Oil pan 2.0 or 2.5?

[jamal]

For a good budget setup: 2.5 pan, Killer B pickup.
For a better, more expensive setup: Killer B pan and pickup.

There's not really any reason to consider anything else.

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[SurfWagon]

Thread necropsy. and hijacking.

I'm building a ej22t with s20 heads for a little tube frame car. I have room to design whatever I like, so I was going to modify an OEM oil pan, sort of like the cosworth pan. So is there any difference between starting with the 2.5 or 2.0 pan?

Height for the engine is a big concern, so I want to make the oil pan just about even with the tranny.

[mod maniac]

I'm not sure what you are doing but the 2.0 pan is more square. Nobody mentioned the dipstick is differant also

[KillerBMotorsport]

Originally Posted by SurfWagon

Thread necropsy. and hijacking.

I'm building a ej22t with s20 heads for a little tube frame car. I have room to design whatever I like, so I was going to modify an OEM oil pan, sort of like the cosworth pan. So is there any difference between starting with the 2.5 or 2.0 pan?

Height for the engine is a big concern, so I want to make the oil pan just about even with the tranny.

Kind of a catch 22. The EJ20 pan is shallow, but terrible baffling. The EJ25 pan is taller, but definitely has better baffling for performance type driving.

CHECK OUT THIS LINK FOR A COMPARISON.

What is the application? If I have some more background info on the car/setup/application I can give you a direction to head in.

[FuJi K]

The WRX 2L oil pan has been the one from back in the day. It's even on the EJ25D. The reason for the change on the STi oil pan is to clear the twinscroll header, which we don't have. Even the NA Subarus have the same pan now because of the design of the na header. Subaru can discontinue the 2L oil pan because it no longer needs to make them when all the newer cars run a header that wraps around under the engine, excluding the front facing turbo models. I wouldn't be surprised if the dealer required you to purchase a package of the newer pan, pickup, and windage tray with dip stick when going to buy a 2L oil pan.

The 2L has good control of oil sloshing around. Fill up the pans with a gallon of water and see how the baffle is placed. It's very open on the STi pan. I don't see issues with oil not being able to get into the pan. The 2L baffle tray is cupped up, but is NOT flush with the pan all around. The heads have little to no issues with oil flowing back through the block into the pan area. In turns of high lateral g-force it doesn't matter how good a pan you have, you'll have to be on the straight for oil to drain back towards the pan area.

Both pans are tilted slightly back how it would be on the engine.

[bako]

I ahve 02 wrx with original pan on it and I have problems on the track. oil is being collected in right cylinder head and then goes out from breather tubes (I'm lucky I vented all to atmosphere and did not let this oil go in intake tract again), even when I ahve 4.5 liter in the pan (I do say nothing about 5 liter of oil in the pan).

so I see 2.5 oil pan with 2.5 oil pickup can help in that. does any 2.5 oil pan suit my needs? even 2.5 NA engine pan/pickup?

I have stock headers also

[FuJi K]

Neither pan will help you in that situation. When you turn oil from the pan will go up and onto the head. That's the issue.

[KillerBMotorsport]

Fuji K hit it on the nose. This is why the rest of the world called the sump a 'twin scroll' sump and we here in the states call it an 'STi' sump.

Sloshing is not so as much of an issue as the boxer engine design If you're at that level of performance you should be running an aftermarket setup anyway. Where there is a difference in the two OEM pans, is the baffling.

The older 'flat bottom' style pans do not flow oil down into the bottom of the pan nearly as well as the newer style. Oil will go every which way before making its way down and the large bottom gives the oil a lot more room to move around in, even with the baffle. The newer style has a much better flow through baffle design for letting oil make its way down quickly. On top of that the bottom is shaped like a tub to make sure oil in the bottom is always pooled around the pickup.

When Subaru changed to the 'twin scroll'/'STi' design they changed more than just clearance for factory EL manifold. Baffling and tub shaped bottom improved oiling performance. It's not uncommon to see starvation (on track) with the older pan design, but while still possible, more difficult with the newer design.

Along with the pan design, the pickup and baffle were updated as well. The pickup is less likely to funnel and the baffle is a sligtly better with oil control as well. All these aspects are why we recommend a (older EJ20) car that sees occasional track use to to consider switching to the newer 'STi' design, for improved oiling performance. Beyond occasional track use, a performance high capacity pan will provide and an even higher level of oil safety and performance.

[KillerBMotorsport]

Originally Posted by bako

I ahve 02 wrx with original pan on it and I have problems on the track. oil is being collected in right cylinder head and then goes out from breather tubes (I'm lucky I vented all to atmosphere and did not let this oil go in intake tract again), even when I ahve 4.5 liter in the pan (I do say nothing about 5 liter of oil in the pan).

so I see 2.5 oil pan with 2.5 oil pickup can help in that. does any 2.5 oil pan suit my needs? even 2.5 NA engine pan/pickup?

I have stock headers also

You have a PCV issue by the sounds of it. As stated, no pan will solve this. There are some good threads going on IWSTI right now. Go take a peek

Originally Posted by FuJi K

When you turn oil from the pan will go up and onto the head. That's the issue.

Not nearly as much as most assume. It takes much less lateral force to fill the head vs slosh out of one. A long enough corner will fill the outer head and empty the pan without sloshing out any oil. This is really easy to see for anyone that has an engine/stand. Tip it and you can easily see how much force makes oil pool where and first.

One of these days I'm going to get off my butt and do a full on technical Suby oiling system write-up

[SurfWagon]

So i'm building a 1500lb car that will be 50/50 track and street. Probably starting off mostly as an autocross car, but built for track days. does that help?

[KillerBMotorsport]

Originally Posted by SurfWagon

So i'm building a 1500lb car that will be 50/50 track and street. Probably starting off mostly as an autocross car, but built for track days. does that help?

