New formula oil for a Sherman engine

[maple_leaf_eh]

I received the message below on an email list that Hanno moderates. It is a worthwhile question to repeat here.

"[G104] current oil for GAA engine?‏

Date: 16/11/2013
To: G104 yahoogroups

Gentlemen, We are seeking a current oil substitute for the GAA we are installing in #11965. We are concerned that current oils will eat the sterling silver bearings and if no zinc is in the formula the cam bears will be compromised. These motors have Sterling silver bearings and the oil will pit the bearings.

The oil wholesaler’s technical representative was trying research paraffin based, chlorine free, zinc free current oils but no one has experience with sterling silver bearing pitting. Any suggestion and advise would be appreciated.

Thanks
Russ Morgan

[Harry Moon]

try contacting Boss Lubricants in Calgary Alberta. they make Collector automobile Motor Oil.

[maple_leaf_eh]

Rec'd from the originator:

"Thanks Terry, We are scared of these sterling silver bearings. Oil in the 40’s was paraffin based and not all the additives. Zinc was the lubricant they used for the cam bearings. Lead in the fuel was the valve lubricant. We hate to hurt this engine with the wrong oil……………..manual just says SAE 50 over 32 degrees………….SAE 30 above zero degrees.

I am afraid it might not be a question that most researchers would need to know so unless you are trying to pour modern oil in a 70 year old “ high performance” motor from the army you would not care. You are the only guy to replay with any help. If the current oil attacks the sterling silver bearings while just sitting as theorized, we need a solution if we plan to keep these running very long in the future. Thanks for your help. Russ Morgan Loveland Colorado."

[Bob Carriere]

Hi Terry

If it is a radial engine..... there must be some collective knowledge from the aircraft collectors./. restoration crowd.......

Wonder what Porter uses in his Spitfire...... or are they in the habit of retro fitting modern alloy bearings to be compatible with modern oil.

A lot of restoration magazines tech section are advocating using modern heavy duty diesel engine oil in all older (pre 60) engines for its older zinc formulation and/or adding a zinc additive ........ some caution need to be exercise as some of the zinc additive fill not flow or surevive long through a modern low micron full flow oil filter.

Or maybe they should be considering the synthetic oil invented/created by Agriculture Canada, Neatby Bldg on Carling... for WW II high output torpedo engines...... CANOLA oil....

CAN
Oil
Low
Acid

Also nice to make French fries.

Bob C

[Lauren Child]

You could ask Morris Lubricants in the UK. Their oil gets used in a lot of far older machinery over here, and I'm sure it's the sort of problem they will have encountered before.

http://www.morrislubricants.co.uk/sc...?idCategory=29