i've read everything i've ever seen on here about nailhead flywheels and bellhousings. i'm aware that there are different flywheels for different years. questions: what year(s) flywheel will fit (with no modifications) on a '63 401? what year(s) flywheels can be modified/machined to fit on a '63 401? what modifications will that require? TIA!!!
all flywheels from 1961 to 1966 are a direct fit. the flywheel from the 1957 to 1960 with 364 or 401 will fit but you will have to have a small ring machined for the flywheel to fit the hub on your crank. Hope this helps.
Can a full aluminum one ( no steel insert )be used on the street? I bought one for my '61 401. I dont mean to highjack your post Atch, but I thought since our engines are almost the same, and the Nailhead experts would be here anyway...
suede - thanx. that's more info than i've found so far and expands the possibilities for me to search out. that gives me all the years from 57 through 66 to look for. is there anything that can be machined on the 53 - 56 flywheels that will allow them to work? metal - don't mind a bit. the more info the better. i'm sure that there are more experienced heads here than me, but my opinion is that an all aluminum flywheel on the street would probably not last as long as a steel wheel or an aluminum one with the steel insert. but what do i know? i've never used one. that said, i'd rather have an aluminum flywheel in a running rod than to be holding out for a steel one and not be able to drive the car. of course there's always the option of buying one from poston, but i'd rather find an original for less than the $275 +/- that poston gets.
i've heard that one is externally balanced and the other internally. which is which and what would i need to do to a 364 flywheel to use it on the 401?
If you come across a 322 manual flywheel, e-bay it: those are pretty hard to come buy, and I don't think they'll work with the 401. I wondered long and hard about going with an aluminum flywheel, because they pop up on ebay kinda regularly. My problem is that back when those things were made ('50s-'60s), they had a real problem with flywheels coming apart and taking out the floors, dash, windshield and the driver's feet! Hence the need for blow-proof bellhousings. And I've never seen one of those for a Buick Nailhead. I held out and found an OE steel flywheel for my 322. Just my .02 -Brad
[ QUOTE ] i've heard that one is externally balanced and the other internally. which is which and what would i need to do to a 364 flywheel to use it on the 401? [/ QUOTE ] The balancers for both look fairly similar. But I'm not sure what exactly the right answer is. But when I was putting a TH400 behind my 364 I was using a flexplate from a 401/425 and was informed that it had to be rebalanced. I checked with some of the other Nailhead guys. It was true there is a significant difference in the balance of the engines. So I had the engine rebalanced. I can't remember the difference in weight.
The diameter of the 322 is wring for the later motor. I use an aluminum flywheel with a bronze face on the street with no trouble.I did have the flywheel and my rotating ***embly balanced before I installed the motor and I can turn 5500 rpm without a hickup. If you use a steel flywheel which is harder to obtain you can balance before install at your local machine shop. Good Luck and have fun with your nailhead. If you need a flywheel or any other parts let me know.
The pilot bearing is another fiasco with these engines. It helps to order one from a 2 ton gm truck, because they had nailheads.
One of the great Nailhead resources is Carmen Faso 716.693.4090 - J&C's Parts 7127 Ward Road North Tonawanda, NY 14120 No website, no email, but a wealth of knowledge and parts.
63 was last year for dynaflow. 57-63 will fit. If it's off a 57-61 364, it will have to be rebalanced. If it's off a 59-63 401, you'll be OK. If it's from a 64-66 401 oe 425, the hole that fits over the crank flange will have to be machined a little bit larger, to fit the dynaflow crank's larger pilot hole, then it will bolt up. Remember to keep the little dimple on the crank lined up with the extra little hole in the flywheel. All the AL flywheels I've seen for sale for these motors have had steel inserts. That oughtta say somethin.
bttt 'cause there's some really good info here that i'm sure someone else needs to see and also just in case anyone has more information to add...
Thanks Atch, For my aluminum Flywheel I was thinking about using it as is, or maybe I should have the friction side anodized. I'm not sure if I should use a regular Clutch plate or if there is a special one I should be looking for... I did not know that those old aftermarket Flywheels would explode easyer than a stock cast iron one, but since I want to use a Super T10 with it, I will have to make my own Bellhousing anyway. I was thinking about cutting up and modifying a old Lakewood ****tershield that I have. That should catch most of the shrapnel, even after being modified...
Just to be clear, I'm not saying that the old aluminum flywheels DO blow up--I'm saying that I've read enough vintage mags from the early '60s, and had a talk with a guy who was hired to figure out why the flywheels of the day would go bang. My own, personal feeling is that I want a factory iron flywheel, because the OE was held a little more accountable for their stuff than a small aftermarket company. It's just my opinion on the vintage aluminum flywheels, though I personally haven't seen one grenade, nor have I talked to anyone who had one leave on them. -Brad
I am currently racing on an original scheifer with a bronze insert. It's on it's second year and I had it x-rayed with a clean bill of health. I still run a ****tershield so I don't do a Garlits, But I have faith in it. Bith my flywheels use ford 3 finger 11" pressure plates and clutches. I made my pilot bushing from Machine bronze as well. The steel flywheel is tougher but it can spin the Rpm's like the aluminum can. In the end what matters is what you want to use the car for and what you can afford. Good Luck.
Brad, I was a little surprised to hear they would explode, because I thought aluminum was a lot stronger in tension than cast iron, and there would be less centrifugal weight tugging on it at the same RPM... But I forgot about the lesser quality control that might have been acceptable in the old days... Either way, it is good information, and I will run some sort of ****ter shield. I have an old Ansen ****tershield in my roadster too, and it also has an Aluminum Flywheel...
[ QUOTE ] but since I want to use a Super T10 with it, I will have to make my own Bellhousing anyway. [/ QUOTE ] actually you can machine one of the older bellhousings to accept the late ****** bolt pattern and the larger hole for the input shaft housing. see street rodder november, 1997 (or maybe it was december, i don't have it with me here at work). they show how they machined one and made it work. i've got it at home, but no way to scan it to post it or send it with an e-mail. i'm not a machinist, but it looks pretty easy and straight forward to me.
earlier in this post zman mentioned carmen faso in north tonawanda, new york (716 693-4090). i spoke with him this morning and he does seem to know his stuff. he sells new billet nailhead flywheels and gets $275 for them. just thought that some of you might be interested in an alternative source of nailhead flywheels in the northeast. poston is in atmore, alabama (http://www.postonbuick.com) and gets about the same $ for one. anyone got any other sources for them?
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