The 6 Quart Oil Pan Spacer - Gen 2

[FR-S2GT86]

Originally Posted by KillerBMotorsport

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.

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.

[pope]

Originally Posted by FR-S2GT86

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.

[KillerBMotorsport]

Originally Posted by Breadman

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

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!

Originally Posted by blsfrs

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?

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.

[KillerBMotorsport]

Originally Posted by FR-S2GT86

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.

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

Originally Posted by pope

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.

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

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.

[blsfrs]

Originally Posted by KillerBMotorsport

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.

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

[KillerBMotorsport]

Originally Posted by blsfrs

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...

[FR-S2GT86]

Originally Posted by KillerBMotorsport

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

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



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.

[Tcoat]

Originally Posted by FR-S2GT86

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.

[KillerBMotorsport]

Originally Posted by FR-S2GT86

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

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 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.

[dragoontwo]

Originally Posted by KillerBMotorsport

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 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?

[FR-S2GT86]

Originally Posted by KillerBMotorsport

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 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.

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!

[KillerBMotorsport]

Originally Posted by dragoontwo

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

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.

Originally Posted by FR-S2GT86

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!

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.

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

[FR-S2GT86]

@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.

[KillerBMotorsport]

Originally Posted by FR-S2GT86

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?

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.