Motoscrubs.com

AFAIK, all early cams had a drilling right through the camshaft, to allow for lubrication of the rockers, lobes and top bevels; my knowledge of Singles then runs out, so I don't know if Bologna ever fitted roll pins into the threaded end of the Singles cams, but I do know that from about 1980, all vee twin camshafts were fitted with roll pins in the threaded end and given different part numbers. Also AFAIK, aftermarket cam manufacturers never drilled their cams all the way through, because they believed that the top bevels get plenty of lubrication from splash.

This doesn't solve the question of why Mototrans fitted a roll pin to the feed side of the cams.

This doesn't solve the question of why Mototrans fitted a roll pin to the feed side of the cams.

Hi

Maybe they didn't - perhaps someone (a previous owner) thought that this would be a good idea.

I have two Mototrans bikes, and both had a roll pin in the threaded end of the camshaft only.
I would definitely remove the one at the feed end.

I suppose that a previous owner could have fitted the roll pin in the feed - maybe it was an attempt to stop the oil leaks!

Pertaining Motortans and the pin the the cam; mine has a factory installed oil pressure switch and accompanying idiot light on the dash. I imagine the pin is a feeble attempt to get enough back-pressure to activate the switch.

It looks the part, but doesn't work well of course.

I think that you've cracked it Rhys! My Strada also has the oil pressure switch, so I reckon that you are right. Hopefully Jon will confirm that engines with the oil pressure switch had a roll pin in the feed side of the cam. Anyway mine now has a Bologna cam, so no roll pin in the feed side.

I am on my first Ducati engine rebuild, so still taking things onboard, I don't know if this apply, as it's not a Mototrans engine, but would assume they have the same arrangement, the dowel at the head joint has a 2.2 MM hole, this is obviously somewhat of a restriction on the feed to the camshaft, compared to the size of the gallery.

The roll pin should be at the bevel end of the camshaft on Italian engines (I have no experience of Spanish engines) the roll pin somewhat restricts the oil flow through the camshaft forcing most of it through the cam lobes and on to the rocker pads. Desmo single's either have a solid plug at the bevel end of the camshaft or a plug with a very small drilling in to act as an oil jet for the bevels/ tachometer drive. A standard mod on race singles is to plug the cam as in the desmo's.
Cheers,
George

Head off again to attend to oil leaks! I am not surprised that the oil banjos were leaking; Nigel suggested that they may have the surfaces dished in, and did they! In addition to which the plating had flaked off leaving an uneven surface. I have redressed the surfaces on an oil stone and am hopeful that they may be OK, but if not a new pipe may have to be found.

I prefer these:


https://www.usit-ring-shop.de/epages/10228732.sf/en_GB/?ObjectPath=/Shops/10228732/Categories/%22Usit%20-%20Ringe%22
They are avaiable in std. NBR rubber, FPM(Viton) for higher tempratures, and more. And - you can re-use them several times.

Hans

Thank you Hans, I will investigate further! I assume that the rubber centre is compressed when the bolt is tightened and this seals the banjo?