Inliners International Forums General Discussion Drive Train What flywheel for 250 Chevy and Muncie

I am shopping a flywheel for my Muncie and Chevy 250-six for my 65 Nova. Found one that has a bolt hole stripped. If it is the right one Can I re-tap that?

1) What flywheel should I use (same as SBC/BBC?)165 tooth.
2) Anybody have any experience with a hydraulic clutch set up? Howes?

Thanks Guys n Gals

james

You can use either the 153 tooth or 168 tooth small block Chevy V8 wheels as long as they are for the INTERNALLY balanced engines and not for the 400 small block or the post 85 engines.

The 153 will only take the 10.4 inch clutch, while the larger wheel will take an 11 inch clutch.

The starter will have to be compatable with the flywheel. Both starter bolts in alignment goes with the 153 and staggered bolts on the starter goes with the 168.

You also have to have the correct bellhousing to clear the larger flywheel and associated p-plate and clutch. The one with a bulge for the starter is for the 168 wheel. The one with a flat side at the starter location is for the smaller wheel.

Can I re tap a stripped bolt hole on a flywheel? safely?

James,

Is one of the threaded holes for the pressure-plate attachment screws stripped? Usually a stripped hole is missing some of the parent metal and retapping it would result in imperfect threads. A threaded insert (Keensert) could be installed to provide a good thread. Aluminum flywheels use steel inserts.

I am using a Howe hydraulic throwout bearing with my 261. Seems to work just fine.

Hoyt, yes it is steel and it is the pressure-plate threaded hole. Do I need to take it to a shop to have the keensert put in? Or could I pull this off at home?.

Di I understand the Howes right? No z-bar? Only a master cylinder to worry about and the hydraulic line? Seems like a dream to me. Is there a downside?

Thanks

James

James,

If someone has never installed a Keensert previously, a flywheel is probably not the best part with which to practice. The new hole and threads for the Keensert must be drilled and tapped perpendicular to the surface of the flywheel. This is a job that should be performed by a machinist.

Yes, the hydraulic throwout bearing eliminates all mechanical linkage, the clutch fork, or an external slave cylinder. Just a line from the master cylinder to inside the bellhousing is all that is needed. However, there is no easy method for adjusting the freeplay with the Howe bearing, as the freeplay is determined by installing a stack of shims during the installation of the transmission. The transmission would need to removed to add or remove a shim. Does any one make an adjustable bearing?

Yes, McCleod makes them.

http://www.mcleodind.com/application_guide_pgs/HYDTOB_SlipOn.html

If you end up using the stock bell housing for a Chevy II, only a 153 tooth flywheel for a pre 86 internally balanced sbc will fit. A 400 will not work as it is externally balanced. If you go hydraulic, it doesn't matter what you use for the bell housing.

This is getting good now. At least i know McLeod makes the goods to complete my dream of a hydraulic T.O. bearing. Yipee! NO mechanicals. I can do this, I already have the 153 type bellhousing as identified by Mike G. up there.
I will just have to find a good used 153 tooth flywheel, since I don't have the $350 for the catalog items out there.

Thanks for the info Nexxussian

Just make sure you have a good spot for the master cylinder and are willing to do the drilling on the firewall.

You don't have to spend over 300 for the flywheel. Your local Chevy dealer that carries GM Performance parts sells brand new nodular iron 153 wheels for under 180 bucks. It is a lightweight flywheel that weighs 15 lbs. I'm pretty sure they have the standard weight flywheel also as it is still used on the Mercruiser 3.0L ( 181 inch ) 4 banger. If you come across a used marine wheel the clutch surface and p-plate bolt holes will have never been used. Those engines only use the wheel for starter mesh and of course for inertia. The marine drive is from a coupler bolted directly to the hub of the flywheel and crank. Perhaps a light resurfacing and cleaning of the 6 p-plate holes is all they need just to clear any surface rust.

Found a steel 153 tooth on Ebay for $69...it weighs 18 pounds, any problem running a light one like this if I do not intend to race???

Mike G., I have a question about the marine flywheel for the 181. Is it common for them to be drilled and tapped for a pressure plate as would be used in automotive applications? I bought one of ebay for 99 cents, and it wasn't drilled and tapped. In addition, the "face" where the disc would seat had a slight counterbore, about 3/16" deep and 9.5 inches in diameter instead of being flat. Is this flywheel the exception rather than the rule?

Bob

My Mercruiser 165hp 250 six cyl. flywheel was tapped for a clutch. I used it on my 50 chevy with a 250 because it had a unused face (saving the cost of having my old one refaced)....SCRAP

Bob, my 181 came with the small diameter flywheel and it was tapped for a pressure plate. It also was Blanchard ground and ready for a clutch in a road application. The only modification from a car wheel I could see was the entire thing was painted in epoxy type black paint to prevent corrosion in the boat. It is a 1988 engine if that matters. A counterbore is correct to clear the clutch disc dampening hub but the one I have measures only 5 7/8 inches diameter. I checked a disc at 9 1/2 inches and guess what?, about 1/2 of the friction surface would be hanging into the counterbore you describe.
Hate to be the bearer of bad news but I think you need to get another flywheel.

A new flywheel it will be. I only paid 99 cents and $11 shipping for it on ebay, so it'll make a great base for a bench grinder pedestal. The marine engine guy I got the 181 from has a stack of flywheels I can pick from. He was dumbfounded by the lack of holes in mine as he says the holes are where the drive hub bolts in the outdrive application. By the way, the one I have has the small counterbore for the disk hub that you describe, but also has the larger one. I don't know what the deal is with this flywheel.

Bob

Ummm I think you need to talk to a different marine engine guy. The outdrive coupler flange bolts to the same holes as used to hold the flywheel onto the crankshaft flange. Only difference is the marine engine uses studs in the crank that are installed with Loctite instead of the usual flywheel bolts. The flywheel mounts over the studs and then the coupler goes on next and is secured with washers and locknuts.

I've never seen a flywheel like you describe so it might be a marine only use part. Then again I don't work on boats so maybe that's why I've never seen one.

At least now you know what you're looking for.