Hitchcocks Forum

Oil pressure in a RE. I found it interesting as it shows the stroke of the feed oil pump. These pumps are fairly slow at 1 in 12 which I think says 1 stroke in every 12 revolutions of the engine. From what I have observed from working on these motors this is more than enough oil for the motor even with the 1 in 12 and the short stroke of the pump piston.

https://www.youtube.com/watch?v=dNNPKzxs56E

Hi, my works manual give all kinds of bumph re: pumps are 6 to 1 as they are double acting, and the pressure relief valve is set at 60psi. Which as you state is more than adequate. Incidently the pump spring should hold the cover off by 1/8inch. The only thing not shown is how many click is the correct setting for the gearbox plunger. Does anyone have that info? Vince

My 1956 workshop manual under technical data says feed oil pump speed 1/12 and return oil pump speed 1/12. Piston stroke .5 inches on both. I was just pointing out that an oil pump of this design does not have to be frenetically spinning around like a Triumph or a BSA to deliver enough oil for the RE motor. This should mean that the oil pump spindle driving teeth at these relatively slow pumping speeds should last a very long time.

Hi Binary, both manuals are correct. The pumps rotate at 1 in 12 but pump 2 times every revolution hence 1 in 6. The factory used this system on all models in various forms. As you said it works! Vince