Suggestions for oil pump replacement 4AGZE/GE

[fetish]

Hi guys, a friend is shopping around for an aftermarket oil pump. whats available for these engines. recommendations, where to purchase etc.

cheers

[trdee]

20v oil pumps are supposed to be interchangeable and of a more robust design

[Billzilla]

Apart from an external pump like a Peterson unit, you're not going to get anything that will fit.
Also, unless you're doing something a bit odd you don't need one anyway.

[rick q]

What Bill Said............

The standard pump is fine, it's available over the counter from Toyota and the smallport one is the same as the 20V one.

[fetish]

thanks for the info guys, ill let him know.

[Dangerous Beans]

I'm rebuilding a 4agze, and have a couple more questions on this topic:
Is there anything that should be done to improve these pumps?
Should I reuse the old one if it's still good, or just get a new one from toyota?

[privatealpha]

The standard oil pump should be good up to 400hp at the wheels.
So unless you're making more than that, you should be fine.

[shrike]

If you shim the oil pump it will flow alot better

[_FNQ_rolla_]

If you shim the oil pump it will flow alot better

Just a question about the shim,

I've heard of people shimming their oil pumps but how thick is this shim and where exactly does it go.

(a picture would help)

thanks

[Dangerous Beans]

There is a not great picture here: http://s29.photobucket.com/albums/c2...t=pumpshim.gif
It is for a 7m pump.
As i understand it the pump has a pressure control section that uses a piston and spring to bypass oil around the pump. when you shim the pump the shim compresses the spring, making it stiffer and meaning that the pump has to pump more oil to to push it open.

As for how thickly to shim it: I would like to know too.

[stepan117]

or you can try this HKS mod kit http://www.nengun.com/hks/4a-g-parts

[oldcorollas]

There is a not great picture here: http://s29.photobucket.com/albums/c2...t=pumpshim.gif
It is for a 7m pump.
As i understand it the pump has a pressure control section that uses a piston and spring to bypass oil around the pump. when you shim the pump the shim compresses the spring, making it stiffer and meaning that the pump has to pump more oil to to push it open.

As for how thickly to shim it: I would like to know too.

this is not exactly true.
the pump is a positive dislpacement type. it will pump a more or less fixed volume of oil for a given speed.

since you don't want 11th billion psi oil int eh motor (too much power loss) the max pressure is capped by the pressure relief valve. this valve opens when the oil gets to a certain pressure and allows the extra pumped oil back into sump.

this is the valve that gets shimmed. it just means that the pump has to make higher pressure before the valve opens.

in practice, full pressure is not made until maybe 4000rpm? below that, the valve is fully closed. above that, it bleeds volume to keep the pressure at the set amount (set by the relief valve)
if you shim it, then it will open later BUT it may not be much later and not much more flow.

the volume of oil flowing thru engine is a function of the leakage rates from each opening. the pressure is a function of how much oil is not leaking from those openings.

having higher pressure will maybe float bearings a bit better, at the expense of power loss and extra heat created.


anyway, shim away, but don't expect a highr oil flow from it, just a higher pressure.
and don't bother with a higher volume flowing pump without increasing the pressure, or you will just start bleedign oil off to maintain that pressure, at a lower rpm..

[TERRA Operative]

Apparently you can 'port' the oil pump, round off all the sharp edges in the housing or something.

Might help a bit.

[DX20VT]

this is not exactly true.

Yup,

If you are having low oil pressure problems, no matter what size or shape shim you fit,
you will not get any more oil pressure.

The relief valves do not open until about 70-80 psi anyway,
and so why do you need more than that.

Most motors would struggle to make that pressure when the oil is at full temp anyway,
unless you are well past the std RPM limit.

[oldcorollas]

i think the 4A pumps open around 40-50psi when hot?? can't remember..

I did the shim thing to my K pump to bump up pressure as well. i think it does increase pressure when oil is cold, but doesn't mean you are getting any more to the actual bearings...

As Terra said, and Bill has said before, you can "port" the housings to remove sharp edges and reduce losses in the pump. be careful when doing this as you don't want to mess up the "timing" of the ports, or you will lose volume flow