Re: Engine Block to Bell Housing Dowels
 

Both Imco & Konrad use a shock absorber on the output of our trans for some applications.

Drive plate run out is a concern, we have seen some production plates off by .060, transmission did not last very long on that one.

The hub will move, it is designed to have some float. If you mount the drive plate on the flywheel and put an indicator on it you can center it with a hammer and brass drift. If not -- dump that drive plate.

We like to see no more than .007 total run-out & misalignment but I promise there are 100's of units running with far more than that. It does make the unit run hotter and will cause low line pressure if off too much. Very seldom do we see a shaft or bearing that has been damaged.

The tolerance of the transmission case is a non issue, they are within a couple of thou worst case. If the crank/trans centerlines line up there really is no overhung/radial load to speak of as the drive plate will handle the .007 spec no problem. If they don't line up a pilot is not going to solve the problem, something will eventually break.

Re: Engine Block to Bell Housing Dowels
 

Thanks Mbam,good information,other people may benefit from your statements also.....FYI,Mr.Gaskets @216-398-8300 offers a Lakewood Industries offset dowel in three sizes.The dowel appears user friendly and does not require drilling or tapping.....Some flywheel,drive plate, crankshaft bolt combinations create drive plate hub/crankshaft bolt interference....Therefore,is it acceptable to shim washer between the flywheel and the drive plate,thereby creating clearance between the hub and crankshaft bolts?....Further,is it recommended to use fasteners on both inside and outside bolt circles of the drive plate/flywheel?....It seems there is less risk of heat/work hardening without shim washers and both bolt circles are used.

Re: Engine Block to Bell Housing Dowels
 

MBAM, Ok, we have checked bell housing to crankshaft run-out. With dial indicator on zero at 3 o'clock, we found .006 @ 12, .0145 @ 9 o'clock, .0065 @ 6 o'clock. Please correct me if this is wrong, but my conclusion is that we have zero run-out top to bottom, and .00725 run-out side to side. If this is correct, do we need to re-dowel to reduce the +-.007 run-out, or is this value acceptable?

Re: Engine Block to Bell Housing Dowels
 

Yes, that is what is sounds like. .0145 is a bit much, would be nice to see it lower. Did u check the drive pate hub run out?

I would not shim the drive plate out, is it the hub hitting the bolts or the flywheel, sometimes the recess is not big enough. We use a dished drive plate, gives better engagement on the input shaft and avoids the interference issues.

Re: Engine Block to Bell Housing Dowels
 

Mbam,with your tutor age,the flywheel is at "0" and the drive plate is at.0035.The drive plate is fastened at both the inner and outer bolt circles without spacers or interference......Sure a lot of trouble just to make these Bam Transmissions happy.....Thanks Again

Re: Engine Block to Bell Housing Dowels
 

Marc, Lloyd-
Great info here guys.
I'm going to check the runout on my setup when I have the chance.
Thanks!
John

Re: Engine Block to Bell Housing Dowels
 

Guys, a somewhat related question, I use Merc crashboxes and spline drives,I posted when initially set up ,about 45 hrs ago, to see if I should use a pilot bushing, Everyone told me not needed although the tip is on the input shaft. There are no wear issues thus far but this has me thinking. Food for thought.....good info...but maybe more work! Due, the Chris's engines are done AGAIN :mad: and she will be ready to fight in a few weeks. :D

Re: Engine Block to Bell Housing Dowels
 

Greencard,I would run a sealed,hi rpm ball bearing pilot....Because,the drive plate hub splines have tolerance and the hub itself can move....The bearing will stabilize the drive plate assembly....However,the bell housing bore and crash box flange should be close to a press fit and centered.

Re: Engine Block to Bell Housing Dowels
 

Andy-
Is this the second time for your engines? Hope they stay together.

By the way, you can trust CCanDo's advise; he's never led me astray.
Altho, he may have let me stray... at my own peril.

John :D

Re: Engine Block to Bell Housing Dowels
 

CC, thanks for the tip, I will look into it. Trans fits tight to belhousing.
Due, when the seastrainer lid exploded one engine got hot and the other sucked the spaying water into the carbs :eek: A Couple pistons and some bent valves so I got off easy..just need relief valves or different strainers. Alot can happen quickly at 100+.