K10 Ma12 Autograss Class2

[dennehys]

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dose any body know the inlet and exhaust opening and closing degree before and after tdc.its in the service manual but i cant find one.its for a autograss class 2 racing car,part of a final year mechanical engineering project.

 

[bobsp16]

ive been racing these for 6 year now and dont even no that.as we are only aloud to use standard cams and timing

 

[Fordy]

ill see what i can find at work but im not guarantying anything

 

[dennehys]

ill see what i can find at work but im not guarantying anything

for the 1 litre micra the inlet opens at 11 degree and close at 45 degree,and 7 and 51 for exhaust,
its these values for the 1.2 im looking for

 

[bobsp16]

for the 1 litre micra the inlet opens at 11 degree and close at 45 degree,and 7 and 51 for exhaust,
its these values for the 1.2 im looking for

i would think there the same cus ive none other people to swap and try them between the 2 engines and have'nt notice any change

did you found out these values on the ma10 by using a dial gauge and cam deg disc the same applies with the ma12

 

[dennehys]

i would think there the same cus ive none other people to swap and try them between the 2 engines and have'nt notice any change

did you found out these values on the ma10 by using a dial gauge and cam deg disc the same applies with the ma12

the cam lobe size in the 1.2 is slightly higher than the 1litre.
i have the service manual for the 1 litre and its in that so im looking for the 1.2 manual.iv measured the 1.2 inlet and exhaust lift but i want to confirm my values

 

[Fordy]

ok heres what i got from the manual






hopes this is usefull

 

[dennehys]

thanks a million,there the exact figures i was looking for

 

[Fordy]

so which cams better, could you post up the figures so we can compare them

 

[crogthomas]

cams

Looking at the figures given, assuming that they were measured in the same way, the 1.2 cam has a duration of 232 degrees and the 1.0 cam has a duration of 236.
Fordy, could you get the cam timing figures for the 1.0 engine in the same format so that we could be sure?
We also know from measuring the cam lobes that the 1.2 cam has a higher lift by about 0.1mm (at the cam, not valve).

Common engine tuning myth has it that a longer duration cam will move the torque higher up in the rev range, which is the case with the 1.0 engine.
But the lift is slightly less so its debatable wether you would actually see an increase in power using the 1.0 cam over the 1.2.

The difference is so small that it would probably be almost imperceptible.


Craig

 

[Ed]

Cams should always be measured in this way. Its not a myth that long duration lift the power range either. However as you say may be compromised by a lower lift. However too much lift will ruin airflow speeds and will result in less power. It does show that a nice margin of gain is available here. I may get a regrind done just to see what differences it makes.

 

[Ed]

Bob a thought for you, would you be allowd to use turbo cams from the MA09ERT? as yet I dont know their specifications, but I may put them in a K10 just to see what they do. They have a totally different powerband to any other K10 spec I've seen. (power still going up on mine when I hit the revlimiter at 7K)

 

[bobsp16]

Bob a thought for you, would you be allowd to use turbo cams from the MA09ERT? as yet I dont know their specifications, but I may put them in a K10 just to see what they do. They have a totally different powerband to any other K10 spec I've seen. (power still going up on mine when I hit the revlimiter at 7K)

standard cam only but send me one ed and i shall try it

 

[Ed]

sorry, I dont have one I can spare! They are like gold dust! but if I can find out the timings etc Ill let you know..