MoTeC on Aprilia SXV550

[NeoViper]

Hi guys,

wondering if anyone has used a MoTeC on an Aprilia SXV 550 before?

from my understanding, timing on a MoTeC ECM is governed by the REF and SYNC pulses.

however, the 30-2 REF pulse is attached on the rotor of the generator, which is then attached to the crank via a sprag clutch. (please correct me if I'm wrong on this...)

the SYNC pulse is generated by a Cam sensor that was added on one of the two cylinders.

considering that the cam shafts and the crank shafts are in sync, doesn't that mean that the REF and SYNC pulses can go out-of-sync at any time, and the "CRIP" angle will just keep changing?

on a side note, we are intending to lock up the Sprag clutch, permanently linking the rotor of the generator (with the 30-2 teeth REF signals) to the gear linking it to the crank shaft so that the CRIP stays constant. would that cause any damage to the engine?

Thanks!

[Jimmy01]

I have not looked in an Aprilia engine before but the sprag clutch should be for the starter motor gear train. If you lock this up your starter will spin at 1,274,857,383,686 rpm when the engine is running. This is not desirable.

The crank trigger will definitely be attached solidly to the crank shaft.

[jordan.k]

The crank trigger on an Aprilia is not connected to the crank via the sprag clutch. The 30-2 trigger wheel is connected as part of the generator housing, but the sprag is connected to the starter motor. If you are looking at getting an Aprilia going for the first time be careful on the starter and don't crank it for too long without letting it cool off. I would also suggest purchasing a spare starter and sprag before they go out. Rick's Motorsports Electronics will rebuild your expired starters for you.

[NeoViper]

I see... Got it!
thanks! will take a look at it more carefully again.

[DOA]

Hi there

We have used this engine for the past few years on a Motec M400 ECU. As much as you can say these things are easy, its quite an easy engine to use since it is already Fuel injected so everything is there for you already but as said by racerk13, the starter system is VERY unreliable (and in my view so is the entire engine although its hard to argue with the power and torque curve you can get from the engine considering its weight)! I know we bought some upgraded starter motors and I will try and find out where we sourced these from but make sure and get a spare sprag clutch or two as well as they are just as unreliable as the starter motors. One small piece of advice I will give you is to make sure that wherever you mount the engine in the car, make doubly sure you can get to the starter motor easily, they really do fail that often!
This may seem a bit obvious, but make sure, whatever you do, that you get someone who knows how to build engines to do the work on it and double, triple and quadruple check that everything is done properly and to the manual as we have had a series of failures due to a number of reasons relating to the build process and these are very finecky engines!

PS, where are you based? I am at Uclan in Preston UK.