Hi Press. Oil pump

[Socalman]

I am having low pressure at Idle, I haven't driven since I am waiting on a driveshaft. but idle is about 15- 20psi, I had read somewhere an oil pump from a different model can be used and is higher pressure....I tried to search but had no luck..

[russaroll]

you can take the plug off the oil pump and put a small washer in there under the spring.  that should increase your pressure a bit. 

[Crashtd420]

Hitachi OUP0023 Engine Oil Pump https://a.co/d/07bUafOJ

[banzai510(hainz)]

I recently did both my L motors last year with the above mention pump.

[Socalman]

Thank you!

[Stoffregen Motorsports]

Yeah it's not a high pressure pump, but high volume, which does increase the pressure.

 

Used to be the L28 turbo pump was the only one, but KA24E pumps are the same.

[mainer311]

15-20psi at idle is completely fine for an L-series. I’m running the OUP0023 pump mentioned above and my pressure at idle while hot is only 25psi.

[datzenmike]

Oil 'leaks' more and more past the rod and main bearings as they wear. The oil pump simply can't keep up and the pressure drops with age. Shimming would not improve idle and low speed because the volume is the same.

 

Get a KA24E or KA24DE oil pump from a D21 Hardbody. The internal rotors are 13% longer so they move more oil per turn. My tired L20B was 17 PSI at hot idle. With no other change than a used junk yard KA pump it jumped to 29 PSI. Maximum pressure remains the same at 50-55 PSI but it gets there sooner.

 

[mainer311]

8 hours ago, russaroll said:

you can take the plug off the oil pump and put a small washer in there under the spring.  that should increase your pressure a bit. 

Not at idle it won’t.

[Socalman]

Once I get the fans wired in I’ll let it idle a bit. This engine did sit for over a year even though everything looked good and clean inside when I dropped the oil pan and removed valve cover, maybe I’ll even do a compression test. 

[banzai510(hainz)]

Mine is at about 35 pounds at idle. with 15/40  20/50 oil.

 

just depends what idle is aI guess. so as I come off idle the pressure is 80

[datzenmike]

Pressure goes up immediately as you come off idle. Each turn shoves 13% more oil into the engine and that soon adds up. Maximum pressure is reached sooner and at a lot lower RPM.

 

You can't tell if it's a high volume pump if mounted on the engine, all the differences are internal. Essential if you have a turbo or spray bar.

[Socalman]

So this is where my concerns are or is it normal? The 1600 was much higher. 

[Socalman]

 That’s idling at around 600

[mrbigtanker]

Im going to say yes. Also what oil weight you running, my Robello runs low until you bring it on. No problems. 

[datzenmike]

 

 

600 is a little low for me, what does it read at 700???

 

I know you, and I would like more oil pressure, more is better right? but just how much HP is any engine making at idle??? That's right just enough to spin the engine at 600 or whatever RPMs. Can't be that much as you can spin the engine by hand. I looked up starter power and on average around 1 HP. So lets double that as starters don't spin engines at 600 RPMs

 

So if making 2 hp I think 12-15 PSI is plenty of lubrication. 3 1/2 hp lawn mowers rely on splash oiling at 3,500 RPMs. 

 

 

Put a KA oil pump on bet it goes up at least 10 PSI

[mainer311]

600rpm. Thing sounds like it’s struggling to idle. No wonder it’s low.

[datzenmike]

100 more RPMs is 100 more pumps of oil.

[banzai510(hainz)]

Your most likely fine if it was bad your motor would have went bad already

If your comfortable at swapping a pump I say 70$ is a good investment esp if you have a cam with stronger springs. with that Pump above

 

Mine would read low once warmed up really good. In mosrning it will be higher with the oil still thick.

 

I would maybe ajust the speed screw and get the speed up or both mixture and speed screw adjustment

 

[Socalman]

11 minutes ago, banzai510(hainz) said:

Your most likely fine if it was bad your motor would have went bad already

If your comfortable at swapping a pump I say 70$ is a good investment esp if you have a cam with stronger springs. with that Pump above

 

Mine would read low once warmed up really good. In mosrning it will be higher with the oil still thick.

 

I would maybe ajust the speed screw and get the speed up or both mixture and speed screw adjustment

 

 

18 hours ago, datzenmike said:

 

 

600 is a little low for me, what does it read at 700???

 

I know you, and I would like more oil pressure, more is better right? but just how much HP is any engine making at idle??? That's right just enough to spin the engine at 600 or whatever RPMs. Can't be that much as you can spin the engine by hand. I looked up starter power and on average around 1 HP. So lets double that as starters don't spin engines at 600 RPMs

 

So if making 2 hp I think 12-15 PSI is plenty of lubrication. 3 1/2 hp lawn mowers rely on splash oiling at 3,500 RPMs. 

 

 

Put a KA oil pump on bet it goes up at least 10 PSI

 

4 hours ago, mainer311 said:

600rpm. Thing sounds like it’s struggling to idle. No wonder it’s low.

I don't claim to know anything about Datsuns, but I love the 521, thus I come and ask questions. I took the advice and also went a step above, I set timing to 14* and idle to 800, everything seems normal, it even sounds preppier on throttle with the dual Dcoe 45s. This is a new install, I havent drove it since I am waiting on a one piece driveshaft...I dont however like the way the 5speed ended up, but that will be added to another post with pictures...Maybe I went the wrong direction somewhere....lol

[Socalman]

Thanks for the help...

[banzai510(hainz)]

yeah if you have duals I would do 14/15 deg anyways on initial adv.

My manual on SU carbs for L1666SSS was 14

Edited Wednesday at 09:33 PM by banzai510(hainz)

[mainer311]

15 is fine since there’s no vac advance.

[datzenmike]

There are 3 types of timing.

 

Initial... set with a timing gun... 12 degrees

Mechanical, AKA centrifugal... this timing increases with engine RPM and is designed into the distributor ... about 20 degrees

Vacuum advance.... load dependent, light throttle higher advance added, heavy throttle (WOT, wide open throttle) low intake vacuum basically no advance.

 

At full throttle and above 2,500 RPMs the L 4 engines seem to like to run best at 32 degrees total advance That's initial and mechanical added together. Forget vacuum advance you are at WOT.

 

If you increase the initial advance from 12 to 14 it's fine at low throttle and RPMs but at WOT 14 +20 = 34 degrees and you may encounter detonation which is not good. Just listen to your engine when floored above 2,500 and if you hear anything go back down to 12 degrees.

[Socalman]

True, I need to check total as well. It’s just really loud with open headers at the moment. lol…..