The 6 Quart Oil Pan Spacer - Gen 2
 

As I was going down the oil pan path, I got sidetracked designing this part. As simple as it is, aside from increasing total capacity to a US friendly 6 quarts even, it has the potential to moderately improve some other things...

The vertical wall at the front can potentially decrease slosh going into the timing cover under hard braking and right-hand turns. The vertical side-walls potentially decreasing the effects from slosh.

The 3X increase in distance from the bottom of the pan decreases the probability of sucking up some of the dreaded silicone.

The increased capacity has the obvious effect of decreasing oil temps some.

While the spacer does increase the distance to the bottom of the pan, the spacer is at the top (where the area is largest), it will also increase the oil level at the pickup when the engine is running too. In theory, this will contribute to improvements in oiling, as there will be more oil in the bottom section of the pan, where it is held closest to the pickup.

Has two ports: (1) NPT, (1) BSPT, for turbo drain back or oil temp sensor.

I hadn't initially considered going down this road, but it has the potential to add a moderate improvement in oiling performance for WAY less money than our oil pan. What price? Too early to say, but if the machining time isn't too bad to carve down a chunk of billet, we might be able to hit the $149 mark.

Thoughts, feedback, and comments welcomed.

https://killerbmotorsports.sharepoin...VXv-w?e=ga6Nqm

Cool idea :)

Where are the ports at in the spacer? If installing a temp sensor, would you expect it to have relatively stable readings?

Thanks!

If you look on the front side, you can just make out the two ports. As far as stability, I can't say. The ports should be submerged under most conditions.

I see the ports. Do you foresee any issues with stock exhaust manifold/headers with the ports there?

Anticipated clearance to the lower engine cover?

I'm excited to see this and totally in at projected price point.

What would you do to extend the pickup to make use of the extra oil depth? Doesn’t the timing cover need to come off to remove the pickup?

Couple of suggestions:

1) Add three more ports. One for an aftermarket oil temperature gauge and two to install an oil cooler heat exchanger hard line inside the spacer plate where one could connect an aftermarket oil cooler and pump with a small reservoir to circulate cooling fluid, such as water/antifreeze or even engine oil through the lines.

2) Design the spacer plate to take a gasket on the top side and a gasket on the bottom side with a heavy duty aluminum oil pan retaining ring that sandwiches the oil pan sealing surface between it and the spacer. Basically, eliminate the need for using high temp sealant altogether when it concerns these oil pan components. You'll have to design and supply the two gaskets, of course, but this would at least eliminate one of the many headaches and sources of potential RTV clogging while making it user serviceable for the future.

3) New product to sell: Oil Pan Gasket Kits

The oil level would not change, you would add extra oil to compensate for the increased volume that the spacer provides. Just monitor your oil level as you always would.

The reason nobody wants to use a gasket is because they are much more prone to leaking. Unless you can tighten every bolt down at the same time, it can be a pain.

So far, no, but we haven't engine mounted it yet. According to my scans, it should all fit with some clearance. It's obviously less, but the Suby engine/mount setup doesn't typically allow for much movement downward. The engine mostly tips from one side and moves forward.


You may have missed the details I laid out in the OP. The level around the pickup increases because the pickup is in a smaller area than the spacer. So even though the pickup is higher from the bottom, the oil level becomes even deeper than that height. A benefit of this, is less likelihood of sucking up broken off pieces of silicone.

There are two ports there already. There's physically not enough space to make ports for doing a proper oil cooler setup.


Been there, done that. They don't work for a number of reasons. The pans aren't that flat and too flimsy, the FA sealing surface is too small, the bolts are too far apart, etc., etc... We've done o-rings, rubber, and cork. I would recommend none, unless you are removing the pan a LOT. When I say a lot I mean after six rally stages, or after a few drag passes... stuff like that. We do use them, but ONLY for short term stuff, like oil product testing where the pan comes off every 6 dyno pulls and that would happen a dozen times over a week. We use them then as a time saver, but they do not hold up much beyond that.

