Larry Quirk wrote
>Whilst rebuilding a 70 GT6 2.0L cyl head, I have installed bronze guides
>and new valves. Upon assembly, a lubrication hose will be used to bring
>additional oil to the rear of the head. Has anyone had experience with
>pumping additional oil to the rockershaft in this manner and should guide
>seals be installed to prevent excessive oil draw past the guides once they
>start to wear? The local machine shop suggests using VW viton seals >and has
>a tool to machine the guides for these after pressing them into >the head.
After I rebuilt my 2500 engine, I put this mod on and it made an incredible
difference to the amount of oil getting to the rocker gear. (I could never
figure out why the increase was so great since the original delivery holes in
the block and head appear that they should be adequate).
My engine is in very good condition with new valve guides but without inlet
seals and there was a noticable darkening in the exhaust pipe colour although
no visual smoke or measurable increase in oil consumption.
I'd put seals in if I were you.
One problem I encountered was a leakage of oil from the back of the head via
the head gasket. Presumably my head is not true at that spot and since the
feeder hole is so close to the edge, the extra oil (and pressure?) found its
way out. There's a hint of a leak without the extra feeder in place.
If I have cause to take the head off, I might block the existing feed holes in
the block and head and use only the remote feed pipe.
Regards,
Bob Hutton
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