Hitchcocks Forum

Putting the aftermarket higher output oil pump in my 350. Was also told that opening up the rocker block/head holes may help. Could someone give specifics on how to do this?
Thanks.

I have done this to the senrat alloy rockers , but never the origional steel ones .

on the semrats:

remove the rocker covers and you can see the rocker blocks , release tension on one pushrod , and remove the top half of the block , place in a pillar drill and drill a 1/16th hole thru the top and into the bearing area, counter drill from the other side to remove any swarf. replace the cap , and then do the same on cap two

by doing this you lower the oil pressure , by allowing surplus oil to flow from the top

there is an article in tech / bullet oil pump spindles , showing how to open the lower hole , however you are adding an extra on the top

Any chance of having problems from the lowering of the oil pressure?

looked up the tech notes - thanks for the heads up.
how would I know what type of rockers I have? The bike is a 2002 350

std rockers are made of steel , semrats are alloy

the bullet does not need a lot of pressure , it needs oil flow to keep cool , the rockers are the final item to be lubricated , before oil flows back to the tank.

Alan - would you drill them out if you were me?

I can't see that this mod will be a problem. The engine is rather odd in that ALL the returning oil goes back via the rocker box area. Most similar engine designs just have a T off the return feed to lube the rockers. This is good for cooling the head as all that oil carrys away the heat but does mean you could have too much pressure at the rockers; especially when cold. The rocker spindles don't actually need a great deal of lube and certainly not at any pressure. Think about exposed rocker designs which managed with a squirt every now and again.

I would personally keep the std pumps , and leave the rockers alone (you do not need high pressure), however if your pumps are faulty , then by all means get the uprated ones with the top end mod

uprated pumps? ......... Why? ....... For what purpose? ... the top end is greatly over oiled ............ unless the feed pump is uprated to match then the scavenge pump will be pushing air most of the time ........ so you up rate the feed to compensate .... here we go nearly full circle ... why? .... for what purpose ...... is some something broken that it has to be mended? ...... That's me just being curious

Beezabryan , the uprated pumps are supplied in pairs , so extra oil would be pumped by the feed pump , but as I said last night , and you have agreed this morning , why change them (they look a good upgrade compared to std indian pump prices)