Oil Pump -- PHR vs OEM

[Jellybean]

For BPU what is recommended PHR modified or OEM?

 

 

Based on the below, will PHR modified Pump just cloak the fact you have an issue with your pump wear? due to the larger Drain hole preventing the pressure from building up behind the FMS

 

Originally Posted by Tricky-Ricky

OK in simple terms,wen the oil pump wears, especially on the front spigot area, it allows oil past into the very small void behind the FMS, this area has a small oil drain hole, which as std is not up to the job, the consequence of this is oil builds up at higher RPM and due to pressure overwhelms the oil seal,

The seal will very often look fine, all you will find is that the spring that is in the oil seal is displaced, but believe me it is almost always due to the oil pump.

 

http://www.mkivsupra.net/vbb/showthread.php?t=190940&highlight=fms&page=3

[Stephen G]

i would have thought oem does the job 100% even on big bhp engines its the sump getting pressurized is the main problem thats why a breather system for the sump is needed

[Tricky-Ricky]

i would have thought oem does the job 100% even on big bhp engines its the sump getting pressurized is the main problem thats why a breather system for the sump is needed

 

Rubbish! its been proved that the problem is down to the oil pump wear, ask CW, i have had this argument with the US guys, who where also convinced that its all down to crankcase pressurisation,

 

So i will explain it to you the same way, there are two things that you have to remember piston ring design, (and this particularly applies to turbocharged engines,) is that the more pressure applied to the rings the better they should seal,

 

now the counter argument to this is that if things are not 100% in the cylinder there will be leakage, and therefore crankcase pressure will develop for which the seal problem is supposed,

but there are other factors to consider.

 

First is that the std PCV system is perfectly adequate, and will cope with all but the VERY worn ring and bore wear,

the second is that in order for excess crankcase pressure to cause the seal to fail the pressure transfer must take place via the std 3/16" oil drain hole, now in my experience of pneumatics in order to push enough pressure through the 3/16 drain hole it would require very considerable constant pressure within the crankcase to accomplish this, so the rest of the motor seals gaskets would be showing severe leakage.

 

Now the reverse side of this is that, with the oil pump leaking enough oil to fill the void between the pump case and the seal (the area is about 40cc) it takes very little wear to accomplish this and so as soon as there is enough wear the void pressurises and as hydraulic pressure is much more efficient (IE can generate more force for the pressure) than pneumatic pressure, the seal will readily leak and fail,

All the modified pump does is give more leeway for the pump to leak a little, before causing the the seal to fail.

 

I will also add that even with a pump that was leaking enough to cause my seal to fail even with a modded (enlarged) 1/4" drain hole,it was still making more pressure than the new OEM pump that i replaced it with, so it in no way effects the engine integrity, (disclaimer unless your pump is completely fooked)

 

 

Oh! i almost forgot, due to my problems with FMS failure, i ran some tests, in the form of an accurate low pressure gauge sealed to my dip stick tube, and at no time did i record any positive pressure, this was with hybrid turbos running 1.3 bar with the std PCV system but with a catch can in between.

Edited July 10, 2010 by Tricky-Ricky (see edit history)

[Stephen G]

that me told off:)

[Tricky-Ricky]

that me told off:)

 

[nigelboyne]

what sort of mileage or age before the pump gives way or is it life of car if you use high grade oil and filter and 5k changes, i am running a little rich is thus also bad for the pump. should carlos just replace the pump and he be ok or has it a kock on effect

[Tricky-Ricky]

Put it this way when my seal failed for the third time i replaced the pump, there are some pic knocking about somewhere,

 

But my engine had only done in the region of 40K completely std, and AFAIK it had been maintained well, so i am inclined to think that as with most turbo cars the fuelling is set on the over rich side,

so oil dilution may have played a part, although i do think that the pump cases being alloy may suffer from premature wear for whatever reasons,

Thinking about it could even be due to capitation effects at high oil pressures/RPM, or just picking up some debris from the oil pan, as there is only a very coarse screen filter before the pump.

 

I will also add that surprisingly there where no signs of wear in the big ends or mains, and i later singled my Supra and it has been running in excess of 500BHP for the last two years, and the new owner is running it at very high speeds on the German autobahns.

[nigelboyne]

rick was your car a uk car

[Tricky-Ricky]

rick was your car a uk car

 

No! J spec.

[nigelboyne]

very hard to verify the mileage but great write up very infomitive thanks mate

[Tricky-Ricky]

very hard to verify the mileage but great write up very infomitive thanks mate

 

Yeah! i know but mine was supplied by Jurgen, so no reason to doubt;)

[Jellybean]

Thanks for the detail Tricky

 

If I understand correctly , another seal failure (i.e piston ring) is causing the build up of pressure to overwhelm the FMS(Front Main seal) therefore if you dont identify the source causing the pressure it will happen again.

