Cupcar

One thing I noted is that the stock 993 spray bar has a restrictor built into its feed end that has quite a small hole. I think this may be to help pressurize the hydraulic lifters on start up as well as lower sprayer flow since oil will be spewing from the pressurized rockers which no longer need to be sprayed for lubrication anyway.

I used the rocker shafts from Patrick with the small hole along with 930 adjustable rockers and also drilled the spray bar's restrictor to a larger diameter figuring that the extra oil spray would help cool the valve springs. GT3 pump and so far so good.

JoeMag

Groove in bushing…