flywheel is thicker than the 49 and newer. Possibly it has an 8ba flywheel, and the pressure plate is further away from the throw-out bearing. Here is the comparison. 8ba on the right. Quick check, the 8ba flywheel pp mounting holes are drilled all the way through, 48 and older are blind holes.
 

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I'm thinking the ThrowOut bearing length varies as well. A longer throwout bearing might solve his problem.

Al Hook
 
Check the thickness of the disc. Some are thicker than spec. This will push the fingers closer to the flywheel.
 
The early V8s in the 59 series (1945 through 1948 for cars) need the early flywheel so that the starter will mesh up correctly to the starter ring. 8BA types are not the same. The other problem may be due to the 10.5 clutch if it's a later diaphragm type. They need throw out fingers that will reach back to the T/O bearing face. They are either curved back of they have extensions on them for that type of throw out bearing used on the 1 3/8"-10 spline input shaft.
 
The OP states the fingers do not have the adjustable tips like others. Leads me to believe he has the current foreign made Long style pp. If the OP would post pictures of said issue of existing pp, and flywheel to verify correct parts would help.
 
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