I have had to remove the oil gets from my crankcase because they were both damaged although one is suitable for a pattern. I could not locate any new ones so was going to make a pair.
Does anyone know what size the hole should be? We are advised to use a 1/16 wire to clean them but the one I have has a 5/64 hole.

Did the 3-bearing engine jets have thinner holes? I have several sets of these new jets, so they will need drilling out. The Source Book (p. 450) mentions that from 24/3/37 (Engine No. 269660) the oil-jets were increased to 3/64" diameter.

David

The book does indeed say increased to 3/64 and I wonder if this is a misprint for 5/64 as 3/64 is less that 1/16

You can buy new oiljets at the7 Workshop. 01225868696

As far as I can recall, the jets on 3 brg. engines are a smaller bore than on the 2 brg. I presume this as done in an attempt to get a better oil flow to the centre main.

Regards, Stuart

Brian,

In my spreadsheet i put together working out the right size oil jets to go with an enlarged pump to get the same oil pressure as a standard system (see earlier thread) i have standard 2 bearing jets down as 3/32". This would make sense as the jets were then decreased in size to 5/64" for the 3brg.

For an enlarged pump at +0.045" the jets need to be 7/64" to get approximately the standard oil pressure (so you get higher flow and can use the original oil pressure gauge). 7/64" is as big as you can go and still fit the jet through the 1/4BSW thread in the crankcase, i am considering drilling the threads out to use wire thread inserts and fitting even bigger jets before the insert is installed, i will also use a modern gerotor type pump.

Regards

Rob

Many thanks for that Rob; that would mean that my existing jets are too small at 5/64. That still leaves a puzzle as to why only a 1/16 wire is recomended for clearing them out.
Regards
Brian

.

Probably only a sixteenth wire in order to get around the bend if the tubes have been bent when aiming them.


Mike