Oil pump modifications.

[Suparata]

First of all there is no need for a higher volume or a higher pressure oil pump on a 4G6x since the stock flows “too much” at high RPM anyway so take care of the pressure relief valve instead.
Second the squirters do not open until you get to close to 40PSI anyway so what do you guys hope to achieve by eliminating one of the best thing the 6 bolt engines have? Sure as hell you won’t get any more pressure at idle and low RPM and trying to get “more pressure where is needed” at higher RPM argument does not stand since you should have close to 80PSI as soon as you go beyond 2500RPM even with the squirters in place. That is plenty where is needed.

Mitsubishi went through redesigning 3 times the “distribution” valve in the head and the one with the pressure relief valve was the first they dropped. Reason? There is only so much oil that can flow through a certain size hole. Which brings me to the next problem I have with what people try to do to “improve” oil pressure. You guys go through all sorts of troubles to improve oil delivery to the engine and then choke the system with external lines that are smaller than should be. While -8AN might be good for fuel delivery or transmission cooler, anything smaller than -10AN in the oil system is a restriction.

It is nice to have as high as possible oil pressure at idle but too much at higher engine loads is not so good for several reasons. Besides the load that the pump itself is subject to, the higher the pressure the hotter the oil will be making one of the most important things the oil does in an engine not as effective as it should be: cooling.

Bottom line, eliminating squirters and other “clever” things like that done to “raise” oil pressure is more than a waste of time: it is also a bad decision. Make sure you have the right clearances in the engine, use a good external oil cooler with adequate sized lines, modify the pressure relief valve and sit back and watch your engine being a very happy engine.

 

[Maglin]

I was looking at the oil galleys on the block. Why is their a restriction casted into the galleys?? the humps in both of them.. I can see removing them to increase oil flow but what are they their for... I've gone back and forth about the oil squiter removal... i'm using Forged Wesico pistons and don't have to have them... But at high boost levels you are really going to heat those pistons up... I'm probably just going to buy some new squirters and not worry about my pistons overheating and getting scored cause of it...

 

[Street Surgeon]

Oi, I'm not a mechanical engineer, nor am I a fantastic mechanic with years of experience under my belt, but removing the oil quirters under the pistons just sounds like a bad move. Can you get away without running them? Sure why not, but they're in place for a reason, and I'm positive that mechanical engineers collaborated with mechanics and they decided they should be there, and that's enough for me

On a side note... I bought a -10an oil return line for my 50trim, but the feed line (slowboyracing.com ss feed line) is deathly skinny should that be okay? I also bought an earls turbo oil filter / restrictor to keep superhigh oil pressure from blowin' that money up.

 

[espinelli]

On a side note... I bought a -10an oil return line for my 50trim, but the feed line (slowboyracing.com ss feed line) is deathly skinny should that be okay? I also bought an earls turbo oil filter / restrictor to keep superhigh oil pressure from blowin' that money up.

1/2" or -10an oil return line is perfect for your return. The feed line should either be a -3AN or -4AN. Make sure you get yourself a oil restrictor if using a -4AN line. As for the Earls PRE filter, don't bother installing it. You'll be lucky if that thing will filter objects no smaller than the size of rocks. I believe that is a prefilter product. Basically something used before the oil goes through the oil filter.

If you want to re filter the oil @ the turbo, check out Mr Gasket or Golan (same product) and they have -4AN filters.

 

[Street Surgeon]

What's good for RACE ONLY vehicles that are used once an event, often times isn't so good for a streetcar that's daily driven.

This is the filter I picked up, I just wanted some extra insurance.

 

[tmizer]

I've got that Earl's *filter* too, and news flash - it's just a screen for filtering out large debris. Open it up, and unless it's the sintered bronze element, it's just the screen.

AN hose sizing is:

AN number divided by 16 = inside diameter in inches (approximately).

...so a -8 is equivalent to a 1/2" hose, plenty big enough for domestics with large clearance engines, so even better for our tight clearance imports. The -10 cartridge return is just due to the AN fittings in my case and probably everyone elses. I hate it actually, as the larger hose is harder to bend....and since most of us are continually f*cking with our motors, smaller would've been better.

...and yes, the squirter issue has been beaten to death.

 

[espinelli]

..so a -8 is equivalent to a 1/2" hose

-8AN is closest to a 3/8NPT
-10AN is closest to 1/2NPT

AN number divided by 16 = inside diameter in inches (approximately).

This info probably applies to the outside diameter of the fitting.

 

[gsx951]

-8AN is closest to a 3/8NPT
-10AN is closest to 1/2NPT



This info probably applies to the outside diameter of the fitting.

