From: "Rudnicki, Steve" <Steve.Rudnicki@gdcanada.com>
> So while the oil line looks cool, I don't think it adds value and
> in fact is potentially detrimental as it robs the main bearings
> of oil.
I agree for the most part. I have not seen any engines that we have torn
apart or built and maintain where the use of the external rocker oil feed
line has robbed the main bearings of oil. I have heard the same thing said
about robbing the cam journal feeds of oil, and I have not seen this either.
Using the rocker oil feed line on the stock rockers is a waste of moeny. As
others have mentioned, if your engine is in good working order and the
passages are sludge free, you should have plenty of oil reaching the rockers
through the length of the rocker shaft. That said, the rockers at the front
of the motor (opposite end of the oil feed) definitely see less oil.
Certain roller rockers, like mine and Richard Good's, have internal passages
in the aluminium rocker body to feed oil over to the needle roller tip and
pushrod cup. I do recommend the use of the external oil feed line to help
supply the necessary oil to pressurize these additional passages and make
sure oil is reaching the roller tip especially.
Also, for those of you buying nitrided or tuftrided rocker shafts. Make
sure you clean them out internally before use. I have seen too many of
these shafts that come through with quite a bit of debris inside from the
oil quench bath that they go through. There are only a dozen ways for
debris to get out of the rocker shaft, and each of those ways is through the
feed hole at the interface of the rocker body pivot bore and the shaft.
This debris will cause a reduction in the amount of oil the rockers see. As
with a block during a rebuild, spend the time to clean all of the oil
passages extremely well.
What about oil burning? Never a problem on my engines, viton valve stem
seals keep the oil from entering the guides. The excess oil drains to the
lifter gallery, which aids in the lubrication of the cam lobe / lifter
faces, especially when using lifters with oiling holes.
What I would love to see, and maybe what I'll try in the future sometime, is
to run a smaller feed line to the front of the rocker shaft in order to try
and equalize the pressure and flow of oil the entire length of the shaft.
Someday... like half of my other pet projects.
Kai
--
Kai M. Radicke
Wishbone Classics
www.wbclassics.com
Ph: 215.945.7250
|