Another benefit I didn't state in my OP, is that this spacer is very thick and is going to have machined surfaces. You can use FAR less sealant when installing the spacer, and also inspect to see how much has oozed into the inside. Additionally, you could use your finger and remove and excess that oozed inward if you wanted to. The spacer also has a wider sealing surface than the block, which should mean a better seal with potentially less sealant.

Correct!


Very true!

Even if you could tighten them all together (which is how the factory does it BTW), the design is just not well suited for it. Too little sealing surface on the block, too flimsy (and not very flat) of and oil pan, with bolts too far apart. It just doesn't work. It's one of those things that sounds good in theory, but in practice just does not work.

If i was in that situation i would just run drop the pan for a baffle and clean out the rtv. Seems like it is over complicating things. Baffle + pickup + sandwich plate for oil cooler works for me. KISS

Just curious: What is the buoyancy of silicone in oil? Does it float or sink? Does the buoyancy change with temperature? Am I over thinking the problem?

I could design the heavy duty aluminum retaining ring to work. It would seal all surfaces evenly when torqued in a standard star-type sequence.

And I could design the gasket to seal without using additional RTV.

The Ford 5.0 used steel bars between the bolts and the pan flange, torqued in sequence they applied pressure quite evenly. I feel like nickel and dime savings have sent many functional ideas to the scrap bin of history.

Similarly, it wasn’t uncommon for engines of just a couple decades ago to have cast-in grooves for extruded rubber seals & o-rings that only needed a dab of RTV at junctions. Of course simplifying castings won out favoring RTV everywhere, since it saved pennies.

With the fiasco of the first gen recall killing engines, I’m still confused why an anaerobic sealant wasn’t adapted in place of RTV. The entire clogged pickup and plugged oil passage issue would cease to exist.

No pickup available for the FA24, and nothing conclusive showing any currently available baffle improves anything. If you have datalogs showing otherwise, I'd love to see them!


There is no silicone in this part. If you're thinking of the flapper valves that some use in thier baffle, they sink like a rock in oil.

With a non-flat pan flange, that would be impressive!


I used to share that same outlook. You must be old too :lol:

Over the years technologies change and there's always growing pains. Subaru started using these sealants in the 90s and it has mostly gotten better. You see that trends now on the higher end products now too: Porsche, AMG, etc... With that trend has been a reduction in part numbers, labor hours for assembly, and believe it or not... leaks. While a clogged pickup is a HUGE problem, the $ saved is still there. If that changes, the design will too. Watching the industry trends and future investments in this technology it's only going to be used more and more over time. If it frustrates you in use, I recommend trying some higher end adhesive gaskets by Porsche and another made for the Audi RS series. The cost is a crapload more! They come off easier and one of them (I can't remember which) cures under compression and time, so anything squeezed out essentially dissolves in the oil.

I was thinking more of the sealant. When it breaks off, does it float around, or sink to the lowest point?

Good question... and here's your answer...

https://www.youtube.com/watch?v=4DYfs02Lk5E

Non-flat? It appears to be flat in all of the places that it needs to be.

Attachment 216674

Okay, here's what I'm going to do. It's been a while since I stepped in to solve a problem, (ask ole' @Tcoat what I did for him a while back) but this OEM oil pan sealing design using sealant instead of normal gasket material sucks! Especially if you do the labor yourself or if you rely on dealership stooges who don't give two shits about the quality of their work to do it for you.

I'm going to purchase a brand new oil pan from the local Toyota or Subaru dealer and I will get started on this project. If anyone would like to collaborate, know that I do this to solve problems for personal gain, and to help others in our community. I don't do this for profit. PM me if you care to offer assistance.

LOL just yesterday I was listening to a song on the radio and smiled at how good it sounded and how much I appreciated the help!

