Center lube cams

[tadd]

I've heard from several major builder folks that the cam oiling from the center lube design, well, sucks. I'll be running spray bars in addition to center lube cams a la 935, just for 'insurance' cause the experts are experts and their concerns.

That said, anybody care to take a moment and explain why two large rotating holes per lobe is 'horrible crap oiling', direct quote , compared to three smaller fixed location nozzles? The rockers pivot on oil splash.... A splash is a splash? Direct application of oil to the rocker pad thru the base circle seems like a really good idea... What am I missing?

One can search and find the nasty results from a clogged spray bar hole, but I've never found carnage pics from a solex or race motor. The holes in the cam are just huge. I just can't imagine one of those getting plugged short of a bolder. I figure it's due to numbers, there just weren't many center lube solex cars and race cars, but still...

Thanks in advance,

t

[cgarr]

How is the rocker shaft oiled?

[Flieger]

I dunno, but the 917 and 908 and such used that method. The 917 even had a centerlube crank, which we all know allowed for lower, and nearly constant wrt rpm, oil pressure needed for the same lubricating film strength than a 911 type oiling system. Spray bars make sense for gears, but for cams where the friction is only in one place I suppose either is fine. The 917 had on demand oiling where the oil only went to the tappet starting when the tappet was being depressed. So, if you had a cam lobe flinging oil all around then I could see it not being so good as a spray bar directing it only to the critical area.

I have not seen the centerlube cam system for a 911 so I'm just guessing here.

[Henry Schmidt]

Originally Posted by cgarr

How is the rocker shaft oiled?

The center feed cams spray oil profusely so the entire interior of the cam tower is flooded with a heavy mist of oil.
The rockers are splash fed with the mist flying round in the cam tower.