How much power would a person lose on a solid roller motor if their lash was extremely loose....say .045 versus .023?

Could that loose of lash make the cam seem much smaller and cause power to drop off earlier in power band as well?

Dave

 

damn dave we ran .14-.18 on the sprint car stuff

yes tighten those bad boys up and see what happens

 

When you get that much lash you have effectively eliminated the ramps that take up the lash and you are slamming the cam into the lifters on the opening side and slamming the valve into the seat on the closing side.

That probably leads to a engine that doesn't make much power and has a short life expectancy. Could be a tad noisy also.

 

would loose lash cause you power band to fall down too, like say power falling off at a lower rpm?

 

I wouldnt even try .045"....as OldSStroker said, you are going to do some damage with spring pressure and weak valvetrain control. That is alot of slack to be taking up at rpm with that kinda pressure.

I picked up .3 sec and 2 mph at the track from going to a .026" hot to a .013" cold (~.015-.016" hot). No other changes to the car, temperature was 5 degrees cooler on the day I went faster, with slightly higher humidity. Even on the street, my cars have always "felt" significantly faster with .010" tighter lash.

I actually run all my SR motors with a tighter lash than recommended by the manufacturer. And yes, looser lash WILL cause power to drop off at higher rpms sooner.....that is the most noticeable difference.

When the car feels slower and the valvetrain gets louder, its time to tighten up the lash.

Jason

 

My cam supposed to be .016 .018, and thats what i adjusted mine to about 3 weeks ago, but my car is falling on its face at 5500rpm. I am going to re-adjust on saturday and take it to the track sunday. Any chance the springs could just be weak? Sorry to hijack your thread.

 

could be springs....what springs do you have on the motor and how many miles/usage? Obviously check the lash too.

Jason

 

The car has probrably seen 80-90 passes and probrably 3k miles on these springs. I do not know which springs they are, but i do know they are the right ones. I bought the springs from the person(bauer racing) who designed the cam. I will be putting new springs on over winter just to be safe. It doesn't cost much $$$ and its worth the insurance. My PTV clearance is tight and i would hate to float a valve.(bauer racing)