E: Engine Main bearing outer race width
- Thread starter Phil Arundel
- Start date
The flange is only there for installation. It is removed once the sleeve is installed. It still means having to bore the case to remove any bell mouth etc. It's not that thick so limits what you can repair.
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Sounds good in theory........More for a shaft where a seal runs, that has worn a groove in it. If it's main bearing retention you want to get it pretty right, unless you are happy to strip your engine on a regular basis.
Thats where I first ran into them. Repairing cranks for cars where the timing cover seal wore a groove in the crank. I initially wasn't going to post that, because I knew it would draw some negative reaction. With regards to bearings...at first I thought the same way, but after seeing it done... It is not the ultimate repair, but has it's place.
While hoping you don´t burn me on a haystack, would you consider a metric conversion including lipped modern roller bearings that will not walk out in the case like with the factory design - crappy design anyway, but reason was non-availability then. There are some features favourable for these metric types: The o.d is 62 mm , so you don´t weaken the case in this critical place. Just skim the wornout 63,5 mm diameter to accept a sleeve, alu or brass, and get a calculated shrink fit with the new sleeve after pressing in and finish bore so the bearings will let loose at about 120 degrees for future repairs - for other reasons than walked out races.
I would hate to fit securing screws for the outer race, another weak spot right here. Punch locking the races is a horrible bodge as well, don´t even spend a thought on what that does to the roundness of the race at the punch spots !
The roller bearing NJ 2206 contains the rollers in the lipped outer race and the inner race has one lip for easy assembling. On the drive side outer bearing I take the type with no lip on the inner race so that slips through both bearings and will position the crank via an axial ring between bearing race and chain sprocket bush, no ball bearing here .
The timing side has the narrow roller bearing NJ 206, 16 mm wide, and another small NJ , bearing no. 4 . Here is one drawback, the oil pump worm does not slip past the rollers when the bearing already sits in the case. So I will try to thread the case over the crank while the worm lies loosely in the space between inner bearing and the small outer bearing and hope to meet its slot with the woodruff key . If no success after end of patience , no big deal: Heat the case so the big bearing drops out again - thread it onto the mainshaft, the worm onto its place, the small inner race from the timing side outer roller bearing as the last item on the mainshaft - and lastly plunge the enginecase heated over the crank , done.
I should add, my crank has 30 / 20 mm mainshafts, so for the 1 inch shaft you could simply machine an adapter sleeve for the 30 mm fit.
Vic
I would hate to fit securing screws for the outer race, another weak spot right here. Punch locking the races is a horrible bodge as well, don´t even spend a thought on what that does to the roundness of the race at the punch spots !
The roller bearing NJ 2206 contains the rollers in the lipped outer race and the inner race has one lip for easy assembling. On the drive side outer bearing I take the type with no lip on the inner race so that slips through both bearings and will position the crank via an axial ring between bearing race and chain sprocket bush, no ball bearing here .
The timing side has the narrow roller bearing NJ 206, 16 mm wide, and another small NJ , bearing no. 4 . Here is one drawback, the oil pump worm does not slip past the rollers when the bearing already sits in the case. So I will try to thread the case over the crank while the worm lies loosely in the space between inner bearing and the small outer bearing and hope to meet its slot with the woodruff key . If no success after end of patience , no big deal: Heat the case so the big bearing drops out again - thread it onto the mainshaft, the worm onto its place, the small inner race from the timing side outer roller bearing as the last item on the mainshaft - and lastly plunge the enginecase heated over the crank , done.
I should add, my crank has 30 / 20 mm mainshafts, so for the 1 inch shaft you could simply machine an adapter sleeve for the 30 mm fit.
Vic
Oh, sorry, so it´s your turn first, what was your offence?
The crank, in fact, two of them, is sort of homemade, I started the Argentina B-Rapides projects about 30 years ago, so after retirement I am heavy into this job now. One´s lifetime is limited so hopefully in near future . . .
At that time our CNC Deckel mill was just a few years old - and myself a lot younger. So after two conrods for my 1928 750 sv BMW on the brand new Deckel CNC with still stressful moments - understandably - I set to realize my own ideas about engine details that I did not like with what I got in a few big boxes . So watch this place . . .
Vic
The crank, in fact, two of them, is sort of homemade, I started the Argentina B-Rapides projects about 30 years ago, so after retirement I am heavy into this job now. One´s lifetime is limited so hopefully in near future . . .
At that time our CNC Deckel mill was just a few years old - and myself a lot younger. So after two conrods for my 1928 750 sv BMW on the brand new Deckel CNC with still stressful moments - understandably - I set to realize my own ideas about engine details that I did not like with what I got in a few big boxes . So watch this place . . .
Vic
I still refer to mine as a Mongrel!