Please enlighten me on Green Dot Pulleys.

[mpesik]

Hello. Been reading for awhile and green d.p's keep coming back.

What makes them different than stock ?

Thanks

[CarBuff]

The Mean Opening Point or MOP.

 

The dots are indicators of the MOP, which is a timing parameter.

 

The Green pulleys are 104 MOP, the other colors are slightly different and are used in emissions localities (like North America).

 

But a 104 MOP pulley on both the intake and exhaust cam wheels optimizes power and low end torque.

 

+++++++

 

Look at the backside of the I & E pulleys with the engine off, usually the dots stop fairly close to pointing at each other.

[mpesik]

Thanks.

You seem to be everywhere. lol.

Have a good evening Atwell. 

Best.

Mike

BUT  !!!

I still don`t know why green dot pulleys are better than stock.

[Escape]

The answer is timing.

The camshafts used in the Lotus 910 engine are designed for MOP 104°. For emission purposes, later engines are actually timed differently, by using different pulleys (100°/110°, blue/red dot). This results in sub-optimum performance. With the 104° green dot, the timing is as it should be, and performance a bit better than stock.

 

I have fitted green dots to my engine, but with the engine still out of the car and can't comment on the effect as of yet.

 

Filip

[jonwat]

The Mean Opening Point or MOP.

 

And there's me, all these years thinking it stood for Maximum Opening Point. 

[dodge1979]

Shame on you john..everyone knows its when the cams are being their meanest towards the valves and pushing them away as far as possible..I mean..no pun..the cams are just bullies..constantly hitting them defenceless tappets n valves. .