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Mototrans Cam Timing

Posted: Wed Feb 05, 2020 3:42 pm
by Duccout
Hi, I am new here, but some people will know me from other forums. Pleased to meet you all!

I have just bought a Mototrans Strada 250 and I'm a little puzzled by the camshaft part number; the parts book lists it as 0603.29.10 which is the Ducati cam that is coded grey, with figures of 62/76 and 70/48, but the Strada manual gives the timing as 68/95 and 84/78; so what is correct? Did Mototrans just use their own grind and give it an existing Ducati part number?

Can someone tell me if a narrow case cam can be used in a wide case engine? If they are different how does one tell them apart, is it simply by looking at the differences in the base circles?

Thanks.

Re: Mototrans Cam Timing

Posted: Wed Feb 05, 2020 9:30 pm
by Jordan
250 & 350 use the same heads, and are interchangeable across narrowcase and widecase engines, according to a comparison of parts lists.
Part numbers for heads carry over from certain NC models to certain WC models.
So it follows that if a camshaft fits a NC, it must also fit a WC, at least for the 250/350s.
Jim Pianetta has produced data comparing several camshafts fitted to Ducatis.
https://www.ducatimeccanica.com/
Search "Pianetta" on the website.

Re: Mototrans Cam Timing

Posted: Wed Feb 05, 2020 9:53 pm
by Eldert
Hi Colin

welcome aboard . the Mototrans guru on this forum is Jon Pegler
he will chime in sooner or later to answer your question .

Eldert

Re: Mototrans Cam Timing

Posted: Thu Feb 06, 2020 10:26 am
by Jon Pegler
I fear Eldert does me too much credit, as I do not know the answer to your question.
Both the Forza and Strada parts books and handbooks give the cam timing figures as 68/95 and 84/78, but the parts book claims it is fitted with the grey cam, 0603.29.10 with the different figures that you quote.
Having measured many Mototrans cams with a degree disc I have found that almost no two are quite the same, so Mototrans may have claimed a grey cam was fitted and then just ground cams as they wished.

If you propose fitting an Italian cam, bear in mind that the later Mototrans cams had the keyway for the drive gear cut in a slightly different position to the Italian cams.
This required the lower bevel gear to be aligned one tooth later than most Italian machines.
The majority of Italian machines have the lower bevel timing dot aligned with the keyway on the gear, whereas the Spanish lower gear has one or two dots, of which the LH dot is used.
This is not really a problem but it means that it is essential to check the cam timing with a degree disc and not just rely on the various timing dots. I always check the opening and closing degrees of the cam when assembling motors as a matter of course, especially as many of these engines are 40 or 50 years old and can contain any number of non-original parts after all this time.

Jon

Re: Mototrans Cam Timing

Posted: Thu Feb 06, 2020 10:37 am
by Duccout
Hi Jon,

Thank you for the reply, most informative, and I was thinking of going for a 'softer' cam. Just goes to show that nothing can be taken for granted when comparing Italian and Spanish builds.

Colin