A good number of years ago, Jack Clifford use to catalog and sell a 30 pound 10.5 inch steel flywheel for use on the 55-62/3 235 and 261 chevys. McLeod was the supplier. I purchase one in probably 84 or 85. Been using it ever since. Racing, street driving, hijenks, lol. Replaced my beloved Schieffer clutch and pressure plate two yeas ago with new Ram pieces. The flywheel looked as good as the day I installed it.
My 20 something son is in the process of building his first motor, a 261 chevy for his 57 chevy sedan. I really did not want to use a used flywheel, and would have really preferred a steel unit just because its was stronger and durable. Over the years I have called McLeod but it was usually we cant do that any longer.
I decided to give one more go at it and sent an email to McLeod and got a response that has me clicking my heals. Someone knows what I am talking about and dug into McLeod's published and unpublished catalog. Turns out, then can make one.
If anyone is looking for something decent and new in terms of a flywheel, you have to call and order directly from McLeod. The part number is 460139 and is not a published part number. The flywheel is a steel 30 pound unit with a 10.5 face for the clutch, but I was made to understand they could also machine for an 11 inch. These are made to order and its a 6-8 week lead time.
Cost is $480 in steel. Not inexpensive but not completely out of hand as I have been quoted in excess of $800 by another manufacturer.
For anyone who is looking for something in Aluminum for say a dirt track motor or the like, they can make one up in aluminum for $750.
Again, you have to call McLeod directly to order these flywheels. The contact person there is Billy Mieczkowski.
What does a stock flywheel weigh, and what's the advantage of a lighter one? On the round tracks, we used a small diameter clutch with three friction discs called a "circle master", I believe, along with a flex plate for an automatic transmission so the starter had something to drive. That one had very low inertia which allowed a driver to accelerate off a turn quicker, and drive deeper into turns- - - -effectively "stretching the straightaway" by a few feet. That clutch was totally unsuitable for street use. Slipping those small discs to get started caused massive shudder- - - -"Rev it up and sidestep the clutch pedal!" I've been known to set up a stock flywheel on a brake drum/disc lathe and whittle about 5 pounds off the back side. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
30 pound steel for street use, drag strip, truck use. Motors need the inertia to get up and going. Aluminum for racing, low inertia, get the rpm’s up quick. Same theory as what you were using. And yep, aluminum is not for street use. There is actually an aluminum Schieffer on eBay, brand new. But no real competitive use these days. So it has been sitting unsold.
But a steel flywheel, wears like, well, steel, lol.
Just curious. Lot’s of different types of steel. Are they specifying what type? A36 and 1018 for instance are low carbon mild steels. A36 is usually hot rolled and 1018 is cold rolled.
I would think they will be using an alloy such as 4140-4142 or better. The alloy steels are much stronger.
I’m just wondering if you’ll be getting equivalent or better than the original you bought many years ago.
John
~ J Lucas 2006 GMC Envoy 4.2 I6 2023 Ram 2500/Cumins 6.7 I6 2010 Jeep Grand Cherokee (Wife’s) 2002 Silverado 2500 Gas 6.0 1941 Chevy 1/2-Ton 1942 Chevy 1.5-Ton SWB In the Gallery My Flicker Photos!
Maybe. I have never had a 302 to play with. But all of the 235/261 cranks had three dowels with one offset. The offset dowel located the flywheel in correct orientation on the crank with the timing bb in the flywheel. It’s what made those flywheels so hard to come by. And I am not certain anyone other than McLeod ever offered the more durable steel version.
As for the material, this is what is advertised:
“billet alloy steel and have 1045 hardened steel ring gears”
all of the 235/261 cranks had three dowels with one offset. The offset dowel located the flywheel in correct orientation on the crank with the timing bb in the flywheel.
Actually, the dowels are equally spaced 120 degrees apart, and they align with the companion cylinder pairs. The six bolt holes are also equally spaced, but they're offset a little bit so the flywheel only bolts onto the crankshaft in one position. I use the dowel pins to index the crank in the lathe and the crankshaft grinder when I'm making the stroker crankshafts, to assure that the three paired sets of bearing journals stay in the proper alignment with each other. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Sorry, Jerry, but Evan is correct. I just measured dowel hole to dowel hole dimension on an AD flywheel that was on a 1958 235, and they are NOT equidistant from each other. So they can't be equally spaced at 120 degrees.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
OK- - - -just measured a crankshaft, and that "equal space" is an optical illusion! I'll have to redesign my indexing fixture for roughing out the stroke change on the lathe. Thanks! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Better to find it now than after grinding on a crankshaft. That would be an expensive oops. I used that flywheel as a base to drill crankshaft snouts and had to keep turning the crank till the dowels matched up with the holes when setting the crank on the flywheel. Of course it didn't fit the first try and I had to turn it 120 degrees TWICE by going the wrong way. LOL!
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
As I noted above, all 235/261 chevy cranks have three dowels, one is offset to correctly locate the flywheel on the crank so that the timing bb is correctly positioned to indicate tdc. On the powerglide equipped 235 pass motors, same deal. Three dowel holes in the flex plate. It’s actually pretty ingenious!
Not as ingenious as GMC. They just offset one of the 6 bolts and didn't use the dowels at all.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
On GMC's without dowels how to you figure out which bolt to insert in which hole when installing the flywheel? With dowel pins, you can get the flywheel in place in one of three positions, then install the bolts. With a GMC you may have to try 6 times before getting the right bolt in the right hole.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Probably not so bad when you have the engine out or have a lift. I’d hate to install it when it is in the vehicle and I’m on my back!
Phil Moderator, The Engine Shop, Interiors and Project Journals
1952 Chevrolet 3100, Three on the Tree, 4:11 torque tube Updated to: ‘59 235 w/hydraulic lifters, 12v w/alternator, HEI, PCV and Power front Disc Brakes Project Journals Stovebolt Gallery Forum
I guess if I was installing on my back I would first find the "odd" bolt hole and install a decapitated bolt into the odd hole with the odd hole rotated to the highest point. Mark the odd hole in the flywheel and then hang the flywheel on the crank. Install the other 5 bolts, remove the headless bolt and install the 6th bolt.
Maybe the dowels are a better idea, but it seems to me that you'd only need 2 as long as they were not directly across from each other..
Last edited by Bill Hanlon; 02/26/20255:36 PM.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
Well, McLeod told me 6-8 weeks. Took them two weeks. I am going to have to do a little measuring but the flywheel may be drilled and tapped for both a 10.5 inch pressure plate and an 11 inch pressure plate.
Today was install day. The flywheel is a darn work of art. My son and I had to take our time getting it installed as the tolerances are as new, which is to say it just does not drop in. We had to get it lined up on the dowels, seat it more or less even as it would not just seat on the crank flange and you can’t use a dead blow hammer to seat it (tried, did not work just cocked ever so slightly and that was that) so we used the bolts and turned a little bit at a time on each bolt and seated the flywheel.
This thing cost me a couple of dollars but after installing it, I was fine with the cost. I did not have to hunt a used flywheel that had never been machined before and was not grooved to death. I did not have to clean old grease and grime off. I did not have to do any de rusting, did not have to have it machined, did not have to flip the gear around to get a fresh gear face.
All in all, it’s pretty nice and it’s nice to have something pretty nice, even if it is just a flywheel, lol.