Rear mounted engine?

We've done a few pans/parts for the 914 Porsche guys.

[99imprezd]

Is the 2.5na(EJ253) pan the same as an STi(EJ257) Pan? Ive got a spare from a parted motor with baffle & pickup..?

[bako]

Originally Posted by 99imprezd

Is the 2.5na(EJ253) pan the same as an STi(EJ257) Pan? Ive got a spare from a parted motor with baffle & pickup..?

.................


+1?

[biodude]

i don't know if any info on the n/a pan in in here, but there is a good pic inside to compare too


http://forums.nasioc.com/forums/show...php?p=27383408

[99imprezd]

Ill have to shoot a couple pics and compare to the sti one after work.. The difference between turbo & non-turbo pans is ? The pickup looks exactly the same.. Ill put a couple pics up to compare later..

[SurfWagon]

It's a mid-engine setup with the 5MT converted to fwd, so that it runs the back wheels directly.

[KillerBMotorsport]

Originally Posted by 99imprezd

Ill have to shoot a couple pics and compare to the sti one after work.. The difference between turbo & non-turbo pans is ? The pickup looks exactly the same.. Ill put a couple pics up to compare later..

Here ya go

Originally Posted by KillerBMotorsport

OK guys I could go on for pages and pages on why the STi pans are better, but I'll try to keep the rambling to a minimum.

Here are the 3 pans. OK, 4 pans, had to give myself a shameless plug

Obviously the WRX pan is flat bottomed and not as deep, vs the STi pans that form a closer fitting 'tub around the pickup. This gives the oil less pleces to slosh around to, and keeps the oil level higher on the pickup during operation.

Top Left: Killer B Motorsport Oil Pan

Top Right: OEM 2002-2005 EJ20 WRX Oil Pan Subaru number 11109AA053

Bottom Right: OEM 06+ EJ25 Impreza WRX/STi (STi, Legacy GT & Forester XT) Subaru number 11109AA151

Bottom Left: OEM 04-05 EJ25 Impreza STi (Legacy GT & Forester XT) Subaru number 11109AA131





As most of us know, the STi pan can be used mith many more header setups do to the kicked-in feature.





The dipstick location and angle, shape, length etc. is the same on all pans. This is the little tube ON the pan. The only difference is the length of the tube that the dipstick sits in. It's different on the EJ20 vs EJ25. That's why if you just change the dipstick when swapping to an STi pan your readings are off. I'm not entirely certain if the brackets on the dipstick tubes are the same (I'd think they would be), but swapping dipstick AND pan should give proper readings.





On to the baffling... You can see the WRX baffles have fewer passages and 2 levels of baffles. The STi pan has a much more clear flow path. Keep in mind one of the achilies to the Suby lubrication system isn't oil control IN the pan, it's GETTIN the oil to the pan quickly as it flows back from the heads. It doesn't do you much good to have good oil control in the bottom of the pan if the oil isn't getting there.

A lot of the perimiter of the WRX top baffle is sealed to the sides. On the STi pan almost the whole perimiter of the top baffle has a flow through gap. Also tough to see in this picture is that the lip around the baffles (upper and lower) pickup hole is curled up. This forces the oil to one of the hols in the baffle instead of going right down the middle.





Here's another shot of the EJ20 double level baffle. It's tough to tell by this picture but it's mostly sealed around the edges. The flow through path takes many direction. I'd be willing to bet, because most of the sides are sealed on the lower level, that under hard accel, decel, & corners that you can pool oil in some locations between the 2 baffles.





In case anyone cares, the weights go something like this: EJ20-heaviest, 04-05 EJ25 next, 06+ EJ25 a little lighter and the killer B Oil pan a little lighter than the 06+. This picture shows the 04-05 & 06+ EJ25 pans. IMO the 06+ is a better choice, because it leaves half as much oil in the pan when you do an oil change, it's lighter, and the baffling is slightly better (although I'm probably splitting hairs here). Just an FYI on the 04-05 pan there is 1/4 quart that doesn't come out during an oil change and a baffle around the inside of the drain plug so you can't pump it out.



Something else to note is that the baffle tray (sheetmetal piece that bolts to the bottom fo the block) should also be changed when doing an oil pan swap. They are cheap, and specifically designed to work with each pan.



Hope this helps

Originally Posted by SurfWagon

It's a mid-engine setup with the 5MT converted to fwd, so that it runs the back wheels directly.

Very nice. Sounds similar to what the buggy guys do. There is also a VW micro-bus conversion too.

[KillerBMotorsport]

If anyone needs more pics from different angles or whatever let me know. We've got them all here

[SurfWagon]

I don't have a crosmember to content with, so I can extend the pan rearward. However, I do plan on a front mounted turbo, a la 2010 LGT.

[KillerBMotorsport]

Keep in mind how you stretch the pan and the pickup. The STi pan forms a perfect tub keeping oil right at the pickup always. It's got minimal space to slosh around.

By front mount, do you mean rear mount?

[99imprezd]

SO.. Heres a couple pics of a Non-Turbo EJ253 2.5NA Oil Pan which looks pretty much like the STi pan.. THis one came from a spun bearing motor so needs to be cleaned out but you get the idea..




actually it looks just like the '06 STi pan! Excellent.. now to clean this dirty piece out and get some fresh paint on her.. goin on my '06 100mm forged STi build! Stock baffle and covert pickup!

[KillerBMotorsport]

Originally Posted by 99imprezd

SO.. Heres a couple pics of a Non-Turbo EJ253 2.5NA Oil Pan which looks pretty much like the STi pan..

Exactly the same as the 2006-2013 WRX/STi (or an EJ25 after 2006) oil pan