Flywheel bolts and locking up the motor

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enio45
Posts: 587
Joined: Wed Jul 02, 2003 6:56 pm
Location: Gilbert, AZ

Flywheel bolts and locking up the motor

Postby enio45 » Sun Nov 27, 2016 1:11 pm

Short story, big disaster but here it goes....

Working on a 56 Boano car for a client - needed new clutch and flywheel surfaced etc.

When i reinstalled the flywheel, i got new bolts and bolt clamps (straps with the tabs) and installed the flywheel.

I did notice the bolts were slightly longer than the orig's, but check the length and determined that the amount sticking thru was .040 - .050 was ok, as i have plenty of room at the back of the block. i checked the crank distance at the top side the crank to the clock to determine this. Installed everything 4 months ago - awaiting for other parts, detailing the engine compartment, refurb rad etc.

Go to start the car on friday and the car is locked up solid.....WTF!! Starter kicks in but motor would not turn. pulled the plugs - same thing, pulled the starter , try to turn the flywheel - same thing, pushed the car and let out the clutch - locked up solid. I took all the interior back out of the car - pulled the trans , clutch and flywheel and sure enough, the lower bolts on the flywheel were tightened into the rear of the lower block housing (which is removable in its self). The clearance
on the lower side of the crank to the lower block housing is very close - maybe .015-.020 i believe. i did not see that - i checked the top side of the block and had a good 1/2 inch.

What a freakin mess....in addition - the heads of the new bolts were slightly taller so we had to machine them down because the threads on the bolts had a shoulder that would run out of thread material so we added a lock washer in place to pull them back.

6-7 hrs R&R for the 2nd time was a wasted day, tough lesson to learn.

:x
Ed Montini
330 GT 2+2 Series II - 8289
58 Ellena - 0855GT - orig drivetrain

Jimmyr
Posts: 377
Joined: Thu Aug 19, 2004 11:20 pm
Location: Scottsdale, AZ

Re: Flywheel bolts and locking up the motor

Postby Jimmyr » Mon Nov 28, 2016 12:06 am

Ed, also be sure the bolt heads do not extend higher than the flush surface of the flywheel. That is why they use that flat locking strap in place of lock washers. The bolts are special grade 10 as well as the special length - as you have found out. Jim

enio45
Posts: 587
Joined: Wed Jul 02, 2003 6:56 pm
Location: Gilbert, AZ

Re: Flywheel bolts and locking up the motor

Postby enio45 » Mon Nov 28, 2016 12:26 am

jimmy, yes agree - we had to shave the heads down .030 to minimize any future interference.....heads on the bolts are quite thick to begin with.
Ed Montini
330 GT 2+2 Series II - 8289
58 Ellena - 0855GT - orig drivetrain

User avatar
John Vardanian
Posts: 1644
Joined: Wed Sep 04, 2002 12:13 am
Location: San Francisco Area

Re: Flywheel bolts and locking up the motor

Postby John Vardanian » Mon Nov 28, 2016 1:26 am

As long as there is no damage or no fingers missing, no big deal. Glad you figured it out and were not too proud to share.

john
PF Coupe

enio45
Posts: 587
Joined: Wed Jul 02, 2003 6:56 pm
Location: Gilbert, AZ

Re: Flywheel bolts and locking up the motor

Postby enio45 » Mon Nov 28, 2016 11:52 am

Thanks John, no missing or damaged fingers

Yes, i felt it was necessary to share this so anyone else doing a flywheel and clutch will at least be aware!!
Ed Montini
330 GT 2+2 Series II - 8289
58 Ellena - 0855GT - orig drivetrain

User avatar
John Vardanian
Posts: 1644
Joined: Wed Sep 04, 2002 12:13 am
Location: San Francisco Area

Re: Flywheel bolts and locking up the motor

Postby John Vardanian » Mon Apr 10, 2017 1:30 am

Can anyone post a close up picture of the bolts that hold the clutch to the flywheel? Thanks.

john
PF Coupe


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