Camshaft oil groove question

[gtblast]

I am rebuilding a stock 1970 1.9L for my GT. The stock solid lifter camshaft has an oil groove that goes about 3/4 around the front bearing journal. I noticed that the later hydraulic cams have an oil groove that goes all the way around the front bearing journal. Before I reassemble this head, is there any advantage to cutting the stock solid lifter cam to have an oil groove all the way around? Might this improve oiling to the lifters and rockers?
Fred

[markandson]

Check this post by RallyBob from another thread

[trlmr]

I think if you buy an aftermarket cam for solid lifters they have a groove that also is cut the circumference of the cam like the hyd cams. So it must not be a bad thing. My memory may be a little foggy on this as it has been a while since I saw one. I'm sure someone else is in the process of rebuilding a motor or has recently done one and can shed more light on this.

[gtblast]

Originally Posted by markandson Check this post by RallyBob from another thread

I had read this post, but it has nothing to do with my question.

[gtblast]

Originally Posted by trlmr I think if you buy an aftermarket cam for solid lifters they have a groove that also is cut the circumference of the cam like the hyd cams. So it must not be a bad thing. My memory may be a little foggy on this as it has been a while since I saw one. I'm sure someone else is in the process of rebuilding a motor or has recently done one and can shed more light on this.

Yes, I am thinking it must be an improvement. I have read countless threads looking to find where someone had already done this but could not find any.

I just wonder if there is a technical reason that the solid lifter camshaft has only the partial groove. If you look at the groove shape, it could almost act as a pump as it swept by the oil holes in the front bearing and cause the oil supply to the lifters and rockers to pulse. I would think that with the hydraulic lifters you would not want that pulse and would want a constant pressure, hence the full groove. Just a thought.

[GTJIM]

Yes - the partial groove in the earlier solid lifter cams meters the oil to the lifter gallery and rocker gear as the solid lifters do not require a constant oil pressure to operate like the hydraulic ones do.
It is not necessary to complete the groove unless the originally solid lifter cam is used for a hydraulic re-grind - then the groove needs completing for correct hydraulic lifter operation.

The later 2.0L oil pathway is even more positive than the fully grooved cam front journal as the oil constantly flows around the outer surface of the cam bearing in the head and makes sure the lifter gallery is under constant pressure - even if the cam bearing itself is factory installed a bit out of line. This was specifically for hydraulic grinds, to ensure oil supply - but solid lifter cams can be used too.

Constant evolution - or 'intelligent design' !!

Either type of cam with different front journal grooves can be used for a solid lifter re-grind BUT the later cam without a groove can only be used in the later head with the oil supply groove around the outside of the cam bearing - or else the lifters and rockers will not receive enough lubrication even for solid lifters.