I just measured an -8AN fitting and the i.d. was .372". We're safe calling it 3/8".
I went from the oil to water sandwich to a Setrab and have no experience with the O.E. '90 set up. What was the hose i.d. that the factory chose?

 

[Street Surgeon]

I've got that Earl's *filter* too, and news flash - it's just a screen for filtering out large debris.

Thanks for the newsflash... I bought it because I will be breaking in a totally new motor with a brand new turbo and I don't want any debris from the machining process getting caught up in the turbo. So I guess it'll be doing it's job.

 

[Maglin]

I think it's a better idea to break in the new motor with your old turbo that you don't care to use anymore... Even with a filter I personally wouldn't want to loose my new turbo from engine break-in.. That oil filter might or might not work... It's a PITA to swap a turbo just cause you are breaking a motor in but it's cheap insurance... Cost is next to nothing cept maybe a gasket and some time... And maybe one old turbo with now bad bearings, that's if they even get hurt... I know FP says not to under any circumstances to use a new turbo for engine break-in... It's just not worth it...

 

[espinelli]

Thanks for the newsflash... I bought it because I will be breaking in a totally new motor with a brand new turbo and I don't want any debris from the machining process getting caught up in the turbo. So I guess it'll be doing it's job.

The Earl's filter will not filter out the small debris that will hurt your new turbo. Maglin is right. I wouldn't break in a new motor with using a new turbo. Just use your old one during the break in process.

 

[Rick539]

Suparata mentioned modifying the oil relief valve. Did a search and found nothing. What is the mod to the valve?

 

[crankbender]

also when your adding a aftermarket oil cooler and feeding your turbo off of the filter housing this will effect oil pressure. your adding more area the oil has to go through and unless im wrong adding more space to an area wiht a certain pressure will drop said pressure because itll have to flow more to fill the said space.

this is my reason as i will have my turbo fed from the oil filter housing and running a aftermarket oil cooler. im not trying to bump it up to gain insane psi i want it as close to stock after i add these few things and i also want no where any contaminants to sit if for any reason they get into my oil.

Unless I am misunderstanding you then you are wrong. The oil-cooler should go in line with the engine and if well designed will not add a significant restriction. If you use too small of line however it will. The oil to the turbo should be controlled and the flow that it needs is based on design. In any case however you will never need a ton of oil and that little extra that is going there should not effect anything. If you are using a mitsu or any other water cooled/ball bearing turbo you should not run it straight off the oil filter. The turbo is not designed for the pressure and you can blow the seals out...mitsu had them on the head for a reason.

Oil is an incompressible fluid. I can take a sealed pipe of oil that is 200 feet long and if I suddenly expose one end to pressure the pressure will reach the other end of the pipe at approximately the speed of sound. In other words using a larger line that is always filled with oil (like a cooler etc) will in no way reduce the time it takes the oil to build pressure or, if properly designed for flow, the pressure seen at the other end of th eline. In fact going to larger lines and coolers can increase the pressure at the engine as the oil is slowed down and the viscous losses are decreased.

I think it is misunderstood that you always want more oil. This simply isn't true. Parts of the engine or turbo are designed for a specific pressure and flow. Exceeding either of these can caus ethe parts to run incorrectly and wear. Keep your pressure where it should be and don't blindly try to just get more oil.

 

[Suparata]

Suparata mentioned modifying the oil relief valve. Did a search and found nothing. What is the mod to the valve?

The stock oil pump delivers TOO MUCH oil at high RPM and therefore you get the so called “oil pressure creep”, meaning the pressure relief valve is overrun not being able to release all that extra volume from the system. And by the way it does that even with the squirters in place. But back to the subject, the pressure reaches too high which means nothing but troubles: too high loads on the oil pump, dangerous pressures at the oil filter and in the external lines/oil cooler, too high oil pressures within the engine including the head and, even if engine components survive the extra pressure, all that high pressure heats up the oil to the point when it doesn’t do one of the most important things it should which is COOL. So eventually “somebody has to give”.

Therefore the bypass system needs to be modified to be able to keep up with that extra flow.

 

[blue1]

Has anyone got a picture of the mod they do too the pressure relief. Do they just make the bypass hole bigger or do they make the hole oval so it relieves at the same pressure but is able to dump more flow!

 

[GRNDSM]

A couple of other problems with high oil pressure:

- blowing oil past the turbo seals (when turbo is fed from the oil housing)
- increasing the possibility of lifter “pump-up”

Unfortunately, I never took my own photos, so I am going to reference Brian Wilson’s photo:

http://www.utdsm.org/gallery/view_photo.php?set_albumName=album12&id=beforeafter

Personally, I think that this port job went a bit farther than I would be comfortable with (the last thing you want is for that valve to get stuck open…). But this should give you an idea what needs to be done.