 

Just changing the pump or FMS is unnesscary as this is not the issue, they are working as per design, it is the source of the issue needs attention. once replaced, you should negate any further pressure on the FMS, therfore it can work within its threshold as it was designed

 

Thats my 2 cent

 

Nigle, got to check the car between rain showers; looks like it is the oil cooler -10 AN fitting; the leaked oil is between the AC rad and front bumper (oil cooler is located here); I ran my hand along the connections , some fresh oil on one of them so I will get some plumbers tape and tighten it back up; hopefully should do the trick. I will get her up on a ramp then make sure nothing else is causing a leak, heart attack over

Edited July 10, 2010 by Jellybean (see edit history)

[Tricky-Ricky]

Thanks for the detail Tricky

 

If I understand correctly , another seal failure (i.e piston ring) is causing the build up of pressure to overwhelm the FMS(Front Main seal) therefore if you dont identify the source causing the pressure it will happen again.

 

Just changing the pump or FMS is unnesscary as this is not the issue, they are working as per design, it is the source of the issue needs attention. once replaced, you should negate any further pressure on the FMS, therfore it can work within its threshold as it was designed

 

Thats my 2 cent

 

No! sorry either i haven't explained it correctly, or you haven't got the gist of it.

 

The ONLY definite cause of FMS failure is the oil pump wearing!

 

The only way that the FMS could fail due to crankcase pressure is if one or more cylinders was completely;y fooked, and this would be far more apparent by other indications other than seal failure.

 

Have another read;)

[Ian C]

Just having a think about this, another nail in the coffin of ring sealing causing the crankcase to pressurise is this - You'd expect all six cylinders to wear at roughly the same rate. Only one piston is pressurised at any one time with a combustion event, so the first thing the gas would do (if the PCV system wasn't handling it) would be to escape up the other 5 cylinders, past the equally-worn rings around those pistons, and out into the exhaust or intake where pressure is considerably lower.

 

Sound plausible?

[Jellybean]

No! sorry either i haven't explained it correctly, or you haven't got the gist of it.

 

The ONLY definite cause of FMS failure is the oil pump wearing!

 

The only way that the FMS could fail due to crankcase pressure is if one or more cylinders was completely;y fooked, and this would be far more apparent by other indications other than seal failure.

 

Have another read;)

 

Got you, my explanation was the US rubbish what they taught was happening; so in short FMS leakage = Worn pump which should not damage your engine unless you have a catestrophic failure of the oil pump

 

 

I think I will also do a compression test later this week to be safe

[Tricky-Ricky]

Just having a think about this, another nail in the coffin of ring sealing causing the crankcase to pressurise is this - You'd expect all six cylinders to wear at roughly the same rate. Only one piston is pressurised at any one time with a combustion event, so the first thing the gas would do (if the PCV system wasn't handling it) would be to escape up the other 5 cylinders, past the equally-worn rings around those pistons, and out into the exhaust or intake where pressure is considerably lower.

 

Sound plausible?

 

Yeah! i see where you're going, i would presume that the engine designers would of factored in quite heavy cylinder wear into the design of the PCV system, as these engines where designed to do big mileage anyway, the pressure equalisation and escape within the engine is pretty good due to the large transfer apertures, so the the large pressure required to transfer the amount required to cause the FMS to fail would as i said be quite considerable and wold show as (apart from the obvious big loss in power) would be gaskets and other oil seals leaking.

 

I do wonder at the difference the dynamics of the moving pistons would make to pressure escaping past the worn rings though?

[Chris Wilson]

It's worn oil pump internals and / or a wear groove on the nose of the crank where the seal abrades. There was a plethora of seal failures a few years back, around the time a now defunct tuning company was fitting budget single turbo kits. The engines were suffering oil dilution due to the mapping, (or maybe the lack of mapping), allowing the engines to run crazy rich. Fuel contaminated oil is very unkind to how the lubrication system functions. There were also issues with rebuilt engines being contaminated by very poor assembly cleanliness allowing abrasive particles to enter the pumps and wreak havoc.

[Guest captainb]

So in a nutshell:

Replace with OEM pump? problem will/may reoccur at some point once oil pump begins to wear.

To account for additional pressure when oil pump is wearing out.

Modify the OEM pump so problem wont occur as the drain hole is larger

Buy PHR pump so problem wont occur as the drain hole is larger

and If the nose of the crank is worn. Buy a new crank (These can't be cheap)

 

Could someone confirm I've got things right.

Edited July 22, 2010 by captainb (see edit history)

[Guest captainb]

Anyone ?

[Chris Wilson]

I would just put a stock Toyota pump on it, after checking there's no excessive wear ridge on the nose of the crank. These can be plasma sprayed and re ground, but given an N/A engine has the same crank it may be cheaper looking for a perfect used crank to replace yours with if it's goosed.

[Guest captainb]

Cool thanks Chris.

I was reading about how people use a tool to put the gasket in ?? sounds a bit strange.

Also any particular recommened brand to seal the sumps back up again ?

Are there any photos of a worn crank ? or is it quite obvious ?

[Guest captainb]

taken it apart and its only the oil presure relie valve thats leaking now. I already replaced this so I know the valve is good. I'm guessing it is down to a worn oil pump.

can I just replace the gear oil pump drive or do I have to buy a new housing too ?

 

Thanks

[Chris Wilson]

You can only buy, AFAIK, and SHOULD only buy the whole assembly. The case will be worn if the rotors are.