There is very little that is "flat" on the 86 oil pan. The pan has a ridge and the mating surface a groove that are designed to hold the sealant in place and create a seal. Although a gasket could certainly be made to fill that I would have a concern that due to the wide spacing and relative thinness of the pan material you would have a rough time getting enough even pressure on a gasket to prevent leaks.

https://external-preview.redd.it/gbi...=webp&af8185eb

https://i.imgur.com/YIY4XKQ.png

Of the dozens of new Subaru pans we've gone through over the years, exactly zero have been flat. I have a brand new BRZ one here that came out of the box a couple of weeks ago, and it's not flat too. What's worse is when customers remove the pan, it often get mangled and is definitely NOT flat. Some look like they've been hammered back into shape with a rock :lol: The sealant doesn't care.

I would recommend your first thing to try is bolting down a dry OEM lower pan to the top pan, measuring how much it flange lifts between the bolts. It starts to lift as you approach target torque spec (~8ft/lbs IIRC), and gets way worse if you exceed it. Again, the sealant doesn't care.

A back plate would help maintain flatness, but you'd be needing to use a higher torque spec (higher torque rated bolts) and those are only M6 threads in the block.

Maybe a thick back plate with a gasket? O-ring has nowhere near enough room (~.09) on an FA24 unless you use an inappropriately small one.

It's a good challenge for sure, I applaud your stubbornness. We've been down this path more than a few times and don't use sealant on some unique setups. If there's any data, dimensions, or otherwise, we can provide for your journey, please don't hesitate to ask.

The cost would probably be way too much, but what about a MLS metal crush gasket?

I appreciate the offer. I may take you up on that soon. I just ordered the new pan. I'm literally sitting out in my 86 in the parking lot of the local Subaru dealer as I type this.

I will be thinking outside of the box on this project.

Cheers!

A couple of the corners are too sharp and the sealing surface is small. Plus, the M6 screws would not provide enough clamping force for proper crush.


Of course! We are not too far from you and have two complete <200 mile FA24 engines (the second from a 2022 WRX) side-by-side, plus the complete car if you ever want to take a look.

Here's a vid of the new OEM pan. The bench it's on is 2" thick precision ground to .001" per ft.

https://www.youtube.com/watch?v=MLoct7MSqhk


A few locations on the upper pan at its narrowest are this width, just under half the diameter of the M6 threads...

https://killerbmotorsports.sharepoin...TBmSA?e=tsbQ6J

@KillerBMotorsport

Okay, I want to be clear on the details concerning this project, so I have a question to ask you.

The spacer plate that you are designing and describing in this thread is for the second gen cars. Researching the part numbers today, the lower oil pan for the FA24 for the '23 BRZ has a Subaru P/N 11109AA300, whereas the P/N for the first gen cars started at 11109AA220 and had been revised twice with part numbers 11109AA221 and 11109AA222 over the years.

So my question is: Does the lower oil pan have the same design and bolt pattern on the FA24 compared to the FA20 oil pan design in the first gen cars?

I want to take on the challenge of solving the oil pan sealant issue on the first generation cars before I take on the second gen cars, seeing how I don't own a second gen model.

If the patterns and design are the same, I'll keep this here for now as you may be able to use this information on this spacer plate project of yours. However, if the design and bolt pattern are new to the FA24, I will go ahead and start a new thread as I don't want to hijack this thread that you started with this frst gen project of mine.

If I can solve the issue of the first AND second gen oil pan sealing issue on these cars in one project, that would be ideal.

The bolt pattern is the same on both gen cars, but the design is somewhat different. The 'tub' part of the oil pan is different with some other subtle tweaks. These are not drastic changes. If I showed you each pan a week apart, you likely wouldn't see a difference big enough to note. Close inspection side-by-side and you will see the changes.

I'd bet a $20 that the FA24 pan will fit all FA20 cars, but I'd only bet $1 that the 1st FA20 pan design might fit an FA24. The FA24 exhaust manifold is closer to the oil pan than the FA20. Not sure if any of these matters for what you're doing, but there it is.

If the manifold is nowhere near the edges of the pan, we'll be in good shape. As long as the flange of the pan has not changed, we'll also be in good shape and I can continue solving both generation sealing issues with this one project.