 

[Suparata]

That is excessive in my opinion and can cause problems. Beside the possibility of having the valve stuck open, it also reduces the maximum pressure achieved and, if the actual passage that leads to that valve is also left alone, the goal of having the correct oil pressure in the system at all times is not achieved.
Mitch.

 

[GRNDSM]

That is excessive in my opinion and can cause problems. Beside the possibility of having the valve stuck open, it also reduces the maximum pressure achieved and, if the actual passage that leads to that valve is also left alone, the goal of having the correct oil pressure in the system at all times is not achieved.
Mitch.

Mitch,

As I saidl before, I also think that this is excessive. I did much less porting and I used my dremmel tool, which was much slower at removing the material.

I do not recall the passage leading to this valve as being restrictive, so I am not sure how much you are going to gain by porting it.

I suspect that this valve doesn’t actually open very far, so porting that outlet should help. However, quantifying the amount of required porting and its results will not be easy. Which is probably why there is so little information on this topic.

Leon

 

[sunflashx]

Mitch,

As I saidl before, I also think that this is excessive. I did much less porting and I used my dremmel tool, which was much slower at removing the material.

Leon

My filter housing was ported more conservatively than Brian Wilsons. There's a picture of it in that same gallery.

http://www.utdsm.org/gallery/view_photo.php?set_albumName=album12&id=DSCF0093

 

[Street Surgeon]

I think it's a better idea to break in the new motor with your old turbo that you don't care to use anymore... Even with a filter I personally wouldn't want to loose my new turbo from engine break-in.. That oil filter might or might not work... It's a PITA to swap a turbo just cause you are breaking a motor in but it's cheap insurance... Cost is next to nothing cept maybe a gasket and some time... And maybe one old turbo with now bad bearings, that's if they even get hurt... I know FP says not to under any circumstances to use a new turbo for engine break-in... It's just not worth it...

Agh, the old 14b has 140,XXX on her, and is very VERY dead heh, I dunno if that's gonna be an option

 

[Suparata]

I just measured an -8AN fitting and the i.d. was .372". We're safe calling it 3/8".
I went from the oil to water sandwich to a Setrab and have no experience with the O.E. '90 set up. What was the hose i.d. that the factory chose?

The oil passages on a 4G63 are roughly .470” which is around 12mm.
A -10AN hose end fitting has an ID of .480” and a -10AN-1/2” adaptor used when a proper oil filter relocation kit is installed is .485” therefore -10AN IS the right size to use.

-8AN hose end fittings and -8AN-1/2” adaptors have an ID of .390” which is less than 10mm which is the first obvious restriction when -8AN is used in the system.
Now hold on to your pants because here comes the “best” part on a -8AN setup: the 16x1.5mm-10AN adapter goes down to an ID of roughly .320” which is a little over 8mm!!!!!!!! Now how is that for a nice restriction?

What I’m trying to say here is that, even though hoses look thick and “plenty big”, the overall flow “capability” of a particular setup will be dictated by the ID of the connecting fittings because a hose is as “big on the inside as the smallest part of it is”.

That’s why anything smaller than -10AN on our cars IS restrictive.
Mitch.

 

[NDgsx]

Anyone still thinking about this toga oil pump go back and read Mitch's post on the top of this page, that's 100% correct. If you see a thread about it again please refer them to that post.
Just too see if anyone is paying attention to anything other than cars, there are motors that don't even have oil pumps, first person to get it right gets a cookie.

 

[Maglin]

Anyone still thinking about this toga oil pump go back and read Mitch's post on the top of this page, that's 100% correct. If you see a thread about it again please refer them to that post.
Just too see if anyone is paying attention to anything other than cars, there are motors that don't even have oil pumps, first person to get it right gets a cookie.

You talking about almost all Briggs and Strations?? They don't use oil pumps. Insead they use a oil slinger which works ok and kepts cost down as well as not as many moving parts to break down.. Yes to much oil press is a bad thing... Had a old school hot rodder buddy do the spring stretch on a SBC back in the 60's.... He said he oil press at idle was almost 100 PSI and off idle it pegged the gauge.. After a few months of it running that like it started knocking... Apon tear down all the bearing were washed out... It was so much pressure it actually washed away all the bearing material... It was all almost solid copper... You can learn things from Old Timers every now and then...

 

[NDgsx]

You talking about almost all Briggs and Strations?? They don't use oil pumps. Insead they use a oil slinger which works ok and kepts cost down as well as not as many moving parts to break down..

Yup that's what I was thinking of
So is chocolate chip ok?

 

[Maglin]

Yup that's what I was thinking of
So is chocolate chip ok?

Choc. Chip is fine..