Re: [HSS] oil pump and pressure

Unknown

hudsonxx wrote:

>

> I have now surrendered the gear pump which was retrofitted to my car

> and I am in the throws of making some internals for the original. I

> suspect that the previous custodian changed the gauge to one that

> would cope with the gear pump. It reads in PSI up to 80 lbs. This

> unit is unlikley to register the performance of the original pump so

> can anyone help in sourcing a servicable replacement or advise as to

> what pressure the pump should deliver so I can try and recalibrate

> the present one. I have a similar system on my 1913 which has a gauge

> reading 1 to 4 but 1 to 4 what I do not know. I merely have messed

> with the spring until it reads 2 running and all is well. The gear

> pump provided so much oil that a good two pints per hour fell out of

> the rear main bearing, making it a very tiresome and expensive Gordon

> Bennet Centenery rally in Ireland last week.

>

> On another note I found a 1919 engine and gearbox over there running

> a saw bench and hope to complete purchase of the same later this

> month.

>

The gauge is calibrated in pounds/sq", so that is what you are getting 2

lbs. In actual fact there is no relation to the reading on the gauge

and the actual amount of oil being delivered, as the gauge is simply an

indicator that the oil pump is working. Fitting a weaker/stronger spring

under the cap of the oil pump alters the reading on the gauge, but has

no effect on the oil delivery. In fact, the oil pressure stays up for

some considerable time after the engine stops, as it takes time for the

pressure in the pipe tobelled away past the valve in the top of the

pump. I think the gauges were pretty standard right up to 1926, being a

round one with black face and white needle, and wwere the same in

Hudson and Essex. The pump piston is forcibly driven by the cam, and

returned by the internal spring. You must adjust the eccentric

correctly to get increasing stroke of the piston as the speed of the car

increases. Or altenatively, you can lock it in the maximum position

and leave it there, after all that is what they did in '27-'29 models.

Good luck with the spare motor, it's amazing that these things are still

lying around the countryside. Here in N.Z. Hudson engines were used

extensively as winch and trolley motors in sawmills, and I always keep

my eyes peeld around derelict bush sites. have found a few remnants of

corroded alloy crankcases, but never a complete running engine, as the

mills were of cours located in high rainfall areas. have fun!

Geoff.