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Mike Van Veghten
09-07-2005, 04:38 PM
On the "nut-bolt" / "cap screw" thought.

Has anyone just tapped the back of the crank or put inserts in the flange to accept cap screws like most any other engine? I'd like to be able to swap from an automatic to a 5 spd. when/if McCloud gets their scattershield done without dismantling half the car.

Roscomacaw
09-07-2005, 05:16 PM
I have heard of someone tapping the existing holes. Of course, this requires larger hardware and enlarging the holes in the flywheel or flex plate.
I only know I've read of it being done. I don't remember any pro-con results. As you say tho - it would be handy!:D I'm not fond of the goofy hub and bolt arrangement for the dampner hub either.[}:)]

BTW, lest anyone here (other'n you, Mike) goes running for their tap and die set - this would be something best left to a machine shop.

Miscreant at large.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President 2-dr
1955 President State
1951 Champion Biz cpe
1963 Daytona project FS[B)]

N8N
09-07-2005, 05:35 PM
Wouldn't tapping those holes still require minor engine disassembly? Unless one had a REALLY GOOD tap and die set with an appropriately sized bottoming tap, that is.

nate

(wants a set of bottoming taps for Xmas.)

--
55 Commander Starlight
62 Daytona hardtop
http://home.comcast.net/~njnagel

Alan
09-07-2005, 05:58 PM
Mike: The crank flange on a Stude V8 is only .343+ - .003 not to many threads to put in there you would have to use 7/16" X 20 tap but the holes on the Stude crank are .378 and the tap drill on 7/16" X 20 is .390 so you would have to make a drill fixture drill all 6 holes out to .390 then a tap fixture to tap the hole straight, then you have to ream the holes in the flywhel for a .002-.003 slip fit for the bolts but has to be tight because you dont want the flywheel to move if you have ever seen a flywhell go you will kiss your stinky feet that they are still there. Just drop the pan and rear main cap and do it right. On the 5 speed part just find a Stude bellhousing with the Chevy pattern and bolt one of the new Tremic 500 or 600's up all you have to do is go to the Long Beach swap meet and get a $3.00 chevy pilot bearing and turn it down from 1.094" to .940" and just pop it in, but you have to remove the Stude pilot bushing they even put one there for the auto's. It should be .940" X .750". Of course the best way is to rebuild your engine and ballance it properly, then you won't have to worry about every vibration and noise.

Mike Van Veghten
09-08-2005, 11:25 AM
Thanks guys,

Yea, a jig would have to be made, no problem.
The only thought would be larger dia. fasteners or inserts. The edge margin needs to be checked to verify the thickness of the remaining material from new thread diameter to the outside edge of the flange. The flange thickness is relitivly thin, but a 3/8" dia.(as is stock?) has plenty of material. Slightly thin with the use of 7/16" dia.
Again, something to look into.

Since this is a fresh rebuild, and knowing I do have the wherewithall.......I'll let the crank grinder do the work!

As for the flywheel/flexplate hole diameters. No problem there either. Ever check the hole to fastener difference on the big three? They are pretty loose!!!

Again, thanks. I'd a thought more may have done this.

64Avanti
09-17-2005, 12:34 AM
The biggest problem with tapping the crank is something that Alan mentioned. There aren't enough threads to properly torque the screws without risking stripping the threads in the crank. You could use lok-tite and torque to about 3/4 the proper torque. The best bet is to leave it as designed.

David L