69 Muncie M-20 Question

[Joe L.]

Re: 69 Muncie M-20 Question

Hey Gary,
Good to hear from you! I actually sold that car in favor of the convertible 427 I have now. That diff did great though! You know, I think the clutch may be a center force unit! I can't remember for sure, so I'll drop the bell housing cover and see. You may have hit the nail on the head. Do you have a recommendation on a good clutch that won't cause these problems?
We've finally gotten out of the WWII fighter restoration business for multiple reasons, most of all cost. I'm building an aerobatic experimental airplane now. Thanks for your help as always!
Brad

Brad-------


Your best bet is a GM flywheel (still available) + an NOS GM pressure plate assembly and disc. The latter are hard to find, though. Lacking the GM pressure plate and disc, I recommend a LUK unit. These can be purchased as a "RepSet" which includes pressure plate, disc, and release bearing. I ABSOLUTELY do not recommend the use of any "trick" aftermarket clutches for a Corvette. EVER.

Incidentally, as far as the "WWII fighter restoration" goes, it reminds me of an old friend of mine. He was an excellent pilot and owned an absolutely gorgeous Cessna 190. But, he got the "bug" for more power and speed. So, he sold the 190 (I was heartbroken) and purchased a T-6. The cost of operating that thing broke him and he sold it in less than a year. Then, he bought a homebuilt "Playboy". That proved to be the end of him. They picked up what was left of him and put it in a bag----a SMALL bag.

[Gary R.]

Re: 69 Muncie M-20 Question

Hey Gary,
Good to hear from you! I actually sold that car in favor of the convertible 427 I have now. That diff did great though! You know, I think the clutch may be a center force unit! I can't remember for sure, so I'll drop the bell housing cover and see. You may have hit the nail on the head. Do you have a recommendation on a good clutch that won't cause these problems?
We've finally gotten out of the WWII fighter restoration business for multiple reasons, most of all cost. I'm building an aerobatic experimental airplane now. Thanks for your help as always!
Brad

Ah too bad about the other 69, I know you put a lot of time into it. Too bad about the planes too, I saw your work on that Corsair in the mag you sent me, truly amazing and talented work.

Those CF clutches with the little weights on them sometime came off. The last 2 clutches I used were for my son's 75 and were both Hays setups. They bolted in and held up to some abuse at the track. He finally smoked it and went to another with a Steel bell housing. For normal driving it would be fine - providing the quality hasn't changed since we bought the last one about 8 years ago.

[Brad H.]

Re: 69 Muncie M-20 Question

Thanks Gary! I wish I could have kept both of them but it was just too much money to have tied up in both. I surely appreciate all your help with that car! I turned out very nicely and it was very tough to let it go.
Brad

[Brad H.]

Re: 69 Muncie M-20 Question

Joe,
Thanks for your insights about this clutch thing. May be a Centerforce clutch, shifter, bad adjustment, or worn transmission parts. I'll figure it out sooner or later. I/we all appreciate your continuous help diagnosing these cars! Your experience and knowledge are just invaluable not to mention your willingness to gratiously share it with the rest of us!
Thanks again,
Brad

[Mark E.]

Re: 69 Muncie M-20 Question

Lacking the GM pressure plate and disc, I recommend a LUK unit.

Amazon sells the LuK 04-020 Clutch Kit for my car for less than $90. That includes disc, plate, pilot and throw-out bearings, alignment tool and shipping. The listing says it's made in the USA too. Amazing.

One of the comments says the throw out bearing has plastic components though.

[Joe C.]

Re: 69 Muncie M-20 Question

If the bell-crank, upper, or lower clutch arms have ANY wear at the joints, this will cause a false free-play reading. In other words, some or MOST of your clutch free-play will actually be take-up of any slop in the linkage. If any of the holes are elongated, you should weld them up and re-drill them, otherwise buy all new linkage components. You are looking for ZERO "slop" in your linkage. I rebuilt my bellcrank and upper rod, replaced a worn lower rod, replaced a worn clevis pin at the clutch fork, run 1.25" free play and experience perfect operation. Actually, mine is set to quick-release, so I use the ratio of release throw length times 1.25, which is about .825" for free play.

