I’m after more help please from those “in the know”!
Just bought (via ebay - of course) an oil junction block (with much longer pipes than the one I had) for my 65 Jubilee. Supposed to be for Jubilee/Navigator/Electra. I note there is a different size feed hole in the oil block than I already have and that it is much smaller. Anyone an idea which would be right? I could surmise that with the later 6 start oil pump then a larger feed might be necessary but I can only find one part number (22058) for the block for lightweights so now I’m confused as to which to use. If it’s the larger sized then it’s an easy fix, if it’s smaller then I’ll stick with my original and leave the hoses where they are!
Seems logical to have a larger supply hole for the 6-start oil pump - but you say there is only one part number.... I'll have to look into this whole business for you! (see what I did there....)
Thanks Andy, that would be very helpful. I took the part number as being the only one from RGM website - it’s the same as listed in my parts book and it’s the only one listed for lightweights there. I checked all their other pictures and couldn’t see any that match the small hole version.
I suppose this could have come off an early engine and Norton/AMC changed it without altering the part number?
Investigation still ongoing. As you say, the Lightweight parts list for all models, all years use only one junction block, P/No 22058.
Yet we also know that the 6-start oil pump was introduced on the Electra in 1963, so it would be reasonable to assume the feed hole was made larger. But that does not appear to be the case.
Sadly, a lot of my stuff is scattered in various lockups at the moment (as I was in the process of trying to move before the present lockdown), but I have found these two items - one from a Dominator 3-start oil pump engine, and one from a 1961 3-start oil pump Jubilee engine so far. The Dommi feed hole is 4.5mm diameter, the Jubilee one is 5mm. (I used a twist drill blunt end to test). Return pipe side on the Jubilee block shows the dangers of using to much silicone on the base gasket!
What size is the matching hole in the bottom of your engine?
More stuff to follow - watch this space.
Thanks Andy (or is that James Bond!). Oil hole in crankcase corresponds with the “larger” of the junction blocks I have and you show (between 4.5 - 5 mm). So I’ve bitten the bullet and opened out the small hole block to suit.
I’m working on the basis that the crankcase feed hole would be correct for the application and, anyway, max oil pressure & flow would depend on “up line” restrictions and pressure relief valve working properly so hopefully a larger feed hole will make no difference! I note that the block RGM show for the lightweights has the “larger” hole in it as well.
if you come across a reasoning for the difference it would be interesting to know why but I’m happy with what I’ve got/done now - your input (as usual) is invaluable!
Cheers - Bruce