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+--- Thread: Camshaft bush oil way bore size. (/showthread.php?tid=3769)
Camshaft bush oil way bore size. - Colin Wilks - 14-01-2020
I am reworking the camshaft fixing bolt on my bog standard splash fed '33 RP.
The standard oil way drilling in the bush is 3/16" (assuming mine is a standard item). I have been advised that 1/32" is a better size for this oil way, which seems mighty small to me.
Interested to know other's custom and practice before I start drilling. I plan to have a standard assembly, so will not be embedding o rings fore and aft. End float will be approx .001".
RE: Camshaft bush oil way bore size. - Chris KC - 14-01-2020
Colin, you can certainly take this down to 3/32" without much fear. I suggest one thing to consider is whether you run an in-line oil filter or not; if there are larger particles floating around you run the risk of blocking a smaller orifice.
1 thou end float sounds a wee bit tight to me - I think the companion suggests 0.002-0.004".
RE: Camshaft bush oil way bore size. - Ian Williams - 15-01-2020
Agreed, 3/32 and don't run less that .002" cold or the cam will seize in the bush as the engine warms up, i suggest that you restrict the rear cam bush as well.
RE: Camshaft bush oil way bore size. - Colin Wilks - 15-01-2020
Thanks for that gentlemen. Woodrow quotes .002" endfloat, so that will teach me to work from memory!
RE: Camshaft bush oil way bore size. - dickie65 - 15-01-2020
Hi,
The smaller orifice is used on full pressure engines running at around 60 PSI oil pressure, this is to restrict the oil loss via the camshaft bush and to direct more oil to the Big Ends.
RE: Camshaft bush oil way bore size. - Bob Culver - 16-01-2020
On low pressure engines the trench to front of bearing and groove in timing gear must be retained as oil feed for the gears. To cure the considerable leakgae around the oil hole I used to just build up the bush exterior in vicinity with solder .