A couple of years ago I purchased this fly wheel really cheap. It is for an early Olds Rocket and is obviously new and never been used. It was also obviously stored under terrible conditions that resulted in the badly corroded spots. I initially was going to use this to put a '51 Olds Rocket into my vintage dirt car to replace the early hemi that is currently in it. (The car originally ran an early Rocket back in it's glory days.) The car runs an "in/out box" so it does not use a clutch; we just bolt a disc and pressure plate on the fly wheel with no linkage and run it. At the track, the car is push-started and away we go. It is nice, however, to have a starter for tuning it between race events, especially if you are by yourself. Plans may be changing, and I an thinking of using the Olds in the "Tub" I am building. That car will definitely need a clutch and I am wondering if I might be able to use this, maybe after balancing. The car will be under 2000 pounds and the Olds will be pretty mild. Perhaps the huge pits can be cleaned out and tig-welded with Phosphor Bronze, and resurfaced. I know it's not recommended, but have you tried to find an aftermarket flywheel for an early Olds that is not completely shot?
Can't really tell how deep those pits are. Talk to a machine shop and see about having it resurfaced.
heck-as mild as he's talking-just surface it and figure you have about 99% of the friction surface available!
The pits are between 1/16" and 1/8" deep. If you look close enough, you can see that the pits go through to the aluminum. Resurfacing is not going to help at all. The rest of the surface is virgin.
Those "pits" aren't the only areas where corrosion between the steel and aluminum has compromised the connection between the two metals. Do the safe thing and throw it in the scrap pile.
Yes, looks like cats or vermin pissed on it for a while. That piss is a destroyer. Does,nt evaporate like a little bit of water would, just keeps biting in.
I bought some aluminum heads once with a little of that white crust on the mating surface. Thought it couldn’t be too bad at the time. When they were cleaned off by sand blasting, some of the pits were a quarter inch deep. I would think you’d like to know what you really have there, before you put your feet next to it.
If you value your toes, no, I wouldn’t run it. Why do so many guys want to run a vintage engine, yet skip out on the safety bits? I rather have the warm feeling in my belly that my feet and legs were safe, than that warm feeling as you bleed out with that $200 in your pocket you didn’t spend on the flywheel…
Check and see if a clutch rebuilder can put a new insert in the flywheel. Once its removed you can decide if its corroded badly enough to affect balance or intergrity. I doubt a few small places in the aluminum will hurt anything and the Olds is not going to be turning really high rpms........is it?
years ago I sent one like that to McLeod, they built me a new steel faced billet aluminum flywheel to match using my ring gear.
My main concern would be the possibility of more of that spray-on friction surface coming loose and getting between the flywheel and the clutch disc. All of a sudden you'd have a clutch that won't release which could prove to be a bit sticky in traffic. Then there's the general advisability of running an aluminum flywheel on a street car. While the 'instant revs' it offers adds to the 'fun factor', it's lack of 'energy storage' makes getting away from a stop harder. They don't dampen vibration under load worth a damn either, which while acceptable on a race car, isn't very desirable for a driver. I ran one on a big-inch FE Ford in my youth. Never again....
@tubman seen one at the swapmeet the other day a bit pricey but like you said hard to find. He’s a local guy if that one doesn’t work out
Only way I'd chance it even after a clean-up is inside a blowproof steel safety bellhousing and a block plate. No way with an aluminum bell or a cast iron either. If I had a steel bell, I'd give it a go. Be prepared for the fact if it does come apart it may damage more expensive parts like the trans or the crankshaft. How is that bronze insert held in?? Bolted from the backside?? Press-fit?? Shrink-fit?
The pits are not the problem. That little bit of missing material is small compared to the missing material in the slots between the segments. If the pits were the only concern, run it. The question I've never had to answer is the one which was raised about corrosion migrating under the facing. It's unlikely that has happened, but as mentioned, the penalty for being wrong is high. jack vines
While we are discussing this rare flywheel that would also fit a caddy 331, have any of you guys ever built a flywheel? As rare as these are, I was considering trying to build one for my caddy motor. I have access to everything I would need to do it. If I could get it figured out, I could make extras… Don’t mean to hijack your thread @tubman but it seemed relevant…sort of.
No problem Jeff, given the wide range of responses to this thread, yours seems to me to me the most practical.
Looks like it’s a bonded insert and I think it’s a great idea to machine out the old one and install a new insert. They have a 11 inch at summit
I haven't scratch built one, but I did modify a Pontiac flywheel to fit a 500 Cad. There are probably a lot of flywheels that can be easily modified. Just look for ones that are either the same diameter or larger. Its no problem to remove a ring gear and turn the OD to the same size as the correct flywheel and reinstall the starter ring. There is usually plenty of room to add an alternate set of bolt holes. Then you have to look at how far the ring gear is spaced from the engine block. On mine, the stock starter would not work because the support at the gear end of the starter would not quite clear the ring gear. I used a geared mini-starter which I wanted to do anyway for the extra room it provides for the headers. This presupposes that someone is making a neutral balance flywheel. Also, on mine I only had to open the center hole a short distance to fit the Cad, so the rest of the bore is still Pontiac sized. It will fit a Cad or a Pontiac now. Here is a comparison of the ring gear location between a Cad and Pontiac Front view In this case the hole pattern was not symetrical so I drilled it using the Cad as a drill gage. Could have done it with a rotary table. Here it is being tested on a block/crank with some used bearings in the block. Works great...... There are lots of cheap used steel flywheels to try this on. Then get a not so nice aluminum one and modify it for whatever rare set up someone has. Edit add: Be sure the flywheel you select has a center bore no larger than what you will need, and room for the bolt pattern to not be too close to the center bore.
Yes I know for sure that Ross Racing and Bendtsens Speed Gems both make very nice steel billet flywheels, adapters and complete kits for early Olds. They are not cheap but they are USA made and very high quality.
Not cheap is correct: I bought one from Bendtsens and I still had to cough up more money at a local machine shop to get the flywheel re-drilled for a Long pressure plate and the extra hole for the locating pin on the Cad crank added. Then I found a NOS Schiefer aluminum flywheel here on the HAMB and used it instead. Very happy with it...
The Jalopy Journal
