Crankshaft Exchange
 

Lets see who can help me with this one....

I'm rebuilding my old RB X12 310 engine using different parts i got a hold from different Nova based engine:

- P/S and conrod Novamega ABC 2134 race MS
- Crankshaft Novamega 2148 from the SX RE EV1 2103T MS engine (3 turbo scoops, 1 front 2 rear)
- JP Racing carburator.

My question is... what performance difference do you get from a full circular crankshaft, like the one i'm getting, vs a delta or half delta shaped crank like the one the original RB had??

Your comments will be appreciated

AFM

Hi:

First, you cannot fit a NovaMega sleeve into an RB/Nova crankcase, because, the locating pin on the crankcase is on the exhaust side on RB/Nova and on the Boost port side in the case of the NovaMega, don't know why, but MS has assured that in a Mega, only certain original spare parts can be fitted.

You can fit it if do a cut on the sleeve and pray for doing well at the first try and have all the ports correctly located in the channels of the crankcase.

Regarding crankshaft, you will lose performance, RB has been quite agressive on the timing of the Rody units (are balls out race engines, not for the puny).

A full circular crankshaft can have some advantages in the case of guiding fuel to the ports, as the trailing part of the crankshaft still squirts fuel and air to the ports, but have to have a correct cut to do this. Rather than this, I don't see more advantages unless weight wise, S1 and MicroCasted pistons (NSR/RR models) are slightly lighter and creates a little more shake on the the engine at certain speeds.

This last cannot frighten you, is IMPOSSIBLE, NO MATTER WHAT they told you that a monocilinder engine is completely balanced unless have some counter rotating axle that removes the shake, you can adapt a little the weight on the bob of the crankshaft, but you need to have at hand some kind of crank balancer and isn't a readily available machine unless you have at hand an engine shop. But CANNOT BE COMPLETELY balanced, you're forewarned. :D

[QUOTE]Originally posted by Corse-R
[B]Hi:

First, you cannot fit a NovaMega sleeve into an RB/Nova crankcase, because, the locating pin on the crankcase is on the exhaust side on RB/Nova and on the Boost port side in the case of the NovaMega, don't know why, but MS has assured that in a Mega, only certain original spare parts can be fitted.....

Regarding crankshaft, you will lose performance, RB has been quite agressive on the timing of the Rody units (are balls out race engines, not for the puny).......

Thanks Alfonso (Mi nombre tambien es Alfonso......o sea que somos tocayos jajajaja).

Somebody gave you wrong info regarding fitting of Novamega sleeve on RB case...It does, I allready assembled the engine with now problem at all, I did check with blue paste that all ports match precisely to the case and didn't have to correct nothing, it was a perfect match
Also I've checked different Nova based rear exhaust sleeves from different engines, and they all fit in between, but needed in some cases to match exhaust port to case (widht).
If they are from side exhaust engines, then they don't fit because, as you said, pin guide cut is on opossite side.

Regarding the crank, i did measure the timing(degree wheel)on the original RB crank and copied on to the Novamega crank.

Today I finished my bench 4 tanks break-in, next week I'll finish track break-in and.....see how it performs...I'll post results when tests are completed and compare it with my Sirio Evo 2, with which I set a new track record last week. By the way I bought that Sirio from Azor Modelismo in Madrid...great customer service.

AFM