B44 Inner Timing Cover Damage and Differences

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csx355
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B44 Inner Timing Cover Damage and Differences

Post by csx355 » Tue Apr 02, 2019 8:35 pm

Hi all. When I stripped my B44 motor I discovered a blown crankshaft main ball bearing, most of which had deposited itself in the sump. A consequence of this was that the resulting crank 'wobble' had munched the end of the crank into the timing cover. The edge where the oil seal sits is undamaged however there is significant scuffing, scratching and scoring into the bottom of the casings oil feed. See pic
IMG_0025 2.jpg
I'm pretty sure the the casing will clean up without disturbing the oil seal seating surface however I have an opportunity to get another casing. The part number on the original casing is 70-9405 - the potential replacement is 71-1115. I can't see any difference and the parts books seem to list several other numbers.
Any thoughts and advice on this would be gratefully received.

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Re: B44 Inner Timing Cover Damage and Differences

Post by kommando » Wed Apr 03, 2019 8:07 am

There will be differences, only close examination will tell you what they are and if they matter. I would try to keep original as they were machined as matched sets with the cases and some will give issues with mismatches on shaft hole positions.

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Re: B44 Inner Timing Cover Damage and Differences

Post by ampshire-og » Wed Apr 03, 2019 1:42 pm

Inner timing covers are generally the same however have subtle differences. main difference being kick start bore for the B50 compared to the b25/b44. other differences are oil switch hole, rubber boot for points wire, circlip for oil feed seal for the B25, etc etc. Kommando is quite right about alignment and interchange ability. I have changed out cases but had the cam bush line bored to ensure alignment. I would have thought that if your case only has the damage in the picture I would stay with what you've got and just get it cleaned (find a friend with a mill and clean up the damage a slightly smaller slot drill) so long as the seal is still a tight fit in the case. :thumb

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Re: B44 Inner Timing Cover Damage and Differences

Post by tridentperu » Thu Apr 04, 2019 3:20 pm

There is another difference too with apparently suitable cases. The B44 crank nose is slightly shorter than a B25 one, so a B25 cover (with the circlip retaining the oil seal) will not do , as the b44 crank won't quite reach the oil seal...not good!

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Re: B44 Inner Timing Cover Damage and Differences

Post by ghislain » Mon Apr 08, 2019 2:43 pm

Some have an "o" ring fitted beetween cases around oil drillings ,older ones don't have ...and even with two apparently identical I got the problem of kicksart quadrant needing reducing overall width to fit, otherwise it was too tight and hard to move when cases were closed ... <201
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Re: B44 Inner Timing Cover Damage and Differences

Post by minetymenace » Mon Apr 08, 2019 3:58 pm

Kick start arrangement changed about '71 along with gearbox main shaft and bias adjustment of gearshift....
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Re: B44 Inner Timing Cover Damage and Differences

Post by ghislain » Mon Apr 08, 2019 5:19 pm

Yes, Minety, but no :werd
Problem occured when building a B40 GB, mostly with new parts from MCS...Long time ago !!! :mrgreen:
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