VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 Some '36 questions

Hi,

Can someone please tell me what the diameter of the flywheel on a 1936 standard engine. The unit I have came minus the flywheel and I'm thinking I might need to adapt one from something else but I haven't been able to find a reference to the diameter.

Also, what thread is needed for the bolts that attach the bellhousing to the engine? I don't have any that fit in my bolt pile.

Thanks for any help.

Glen.

the flywheel fit 1935 and 1936 all and had 133 teeth and book says 13 5/16" gear diameter. The way the disc was recessed into the fly wheel I doubt if any thing else woulld work.

I measured and 13-5/16 is correct for the flywheel. The bolts for the bellhousing to the engine are 7/16 - 14

What "book" are you referring to? I have the 1935/1936 Chevrolet Repair Manual and can't seem to find that reference. Perhaps I'm looking too hard.

Since I'm lacking the entire flywheel/clutch-plate/pressure-plate assembly, I was hoping that I could perhaps use a complete assembly from something else that is more easily obtainable here… such as a Holden. I believe the 202 Holden/3 speed clutch-plate has 10 splines, so might just fit the chev input shaft. I haven't got one to try so will need to investigate that. I would need to adapt the flywheel though as they have 6 holes instead of 4.

Thanks for your help.

Glen.

Thanks for that.

Glen.

Book was a parts book.

Glen,

I have learned from Chev Nut's posts that prior to 1937 the clutches were hair trigger, ie. lacking a smooth and progressive engagement. My '36 PU is like that and while I'm used to it from driving it for decades I wish it weren't like that.

If I knew in the early 1970s when I assembled the engine what I know now I would adapt in a modern pressure plate with a smooth engagement. The best example of that I have ever felt is my 1971 Dodge van that I bought new and still have. Its clutch engagement is truly "silky" no matter the load placed on it, for example starting from a dead stop on a steep hill hooked up to a heavy trailer is no sweat.

I have found many parts interchanges for my '36 by looking through catalogs that have pictures and dimensions. There is no reason that I can think of to not use non-original parts if they are not visible and will make an improvement.

The 1937 Chevrolet still used the crappy old style clutch.

Thanks brino, that gives me some encouragement to continue searching for a more modern alternative. The project will undoubtedly be a long one and it is going to be a hot rod, so I really don't care at all about the "correctness" of the parts I use as long as they work. If they work better than original, that's a bonus. Since the entire flywheel, clucth-plate, pressure-plate, starter assembly is missing, I figured I'll just find something that works. I do have the bellhousing, so it's a matter of getting parts that fit within that and all mesh together.

To give an idea of what I am doing, the only '36 chev parts will be the basic engine, gearbox, front and rear ends, and wheels. I will most likely use quarter elliptic springs on all four corners attached to a chassis made from 100x50x3 RHS steel.

I've got a pair of solex 44pa1 carbs and will make an intake for them since there was no intake with the engine. It was also missing the exhaust manifold so I will make that too. There was no distributor, so I recently got one of those but it has no cap, rotor and the vacuum part is missing. The gearbox had a broken 1st/reverse gear which has now been replaced. It's missing the gearstick and some bits around the top of the 'box that holds the stick in. Lots to do.

A 1938 Hillman grille that I've got will go on the front with a home made bonnet (hood) going back to a home made roadster body. If I can find an original roadster body of some description locally, I'll use it... but I'm not holding my breath on that. I'm aiming for an overall look of a roadster that might have been seen on the dry lakes in the early 40's, but I'm not trying to be authentic.

Thanks again for the help.

Glen.

"To give an idea of what I am doing, the only '36 chev parts will be the basic engine, gearbox, front and rear ends, and wheels. I will most likely use quarter elliptic springs on all four corners attached to a chassis made from 100x50x3 RHS steel."

Glen,

That sounds like a very cool project. Since you're not seeking originality why not use a good transmission like a 5-speed out of an S-10 pickup. Guys who have used them in Ford flathead powered hot rods tell me they totally transform the cars. The '32-'36 Chevy transmissions, even the synchronized versions, are stone age in design and even when set up perfectly don't work very well, especially at higher RPM.

Also the '36 rear axle is of spiral bevel design and only the original 4.11 gears fit, definitely the wrong ratio for a lakes roadster. Why not use a '37 Chevy car rear end if you insist on staying with Chevy parts? It is of hypoid design and will accept a variety of gear ratios including the 1950-54 Chevy car 3.55 gear set. I have that gear set in my '36 PU and it is a perfect match to the stock '36 engine. Even more flexibility would result from using a small, light weight open drive rear end like a Ford 8 inch or one from a FWD S-10.

If you can find some, Weber side draft carbs would look very cool and would be easy to fabricate a manifold for because of the side draft layout. A pair of those are on my wife's Mercedes 190SL and although the rest of the car is a pig (don't tell her I said that) the carbs exude "race".

"The 1937 Chevrolet still used the crappy old style clutch.

Gene,

Do you know of an improved pressure plate of the correct diameter to fit the '36 flywheel? It seems that the cars/pickups had different size clutches than the 1 1/2 ton trucks so there may be room for a large clutch. Frosting on the cake would be not having to redrill the flywheel for the alternative pressure plate. Getting that done in a rural area like the one I live in would be tough. Here measurements are made with yardsticks, not micrometers and dial indicators.

I recall from reading Hot Rod magazine as a teenager in the early 1960s that flywheel friction surfaces are not ground flat, but rather at a 1/4 degree slightly conical surface to facilitate progressive, non-grabby engagement.

The 1937 and 1938 flywheels and pressure plates are as different as cats and dogs.
What you can do with a 1937 is replace the transmission front bearing retainer (to have a place to support the ball bearing T.O bearing) with a 1938 and install a 1938 (and up) clutch assembly and flywheel.

There are very good break=downs of the two style clutches in the 1938 and up parts books and in the 1938 engineering manual.

Gene,

What are the options for improving the pre-37 clutch assembly? I know from long experience with my '36 PU that the clutch is, and always has been, hair trigger. It can be annoying when starting up a hill from a stop when there is someone right on my rear bumper (usually a kid or a yuppie texting on his/her "smart phone"). Otherwise it's not a problem because I'm used to it.

Is the only answer to avoid kids and yuppies?

Maybe I should just roll back and let my rear bumper impact the hood badge on his/her BMW/Mercedes/Lexus/other Statusmobile.

Perhaps regrinding the flywheel friction surface to a 1/4 degree taper would help, but finding that kind of precision grinding in "Podunk" where I live would probably be a lost cause.

Thanks for all the input guys… good food for thought.

If I go down the path of a 5-speed, then I'd certainly change the rear end to open drive. I'm currently just working with what I have until funds permit those other improvements. When I build the chassis, I'll make sure I plan ahead and build in such a way that things can be easily changed. In the meantime, I'll just continue planning, researching, thinking, and see how things fall into place… they usually do at some point.

I'm now thinking my main focus should be getting a rolling chassis so I can move it around and plan component placements.

Glen.