Here's what I have determined to be the fault of the OEM design for this pan and its mating surface (the underside of the upper oil pan assembly):

The pan flange is designed simply to hold the lower pan in place to the upper pan while the sealant cures within the channel. It was not designed to squeeze a gasket and hold it in place to form a seal. Once the sealant cures, the two mating surfaces are basically "glued" together. This makes it so important for anyone performing a removal and re-installation of the pan, that in addition to bending the flimsy metal of the flange back into as close to a flat shape as possible, that they also must THOROUGHLY clean both surfaces completely, by removing ALL of the old sealant, as well as any oil or grease residue from within that sealing channel along the circumference of the upper pan, and the mating surface of the lower pan. This can be almost impossible to do (unless the engine is upside down on a stand) when you are constantly being plagued by drips of oil from the block.

If you have plenty of time, as in the case of the home mechanic, you can wait several hours for the drips to stop to begin the cleaning and resealing process, but do you really think that a dealer or independent technician has the time to do this? I don't think so. Subaru designed these engines so that they can be assembled in the cheapest and quickest way possible...for robots to do the work that human assemblers once did. Subaru DIDN'T design them to be worked on, disassembled and reassembled by human beings. They have basically engineered a "throw away" engine design.

[Rant]: You used to be able to buy a fractional H.P. electric motor in the United States that was actually made in the U.S. before all of the motor manufacturing companies decided to sell out to Chinese and Mexican companies. Ones that you could actually rebuild with new parts when they failed (the parts were also manufactured in the U.S.). They lasted longer because they were designed to. The quality control was much better. Now you buy a small motor off the shelf and they're ALL built somewhere else OTHER THAN the U.S. and they just don't last very long because of cheaper materials and insufficient (or a complete lack of) quality control. They are also built using cheap labor, which adds to the problem. "Minimum wage means minimum effort!" is a term I like to use when describing this problem. Anyways, NOBODY rebuilds small electric motors anymore when you can just buy a new one...and a second new one....then a third new one....then a fourth new one....and on and on whenever they fail. Designed Obsolescence is another term I like to use, and it's an idea that fills our landfills with extra waste that we have to deal with.
[Sorry, rant over.]

Anyways, this OEM engine sealing design with a lack of gaskets makes it more difficult and time consuming for the regular Joe, let alone the enthusiast to work on these cars. You may as well buy a new or used engine when yours fails just due the cost of labor to fix it. A well-designed alternative needs to be available for at least the racing scene, if not, for anyone else who works on these cars. I will do my best to take this one project on to solve this one issue. I don't let people who say "No, it can't be done." to me have the final word. I could point out my ECU flashing and tuning experience as an example, or even the Harman Kardon head unit issue that I was able to solve, but I'll leave it at that. I have faith that my simple idea will work. If it helps just one person, it will make a difference.

I'll be back around in about a week when my new oil pan arrives. Also, Fel-Pro apparently already makes an oil pan gasket for these engines, P/N OS3087 which I am trying to obtain one to use in helping creating a different one for this application design improvement. I am assuming their design doesn't take into consideration the flimsiness of the OEM pan flange and would leak when torquing the bolts to specifications, which is why I seem to have trouble locating one.

It might be more trouble than it's worth, but someone could weld in a 1/8" high sheet metal wall (or fence) around the inside of the pan where it meets the upper pan. This could prevent sealant from pushing into the crankcase galley.

Interested in the original idea, pardon if I am off my rocker... but are the images broken in the original post? Personally have no need for the extra ports, as I have my oil temp into the block and no plans for boost :P. At a $149 price point consider me locked, would love to be able to just dump in a 5+1 oil change into the engine :happyanim:

I think you are in the majority, so we'll include plugs for those ports. :thumbup:

I think it's because the images are hosted on sharepoint.com and it requires some kind of third party cookie be set before you see them.

I have trouble seeing most of killerb's images as well. I got it working once, but they are broken again.

Edit - yeah - whitelisted ft86club.com to allow 3rd party cookies and it seems to work again.

The spacer is a neat idea, I'd be on board for 1st gen.