Oil pumps for 650ss

You have to go 6 start with any pump you fit for the high pressure setup.

hello let's hope it holds the oil in has normally you end up will leak from the spindle end covers, 650s and atlas were happy with 3 starts you get 60 lb with this setup, but you need in place blank shellbearings NO oil Holes In the shells bearings. with six starts you need shell bearing with oil holes this is most important..... and you need to change your pressure relief spring. yours anna j

Hello John

I would mount the commando pump and gearset as basically you have now got the commando head lubrication setup.

it dosen't matter if the rods have blank shells or oil holes, there is plenty of oil getting supplied to the bottom end with this setup. the relief valve will take care of any over supply (thats its job)

When i rebuilt the bottom end on my mk3 commando i reversed the conrod shells to blank off the oil holes. These holes are in the perfect place to bleed off the hydrodynamic oil wedge pressure needed to prevent metal to metal contact. Don't worry about cylinder lubrication, there is loads of oil getting flung out and being thrashed around by the crankshaft, this is what lubricates the cylinder walls.

Have a look at the Carrillo rods for commandos, i'd put money on that they don't have the oil bleed holes.

Regards

Peter

On an early 650 you will have a Mag or points unit behind the Engine,if the Pressure release valve gets too busy you are likely to find oil and ignition are not happy together. The smaller oilways will struggle to cope with the flow and there will be excess pressure and frothy oil which makes for cavitation damage to shell bearings, None of these things may be obvious with light classic use but the makers Norton of Bracebridge St were good engineers and would not have liked many of the changes made by AMC.

Previously robert_tuck wrote:

On an early 650 you will have a Mag or points unit behind the Engine,if the Pressure release valve gets too busy you are likely to find oil and ignition are not happy together. The smaller oilways will struggle to cope with the flow and there will be excess pressure and frothy oil which makes for cavitation damage to shell bearings, None of these things may be obvious with light classic use but the makers Norton of Bracebridge St were good engineers and would not have liked many of the changes made by AMC.

hello yes I do agreewith these comments and Robertyou should have put Bracebridgestreet were better engineers then AMC were !!!!

Hi all,

I am interested in Peter Shand's modification - reversing con-rod shells to blank-off con-rod oil feed holes.

I have a 1968 Mercury which has all the later oil pump / oil feed mods and suffers from oil burning. The only oil control rings I have been able to source for the GPM pistons ( fitted circa 1995 ) are the one piece type rather than the later multi section rings.

Any thoughts on Peter's mod, and possible implications, would be much appreciated.

Best regards,

Chas G

hello yes you just fit the top shell with the hole in the bottom rod end cap and the blanc shell in the top, job a good do not forget to touqe up to 25-foot-pounds on each nut new nuts every time,

I've hadCarillo rods in my 650SS for about 10 years, no bleed holes, hasn't bothered it!

Maybe I'm a little dense but I don't get it.

If you block off the oil holes in the crankpins by swapping out the shells, how does oil get to the bearing journals?

Does it just seep around the edges?

Mike

Previously michael_sullivan wrote:

Maybe I'm a little dense but I don't get it.

If you block off the oil holes in the crankpins by swapping out the shells, how does oil get to the bearing journals?

Does it just seep around the edges?

Mike

Hello michael . if you swop the shells over the oil will simply exit as you say around the edges . alls it will do is block off the conrod oil hole that sprays up the bore. the crank will be fed oil normally.

Barry