Hi there, first of all sorry for my bad english, I'm french,

I am rebuilding a sc28 engine, and I have some doubts about the rods bearings colors ...

on my crankshaft, the letters are the followings : A A A A

on my rods the numbers are the followings : 2 2 2 2 (D2 D2 D2 D2)

the fact is that when I look the color of the old bearings, one of them is yellow instead of green (it's like green green yellow green)

I did plastigage the bearings and I've got thisresult :

rod 1 : 0,040
rod 2 : 0,045
rod 3 : 0,045
rod 4 : 0,045

so the results look that it seems to be good, even if the bearing color is not correct

I got this engine with no historic at all so I can't know what and why they do anything to it ...

what do you advice me ? many thanks

Your faitfully

Pascal

 

I have just rebuilt a SC28 (29) and most of the colour codes on mine were not visible, but in any case they were all close to the service limit. I would recheck with plastigauge and if the results are same, i.e. well within the 0.06 service limit, I would refit the old ones, unless you dont mind spending the best part of €100 for a new set.
On another subject is yours a SC29 or 28 ? do you still have the low lift inlet (French model) camshaft ? I have a spare exhaust camshaft and was thinking of fitting it on the inlet side , I worked out where to put the timing marks , I just wondered if you have any ideas?
Bien a vous
Bob

 

Hi bob, Thanks for your answer,

Ok it's surpizing that the colors were not visible anymore

thanks for the advice, I will check with brand news half bearings greens and plastigage everything for a second time, then I will see why it was a yellow (maybe it's a mistake from a previous rebuild or whatever ... )

I Think replace the crankshaft bearings will also reduce the risks of the low pressure oil in the rods bearings

when you have rebuild your engine, have you replace the crankshaft 10 x 9 mm screws ? or the head screws ?


for the camshafts, I had the french limiteds (100 hp and about 33 mm cams height) I have replaced them with the normal versions wich are more than 36 mm for the cams height, if you don't have the normal versions it's of course a good idea to remplace the inlet camshaft by an exhaust one, it's very easy and you don't have to worry about any timing or anything, just replace your inlet camshaft by the exhaust one and be sure that it fit exacty as the inlet before it was remove

If you inlet camshaft got cams about 36 mm, you dont have to change

my engine is a SC28 and not SC29. but I got both, and parts are interchangeable, the camshafts are interchangeable on sc33 and sc28 too

thanks and have a nice weekend

 

Thanks for the info,
I have just finished rebuilding an engine, but i didn't fit new bolts, only new copper washers, (they were included in the Athena gasket kit).
Next step is to fit the rebuilt engine into my main bike, which will keep me busy during the "confinement"
I apologise for using English but my French, especially written, is much worse that your English.
Stay Healthy
Bob

 

NP bro,

Ok, what did you done to the engine for rebuild it ? Did you changed the bearings too ?

Ok thanks, some people told me to put new screws but I was asking my self if it was really usefull ... it seems it doesn't ...

No problem for speak english, and let me know about your rebuild i'm very interested about it

Have a nice day