Pagoda SL Group

W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: t.h. on January 29, 2010, 06:54:14

Title: cylinder head rockers
Post by: t.h. on January 29, 2010, 06:54:14

does any one know what the rocker arm ratio is on a 130 engine please

Title: Re: cylinder head rockers
Post by: ja17 on January 29, 2010, 18:36:49

Hello t.h.

I am not sure what you mean by "rocker arm ratio" ? 

Title: Re: cylinder head rockers
Post by: t.h. on January 29, 2010, 21:29:36

Hi The ratio is determined by where the camshaft is positioned in relation to the length of the rocker arm.
Example is if the cam is positioned directly above a vavle the valve would only open as much as the lift on
cam lobe is but as you move move the cam along the rocker arm towards the pivit post it increases the
amount the valve opens.
I have seen the figure somewhere but buggered if i can find it and i need it for the engine shop as the head is being
flowed modified if required and ported and polished

Title: Re: cylinder head rockers
Post by: jeffc280sl on January 29, 2010, 22:23:05

Isn't the rocker ratio created by dividing valve lift by cam rise?

Title: Re: cylinder head rockers
Post by: ja17 on January 30, 2010, 02:10:22

Hello th,

Thanks,.......... interesting.  Let us know how much difference the modification and flow work does on the head.

Title: Re: cylinder head rockers
Post by: Benz Dr. on February 02, 2010, 05:14:35

I have the flow bench results for a 250SL head. They're much beter than you might think and are about the same as a typical small block chev. The guy who did it was very impressed and it was a dirty old head with crud all over the valves.

Rocker geomerty is critical on these engines. Get the rockers out of whack and you can ruin valve guides in to time at all. Less than a few miles if really bad.