Page 1 of 1

Drive side bearing

PostPosted: Tue Feb 13, 2024 12:20 am
by Littlewheels
I'm rebuilding my engine and i've fitted the drive side bearing into the crankcase. After offering up the retaining plate to check that it sits low enough to clear the crank I found that it's a little too high so now i'm wondering if the bearing is fully home.

Obviously I know the height of the bearing (17mm) so from this I can work out if it needs to be pulled in further if I knew the depth of the recess it fits into. Does anyone know what this is?

Thanks

Re: Drive side bearing

PostPosted: Tue Feb 13, 2024 12:48 am
by Fast n Furious
Nominal depth of the bearing seat in the case is 19mm.

Re: Drive side bearing

PostPosted: Tue Feb 13, 2024 1:11 am
by Littlewheels
Thank you

Re: Drive side bearing

PostPosted: Tue Feb 13, 2024 1:56 pm
by bookertmgs1
Did you make sure that the halite washer OD was correct ? I've had some which are slightly too big so had to trim them down a tad. Made the DS retailing plate sit slightly proud.

Re: Drive side bearing

PostPosted: Tue Feb 13, 2024 8:12 pm
by Littlewheels
The Halite washer is ok for size but the innocenti retaining plate sits just about level without this fitted! The plate is 2mm thick and the recess to the top of the bearing is approx 2.4mm. The Halite washer is 1mm thick so whether it will compress sufficiently to enable clearance for the crank I don't know however I did also take time to measure the difference between the shoulder and crank web which is 1mm so as I say a lot depends on how much the washer compresses.

Re: Drive side bearing

PostPosted: Tue Feb 13, 2024 8:18 pm
by Toddy
Littlewheels wrote:The Halite washer is ok for size but the innocenti retaining plate sits just about level without this fitted! The plate is 2mm thick and the recess to the top of the bearing is approx 2.4mm. The Halite washer is 1mm thick so whether it will compress sufficiently to enable clearance for the crank I don't know however I did also take time to measure the difference between the shoulder and crank web which is 1mm so as I say a lot depends on how much the washer compresses.


You can get different size halite gaskets from a dealer , a tip I got taught was put some solder between the plate and bearing without the halite gasket
Tighten the plate down then measure the solder to see what measurement you get then you know what gasket to fit

Re: Drive side bearing

PostPosted: Tue Feb 13, 2024 10:07 pm
by Storkfoot
Toddy wrote:
Littlewheels wrote:The Halite washer is ok for size but the innocenti retaining plate sits just about level without this fitted! The plate is 2mm thick and the recess to the top of the bearing is approx 2.4mm. The Halite washer is 1mm thick so whether it will compress sufficiently to enable clearance for the crank I don't know however I did also take time to measure the difference between the shoulder and crank web which is 1mm so as I say a lot depends on how much the washer compresses.


You can get different size halite gaskets from a dealer , a tip I got taught was put some solder between the plate and bearing without the halite gasket
Tighten the plate down then measure the solder to see what measurement you get then you know what gasket to fit


I’m having a “why did I never think of that?” moment :idea: :)

Re: Drive side bearing

PostPosted: Tue Feb 13, 2024 10:27 pm
by Littlewheels
Thanks for the tip. I'll give it a try tomorrow.

Next decision is what type of screws to use, the c/sunk allen key type or the slotted screwdriver type. The allen key type are made from stronger steel but the slotted ones are zinc plated which may help to stop the reaction you get from mating two dissimilar metals? Then there's the loctite/no loctite but centre punch options :roll:

How do you fix yours?

Thanks

Re: Drive side bearing

PostPosted: Tue Feb 13, 2024 10:41 pm
by dickie
I wouldn't worry about dissimilar metal reaction. It's an overstated phenomenon and almost non existent in an oily environment like a crank case.

Also, you don't need high tensile screws in there. They don't have a high tension load in them.

I've bought fancy "better" screws in the past, but when you actually stop and think about it, there's no reason. When you strip a 50 year old engine that's never been apart before, they're always OK.

Re: Drive side bearing

PostPosted: Wed Feb 14, 2024 1:54 pm
by Littlewheels
Yes I see what you're saying about where the screws are in a bath of petrol & oil but do I centre punch or use loctite? or both?
Ive removed studs before that have been loctited (not by me) and its just striped the threads as I've unscrewed them :?

Re: Drive side bearing

PostPosted: Wed Feb 14, 2024 3:49 pm
by Storkfoot
I had an Allen type head start rounding off on me as I got a screw out several years ago. I haven’t used the Allen screw type since.

I use the slotted head type with a very small dab of Loctite on the thread just under the countersunk head. Centre punching was only needed in pre loctite days, I believe.

Re: Drive side bearing

PostPosted: Wed Feb 14, 2024 3:53 pm
by Toddy
Slotted or Phillips for me no Allen screw type small dab medium loctite and centre punched belt n braces :lol:

Re: Drive side bearing

PostPosted: Thu Feb 15, 2024 8:04 pm
by Littlewheels
Thanks everyone for the replies. I think I'm going to use an MB retaining plate which is 0.7mm thinner + slotted zinc plated screws with a smidge of loctite on the first two threads.

Re: Drive side bearing

PostPosted: Fri Feb 16, 2024 11:35 am
by hullygully
don't use up too much of that crank free space bud :shock:

Re: Drive side bearing

PostPosted: Fri Feb 16, 2024 3:32 pm
by Fast n Furious
Innocenti peen locked the heads of the plate retaining screws, cos back then it was the only practical way of locking these screws in place.
Today, A dab of medium threadlocker is all that's needed to do the same job.
As Storkfoot advises..... Don't use Allen or Torx head countersunk screws. Removal of the screws, in future, may need the use of an impact screwdriver to undo them. So, Slothead or Crosshead only.
Ideally, the plate should sit perfectly flat against the aluminoum case. If it did though, then very likely there would be insufficient sealing pressure on the faces of the halite washer to form an effective seal.
So, the Halite washer needs to be just thick enough so that the plate bends everso slightly when it is screwed down. This effect was easy to see on the crappy aluminium plates used in SIL engines. They would bend but wouldn't relax back to straight when removed. Consequently they would leak past the halite washer.
I don't use halite washers anymore. I prefer to make up an O-ring from rubber cord and a dab of superglue so that the made up O-ring sits around the outer periphery of the bearing. I screw the plate down and leave it overnight, pull it out again and measure the amount of compression on the rubber ring. 50% compression is good and it should be even all around the O-ring. Too much compression requires a thinner O-ring and Visa versa if there is not enough.
You can usually buy lengths of O-ring cord from your local bearing supplier in 0.5mm diameter increments.

Re: Drive side bearing

PostPosted: Thu Feb 22, 2024 4:04 pm
by Brez
I followed Stickys advice and put a dab of loctite under the head only, did do a centre pop on each just to make sure as yet untested.