I never liked the Centerforce flyweight gimmick. I have a RAM clutch and it works perfectly, including 7500 RPM powershifts.

There should be no need for an adjustable pivot ball unless your flywheel friction surface plane is different from that of a stock unit, as measured from the flywheel mounting flange on the crankshaft. I installed a steel flywheel and had to use an adjustable ball. If your iron flywheel is still in place it should be OK with the stock pivot ball, even if it has been surfaced, unless the thickness is less than the minimum stamped into the flywheel.

PS: A common problem is a cracked weld at the clutch pedal arm to hub joint. This causes the pedal to ride lower and prevents full range-of-motion. Another problem that I have dealt with.

[Brad H.]

Re: 69 Muncie M-20 Question

Great info Joe, Thanks!
Brad

[Brad H.]

Re: 69 Muncie M-20 Question

Joe,
So sorry to hear that! The last restoration we did at Vintage Fighters was a Navy SNJ-5 which was the sister to the AAC T-6. It is an every last rivet ground up restoration. We completed it several years ago after restoring 2 P-51 Mustangs, 2 F4U Corsairs, and a P-47D Thunderbolt. Unfortunately we eventually sold them all but the owner of our company couldn't bring himself to let the SNJ go. It sits in the hangar and gets polished but that's about it. Sounds a little like your 200,000 mile Corvette. It was a great business for over 20 years and I flew the airplanes a lot for Airshows, etc. I dearly loved the P-51 and will sorely miss flying that magnificent airplane! I have built several small experimental airplanes over the years so I have confidence in them. Very sad about your friend, though! Wish he had kept the 190. Reliable and beautiful airplane.
Again, thanks so much for all your help!
Brad

[Joe L.]

Re: 69 Muncie M-20 Question

I dearly loved the P-51 and will sorely miss flying that magnificent airplane! I have built several small experimental airplanes over the years so I have confidence in them. Very sad about your friend, though! Wish he had kept the 190. Reliable and beautiful airplane.
Again, thanks so much for all your help!
Brad

Brad------

...a P-51D, I expect? A fellow here at my home field (KHWD) has a P-51H which I think is one of the few in existence. I think that Mike is probably too aged to fly it anymore and I don't know if his son flies it, or not.

My friend's Cessna 190 was an absolutely gorgeous aircraft. I've never really been into taildraggers but that plane was just gorgeous---that big cantilever wing and radial engine were just beautiful. His was powered by a Continental engine which I believe was rather uncommon for 190's, most of which I think used Jacobs engines.

[Brad H.]

Re: 69 Muncie M-20 Question

Joe,
Yes, ours were both D models. The H model was really supposed to be awesome but you're right there are just 1 or 2 left operational. I have never actually seen one. I flew with the USAF Heritage Team since it's inception. A really cool book was done for us and I would love to send you one if you don't mind me having your address. Didn't know you were an airplane guy as well. Amazing how many Corvette folks are airplane folks as well. Sort of the same thing somehow.....

[Joe L.]

Re: 69 Muncie M-20 Question

Joe,
Yes, ours were both D models. The H model was really supposed to be awesome but you're right there are just 1 or 2 left operational. I have never actually seen one. I flew with the USAF Heritage Team since it's inception. A really cool book was done for us and I would love to send you one if you don't mind me having your address. Didn't know you were an airplane guy as well. Amazing how many Corvette folks are airplane folks as well. Sort of the same thing somehow.....

Brad-------

The H model that Mike owns has a kind of interesting story behind it as I've been told. It was, apparently, shipped to China towards the end of or after WW II. It was a brand new plane, shipped in pieces and mostly crated. Mike was able to purchase it quite a few years later, still unassembled. He and his crew assembled it so he had, essentially, a brand new P-51H at that time.

Thanks for the offer on the book; I'd love to have it; I'll e-mail you my address.