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Engine Block to Bell Housing Dowels

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Old 04-20-2006 | 07:29 PM
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Default Engine Block to Bell Housing Dowels

Who makes offset dowels,of choice?....Thanks for any recommendations.
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Old 04-20-2006 | 08:46 PM
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Default Re: Engine Block to Bell Housing Dowels

why?
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Old 04-20-2006 | 08:57 PM
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Default Re: Engine Block to Bell Housing Dowels

Mercury doesn't use them in the Bravo application.
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Old 04-20-2006 | 11:07 PM
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Default Re: Engine Block to Bell Housing Dowels

Might check TransDapt. They specialize in making engines and trannys that were never made to go together work. They have all kinds of engine to tranny adapters so I guess they would have offset dowels as well.
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Old 04-21-2006 | 08:40 AM
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Default Re: Engine Block to Bell Housing Dowels

This application is drive line transmission.....The purpose of offset dowels is to "dial in the bell housing to the crank shaft centerline"....Subject to the amount of variance between the bell housing centerline and crank shaft centerline would be the value of the off set dowels.....When both,crank shaft and bell housing are centered,the transmission input shaft will not be required to turn in an angle of deflection......That is,if the transmission bell and input shaft don't have run out.......A little less bearing stress , reduced harmonics,heat and flex plate abuse.
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Old 04-21-2006 | 11:54 AM
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Default Re: Engine Block to Bell Housing Dowels

Boy, nobody ever checks that!! And it causes a lot of trouble. It is VERY common for the crank to not be concentric with the bore in the flywheel housing.

Instead of the dowels, we use a fixture from Tilton, block is drilled oversize and an oversize dowel is inserted (just bigger on one end).
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Old 04-21-2006 | 12:24 PM
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Default Re: Engine Block to Bell Housing Dowels

CcanDo,
Tavia, Lakewood and Moroso make the pins you are looking for. We used the Lakewood products in our roadrace projects.
http://www.tavia.com/cat6.html
http://go.mrgasket.com/pdf/bellhousi..._procedure.pdf
http://www.moroso.com/catalog/catego...?catcode=23004
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Old 04-21-2006 | 08:56 PM
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Default Re: Engine Block to Bell Housing Dowels

Thanks guys for the information!!!!!Mbam,a dumb question,do you check the transmission case for run out before installing the input shaft,on new or rebuilt units?.....Second,have you considered designing an input shaft long enough to provide a pilot bearing shaft end?.......Third,are there words of wisdom pertaining to the flex plate?........Fourth,is a dampened drive line such as Aqua Drive recommended?......Everyone,please feel free to chine in!!!Thanks
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Old 04-21-2006 | 10:32 PM
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Default Re: Engine Block to Bell Housing Dowels

run out would be a bent shaft, concentricity would be a trans housing out of spec, yes we do check. The shaft is way too hard and short to bend without cracking. In the case of a problem exceeding the float in the drive plate it usually will take out the bearing. Have thought about a pilot, does not really solve the problem. The drive plate we use has abut .030 float built in but to me that is a band aid. Much better to eliminate the run out and concentricicity issue. What drive are u using?
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Old 04-22-2006 | 06:56 AM
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Default Re: Engine Block to Bell Housing Dowels

Mbam,I stand corrected on loosely using run out....The point is,concern for tolerance of the case centerline to shaft centerline...The next concern is centering the flex plate to the crankshaft....Then preserving the integrity of the flex plate hub assembly and transmission front bearing....The pilot would support the over hung load...The drives are dry sump #6 w/ 27" drive line....Thanks
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