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Sigma cam timing


Eccles

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Does anyone have details of the cam timings for the 125/140/150 Sigma engines?

I'm involved on a thread on Pistonheads about this and was wondering if anyone here has any info to see if I have my 150 set wrongly?

Ta muchly - Ivan

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That's the thread, I'm the other one who's been given values of 110/110 for the 150 cams but wasn't sure if they are the same cams and am trying to find out what others know and set theirs to.

He's certainly does and he's getting good power too. Just been trying to figure out if I have been given the original specs and the thinking has changed for these cams to 111/118 or if the cams themselves have changed at some point and is the Supersport cam the same as the 150 cam *scratchchin*

Maybe I'm just thinking too much! *wobble*

 

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I think the cams are the same for the 140 and 150, Piper marked 150 on one end. From my experience, the inlet cam on the 140 is retarded a fair bit, which I  think is to do with the long inlet tract. When I  tried to advance it to a more normal figure, the engine lost some bhp but gained a little torque. I then upgraded to dthtb and the shorter inlets needed the figure around 110 to develop max bhp. The exhaust did not seem to have so much effect. Both figures could be correct, depending on plenum or throttle bodies.

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Thanks Mike that's great. Looks like I am OK with my 110 on the inlet as I have the dual throttle bodies. I never realised that you could change cam timing that much without totally upsetting the performance.

Did you have your car mapped by the two Steve's, and if you don't mind me asking, what were the power figures after setting up?

Ivan

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Thanks Tom,  looks good.

Think this thread has just cost me a rolling road session re-map the engine! *biggrin* I've suddenly got the urge to iron out any drivability lumpyness and see what else is at the top end.

Thanks all

Ivan

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