500 main bearing

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pedro
Posts: 311
Joined: 04 Nov 2010 21:14

500 main bearing

Post by pedro »

Does anyone have any numbers or possible replacements for the 500 LHS main bearing, the one with a split inner race?
They seem to be unobtainable.

Thanks

Pete
AntietamClassicCycle
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Joined: 15 Oct 2012 15:03
Location: Rohrersville, MD, US
Location: Rohrersville, MD, USA
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Re: 500 main bearing

Post by AntietamClassicCycle »

If it's the same dimensions as the 350 bearing, the one I bought was an SKF QJ306MA/C3.
pedro
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Joined: 04 Nov 2010 21:14

Re: 500 main bearing

Post by pedro »

Don't think it is, but thanks anyway.
harrymuffin
Posts: 292
Joined: 07 Apr 2014 16:06
Location: west midlands

Re: 500 main bearing

Post by harrymuffin »

Dear Pedro,
Just to puy your mind at rest regarding the substitute drive sside ball bearing for the 5oo+ engines, I sold the correct bearing aerlier this year as I bought the last one available from NLm a long time ago. However, on talking to Ade Crimp about this 'no longer available ' bearing owing to his position at Bristol University when the SKF rep. paid him a visit he explainded the dilema that Morini owners were in. I had mentioned to Ade that there was an alternative 'get me out the shit' by using another bearing with split inner race that could be ground out to the original dimension, it being a four piont angular bearing, the difference between the bespoke and this one was that alternative had one less ball in it. The rep went away and looked into the problem and did as suggested with this modified standard bearing and turned it into a Morini bearing it even has it's own part number so that you can go into any stockists and give them this number and they would be able to order it for you.
The bad part of this tale is that in my correspndence with Ade, I have lost the new bearing part number, I do have it somewhere but it is not helped by my computer hard drive giving up the ghost and although I can find references in my note books cannot find the actual number reference, but I know it is somewhere and owing to the laws of serendipity, as soon as I stop lookind will find all the information for you, or someone will have it already.
Do not forget that the gearbox also had a Morini special split input bearing, which I think also went obsolete, I think I did have one of those too but sold on with the crank bearing.
Hope this has jot made you too despondent but I have an engine where I have to modify shell bearing from two diferent engines to make up a set. Just to remind you on th shell bering for the big ends, The bearing fitted to the FIAT original 500 engines can be used and have done a couple of engines when I found out what NLM wanted for half a Israelie bearing for. Again, you have to modify, the tang is on the wrong side and they are slightly wider, Ade Crimp would reduce the width, but I left them as they came thereby reducing the loading on the bearing which is at it's maximum limit. I have had a number of failed big end rebuild jobs as the owners think they can thrape the knickers off them. I will keep looking for this info for you.
EVguru
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Re: 500 main bearing

Post by EVguru »

Both the original SKF 633250 and the QJ306 have 11 balls.

Tom Farrow and I both have NOS bearings in Ducati branded packaging, with the correct Morini part number, but with 30mm ID and the bearings are marked with the QJ306 code.
Interestingly, my microfiche scan for the Camel 501 (September 87) lists the bearing dimensions with a 30mm ID. https://photos.app.goo.gl/t83Y8GyQUG6fAL556

Was the upgrading of the crank journal to 33mm really needed, or did Morini just stumble onto cheap job lot of modified bearings?
Quite a few engines have had the crank ground to suit the easily obtainable 30mm ID bearings, apparently with no problems.
On the other hand Vintage Bearings could modify the inner races for you. https://www.vintagebearings.co.uk/ball- ... r-bearings
The bearing fitted to the FIAT original 500 engines can be used and have done a couple of engines
The air cooled twin has big ends of about 43mm, so they're definitely not the ones.

Fiat 4 cylinder; 600, 600D, or Multipla, appear to be the right ones, but only 1955-60, after which the big end journal was enlarged.
These are now quite hard to find NOS. Reproductions are available, but expensive.
Paul Compton
http://www.morini-mania.co.uk
http://www.youtube.com/user/EVguru
harrymuffin
Posts: 292
Joined: 07 Apr 2014 16:06
Location: west midlands

Re: 500 main bearing

Post by harrymuffin »

Having been over to the garages dodgeing the heat of the day, I have dug out my box of new spares and the box of bearings manufactured for the FIAT engines, the box bbearing9sic0 the manufacturer Glacier B4242SAsuitablefr FIAT. I have a box of 4 at 0.10"undersize with the number S8662SA and 2 at 0.20" these have Vandervell indentifiers on them. All bearings are nominally 35mm dia. Hope this helps and not obfucates.
harrymuffin
Posts: 292
Joined: 07 Apr 2014 16:06
Location: west midlands

Re: 500 main bearing

Post by harrymuffin »

Regarding obsolete bearings, Mr Lambertini beefed up the bearings on the crankshaft and gearbox, the bearings being manufactured by SKF. The original bearings had numbers 633250C and dimensions of 33.72.14 for the crankshaft, and the input bearing for the gearbox is 633245A. I bought the last genuine SKF bearings from NLM at the turn of the century in the correct SKF packageing and sold them on recently. However, as I have already mentioned Ade Crimp in talking to the SKF rep had him modify bearings for both these obsolete bearings, the gearbox bearing is numbered 6204/22 and is obtainable from SKF in a genuine pachaging so you know it's quality and the crank bearing is 306/33. I have a letter from Ade dated 30th July 2003 advocating the perfect fit of the 'new' SKF bearing for the gearbox 6204/22. If you are in need of either then you would be best ccontacting SKF direct if you have any identifying problems, 01582 490049. I would also be inclined to purchase known quality bearings as I have been made aware NLM towards the end of their existance were buying Chinese crap and people haveing a lot of problems with some of the stuff in genuine packaging. Caveat emptor.
Regarding my previous post, I see some spelling mistakes which are not mine, I have had problems with the spell checkers insisting American spelling which throw up all sorts of incorrect spelling errors and gobbledegook.
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