Oil pump pressure

[KWTownsend]

I need to put an oil pressure gauge on my speedster. Using a Datsun B-210 oil pump, what oil pressure would I expect? What gauge range should I use?

: ^ )

Keith

[Kevin Pharis]

The Datsun pumps on are capable of really high pressure. You have the Chinese aluminum pump, which has a bit more clearance than the iron Melling pump, and so outputs lower pressures. Don’t be surprised if you are making +50psi. I have cut down the bypass springs to get my idling pressure down to about 40psi. Runs about 75psi at 2500 rpm. I know it’s high, but doesn’t seem to hurt anything…

[KWTownsend]

Shall I use this old timey gauge?

[Kevin Pharis]

Looks good to me! Just keep in mind that the gage port on the oil pump is 1/8”-28bsp (British Standard Pipe), not 1/8”-27npt

[Dan McEachern]

Keith- just remember that pump is running at 1/3 over crank speed, so it can develop a lot of flow and the pressure that goes along with it. Those pumps run at cam speed in the original engine. The extra speed is not a problem, just be aware, and follow Kevin's advice.

[Dan McEachern]

OOPS!! duplicate posting.

[ModelTWoods]

I have a Datsun B-210 pump and adapter that I have never used. If I ever did, what would be wrong with using a pressure regulator on the output side. I bought one of those, too.

[Kevin Pharis]

The Datsun pump already has a built in bypass valve, but it’s generally better to consume the oil volume to reduce pressure, rather than waste it in a bypass circuit. The cast iron Melling pump I used to run would idle about 60psi and 100 at speed. I cut the spring down so that it would idle around 40psi. I switched over to the Chinese pump when I built my oil pump/alternator, didn’t have to cut the return spring as the pump naturally produced less pressure

[frontyboy]

On my Gallivan with its original oil pump, on cold start at idle it goes to 60 pounds when warm at idle 40 pounds. After a long drive it will idle at 30 pounds. I don't seem to have any obvious oil leaks due to the higher oil pressure.

This engine is fully pressure lubricated, drilled Wills St Clair counter balanced crank, tubular rods with pressure to the pins, and direct pressure feed to the mains and cam towers plus the timing gear case. As I mentioned on here earlier, I found a passthrough cleanable oil filter which made no difference in the various oil pressures.

just sayin'
frontyboy

[Henry K. Lee]

Oil pressure is a calculation of suction vs pressure vs heat besides the type of pump. If your pressure is high then your flow out from the pressure side might have to small of feed lines, fittings are restricted by means of manufacturing and quality of material, an improper relieve cut at the bearings (you must have a higher flow out at the bearings as this restrictions will kill your engine by means of heat and lack of oil being delivered to the cam lobes), etc. The built in relieve valve should not be modified for many reasons, here are a few...., bypassing like restriction causes heat due to cavitation (air bubbles) not our friend. Cooled oil by means of high flow rate, oil cooler (I use a power steering cooler on the pressure side) and increase the feed side of the lines as this cooled oil (more density) becomes much more efficient in lubrication. The aluminum body oil pumps normally lower oil pressure as they are dissimilar metals in expansion rates. The key in lubricating an engine is "Flushing" while supplying lubrication, so pressure is secondary. I run 10-15 pounds pressure at idle and about 40 pounds at 5,000 rpm. Yes, 5,000 rpm! Never an issue as my oil temperature on even a super hot day never goes over 145 degrees. A higher flow is your friend!

Ed Smith, A real old school engine builder has some excellent videos on Youtube explaining flow vs pressure, I refer a lot of my students here as the book has already been written!

[Les Schubert]

This posting is very timely for me as I have one of the aluminum ones installed on my T engine with the Borg Warner automatic installed. Thanks for sharing your experience and information!

[frontyboy]

I might add that the Gallivan engine was built in 1957 and been running ever since. When I dropped the pan for a cursory inspection, all bearing clearances were spot on. The oil pump is an original Gallivan part, also in the assembly of the engine a Gallivan oil pressure regulator was installed at the same time. With the modified deep sump, I run 2-1/2 gallons of multi weight Shell aviation oil. With that amount of oil I am not worried about oil temps.

just sayin'
frontyboy

[big2bird]

Excessive oil pressure/ volume would cost horsepower.

[frontyboy]

I guess that I'm not concerned at HP loss. The Gallivan has been radar checked by the state patrol at 113 mph at the Yakima Regional Airport. No I was not driving. The original builder was the driver. This was in 1959 when airport access was nowhere near what it is today. I seriously doubt I will exceed 60 miles per hour, I'm old and the reflexes are damn slow.

just sayin'
fronty boy

[babychadwick]

A nice thought is to drill out a bolt in the front plate and direct the bypass/relief there so that it doubles to put oil on the timing/dis/mag gears as well as the front of the motor.

[Dan McEachern]

These pumps use an internal relief valve that returns the bypass oil to the inlet of the pump- there is no separate bypass line.

[babychadwick]

No reason you can't put in a lower pressure relief and direct forward if the pressure is higher than desired.

[KWTownsend]

Update pics...

[KWTownsend]

I put in 5 quarts of oil. Is there any procedure for priming a B-210 oil pump?

Should I crank it over by hand and bleed the line until i get some oil to the gauge?

[Kevin Pharis]

I suggest pulling the coil wire and cranking it for a short bit with the gauge port open. Be sure to pre-fill your oil filter to ensure quick response. If no oil, possibly use a hand held vacuum pump do draw oil in from the gauge port

[Henry K. Lee]

I recommend filling oil filter completely, disconnect oil lines , outputs on pump, and fill with an oil can and turn engine by starter. Works everytime.