RB26 dry sump help

[trickymex]

Hi,

first i need to explain why im thinking of this as an option,

Reason 1.

The standard oil pump is the week point of the engine and upgraded ones are only a little better and extremely expensive, we are talking £600-£700

Reason 2.

The oil pump is driven off of the nose of the crank like most modern engines but they seem to cause alot of damage to the crank and as such damage the pump as well


This is my idea and please if i am missing somthing very obvious then please let me know.

The idea was to run a dry sump pump as normal but without a modified sump, that way i can use the sump as the tank and remove the internals of the standard pump as they are not needed, then take the pick up from the back of the sump.

I would like to relocate the oil filter anyway, then i can just remove the part of the pump that feeds into the engine and then just run the pressure feed into the original supply hole.

I know that i will not gain in the respect of scavenging while cornering or hard accelleration but that has never been a problem and its only a road car.

Just looking into it at the moment but all of your opinions would be very much appreciated

Regards

Ricky

[Guy Croft]

It's not unknown to use the single pressure stage of a d/s pump belt driven to do that, however there are some technical points I want to make.

1. You first have to find a pump. There as many oil pumps on the market as the day is long and I have looked at most of them. Most are not sealed/suitable for external (dry) mounting. You will find that belt driven d/s pumps are nearly all 3 stage. Only Brennan in NZ makes a single scav one. If you strip out the scavenge stage from such any such pump you will find that you've got no support for the shaft unless you mfr up a suitable end plate/blank .
2. One of the most important aspects of pump layout is the pickup. You'd have to fathom how to get a reliable suction feed to the single stage pump without inducing cavitation in the suction feed. Dry sump pressure stages are prone to this and the d/s tank should always be located above the pressure stage so it's not 'sucking' but being fed by gravity.

A lot of work and a vulnerable belt drive too, for what? I do question the negative aspects you mention about the nose driven oil pump. Internal external crescent gear oil pumps are a super design with a very high meshing frequency and I have never heard of a crank being damaged by one. Their widespread introduction solved many pump wear and failure problems and also gave far high delivery - esp on cold start, thereby reducing HC emissions.

GC

[trickymex]

Guy, thanks for the reply,

Here is some pictures to explain what i mean

I have and R32 GTR with the early pump drive, the later cars had a modified crank

This is the early type


you can see that the pump is only working on a very small surface area, after a while they tend to crack the drive gear in the pump.

This is the newer type



as you can see there is a lot more surface area and this solves alot of the problem.

[trickymex]

Do you think i could plump into the front of the pump and use the original pick up and return?????

here is a picture to show what i mean



i have marked the pick up and return, i was just thinking of tapping and fitting some aeroquip fittings on the outside of the pump.

What do you all think???

Is there any good reason why this will not work??

Regards

Ricky

[Guy Croft]

Sure, you could plumb in there; in effect the pump just becomes a housing and will probably work provided you blank off the current ports to the gears in the OE unit and the external pump is 'man-enough' - though I could not actually recommend one, sorry. I suppose the thing to do is try and mount the new external pump at the same kind of level as the existing one, you need to avoid a long suction pipe. No idea what you do for a pressure relief valve though; I guess the existing one will be 'back to front' and in the wrong place for your new feed.


GC

[trickymex]

Oh yes, Forgot all about the pressure relief, dont some dry sump pumps have an external pressure relief valve now???

Luckily i have mangaed to find out what flow the upgraded pumps runs, 57L at 6000 rpm, I will have a look and see what i can find pump wise.

I may end up going the conventional way just for peice if mind as its my own car that i use for cummuting

Thanks

Ricky