Originally Posted by
senna555
Seems to be alot of jpr03 talk and I had a couple of questions that I could not get an answer.
However when I look at r9/r7 I can not find similar nova crank or p/s set. Is it based of 35 plus?
All Nova (based) sleeves have an outside diameter of 19.5mm and will fit in any Nova based engine. I know RB is the only one with the location-pin in the upper edge placed on the other side but with a dremel a small sleeve is simple made to place the cilinder in the right way. Also the crankpin of RB is a tiny bit bigger than Novarossi but it is obvious you should use the conrod fitting the crankshaft..
So far I have seen are all intakes are almost the same. OK there are some minor differences in timings but there is no one that will give a bad running engine.
The only big difference you will find is the thickness of the upper edge on the cilinder, that edge can be 1.5mm or 2mm so you have to be sure the real head clearance is set to 0.6~0.7mm.
Other difference is the height of the exhaust port, normally for an onroad engine that is arround 7mm (from BDC to closing) but with the 35+ it is lower giving a better bottom power.
All crankshafts have almost the same timings so I expect no real issues.
I have puzzled some engines together with several parts (keeping piston with its sleeve) and all were running OK.
So yes, if you want a replacement P/S set for your expensive engine you can choose a cheaper one like the Kangaro, 321 or even N21-7T