Potential Cause of rumored GR86’s blown engine? Seal packing(RTV) was peeled off

[Tcoat]

Originally Posted by whiplash willy

Kevin Vo's video he posted today on the FTspeed channel, on the partial engine tare-down has some good visuals on the excess RTV in other parts of the engine, like the timing cover and valve covers. It makes me think that dropping the pan to redo the RTV might be a bit pointless considering how much excess RTV is on the other larger surfaces.

Oh if only somebody had mentioned this before instead of everybody fixating on the oil pan!

[Petah78]

Originally Posted by whiplash willy

Kevin Vo's video he posted today on the FTspeed channel, on the partial engine tare-down has some good visuals on the excess RTV in other parts of the engine, like the timing cover and valve covers. It makes me think that dropping the pan to redo the RTV might be a bit pointless considering how much excess RTV is on the other larger surfaces.

I actually went online and looked at some of the photos of a FA20's timing cover and form the ones that i have seen, the RTV applied is not much different from the ones posted by Kevin Vo's FA24. Likewise with the oil pan.

[NoHaveMSG]

Originally Posted by Petah78

I actually went online and looked at some of the photos of a FA20's timing cover and form the ones that i have seen, the RTV applied is not much different from the ones posted by Kevin Vo's FA24. Likewise with the oil pan.

I've had 3 apart. One was done by a second grader,....I mean Toyota master tech and it was a mess. The two stock ones looked about the same as that video.

[Petah78]

Originally Posted by KillerBMotorsport

The open area of the holes is larger than the OEM pickup's mesh, but chunks of RTV as shown in this thread will definitely be stopped by this pre-filter. Tough to see, but the external surface is also not flat (OEM is flat), so when the engine stops chunks can more easily fall away than on a flat surface vs stick to it. And being all external, much easier to clean than using a borescope, mirrors, and picks. There is also a LOT more open area on this pre-filter, so it would take a lot more RTV stuck to it before it will have any significant effect on flow.

Auto/Oil rated grade of Nylon. We've used them a lot from AOS', water pump inlets, and oil pans. The newer printing materials and process capabilities have come a long way. I never would have dreamed of bolting on printed plastic parts for real world testing 25 years ago!

Has this been tested in the wild? Would this actually make it into PROD? Cost? Thanks.

[whiplash willy]

Originally Posted by Tcoat

Oh if only somebody had mentioned this before instead of everybody fixating on the oil pan!

Yes true, it was mentioned before, but this is the first visual I have seen of it.

I think it makes sense to drop the oil pan to clean the pickup in some cases, but with all of the other areas of excess RTV, the oil pan is just a drop in the bucket.

[soundman98]

a splash in the pan as some might say...

[Tcoat]

Originally Posted by whiplash willy

Yes true, it was mentioned before, but this is the first visual I have seen of it.

I think it makes sense to drop the oil pan to clean the pickup in some cases, but with all of the other areas of excess RTV, the oil pan is just a drop in the bucket.

Ya sorry. My post was supposed to be a tongue in cheek joke but came across more like a whine.
Yes this supports much of what has been said and I appreciate seeing it. That valve cover shows exactly how chunks can be introduced after the oil filter. They would be a bigger concern than what is ever found in the pan.
Still doesn't go far enough because there are at least two more colours of sealant used someplace. Would require a complete tear down to find where they are coming from though.

[KillerBMotorsport]

Originally Posted by Petah78

Has this been tested in the wild?

Not yet, but very soon.

Originally Posted by Petah78

Would this actually make it into PROD?

Always depends on testing and demand. Without both, there is no production.

Originally Posted by Petah78

Cost?

Tough to say this early on without an idea on demand/volume. I will speculate ~$49 but don't hold me to it.

Originally Posted by Petah78

Thanks.

Of course! Just doing what we do

[KillerBMotorsport]

I'm assuming the RTV shedding reduces over time? Have any FA20 owners documented this? I didn't have plans to, but we'll likely be dropping the oil pan a lot on our mule a lot. I actually have spare complete engine here with 380 miles on it that I can drop the pan on to see if there's anything that early on. Shop car pan will be coming off soon and it has some miles on it.

[Tcoat]

Originally Posted by KillerBMotorsport

I'm assuming the RTV shedding reduces over time? Have any FA20 owners documented this? I didn't have plans to, but we'll likely be dropping the oil pan a lot on our mule a lot. I actually have spare complete engine here with 380 miles on it that I can drop the pan on to see if there's anything that early on. Shop car pan will be coming off soon and it has some miles on it.

It "should" reduce. There is only so much that can be shed and it is most likely to break off early rather than later.
Be interesting to see what is in the filter after a couple of oil changes (Petah you changing again soon?)

[Petah78]

Originally Posted by KillerBMotorsport

I'm assuming the RTV shedding reduces over time? Have any FA20 owners documented this? I didn't have plans to, but we'll likely be dropping the oil pan a lot on our mule a lot. I actually have spare complete engine here with 380 miles on it that I can drop the pan on to see if there's anything that early on. Shop car pan will be coming off soon and it has some miles on it.

I would assume that most of the RTV will have dislodge itself early in the engine's operations. It would be interesting to see what you find you in your engines, please keep us apprised.

Originally Posted by TCoat

It "should" reduce. There is only so much that can be shed and it is most likely to break off early rather than later.
Be interesting to see what is in the filter after a couple of oil changes (Petah you changing again soon?)

Unfortunately not. It's getting cold here in the great North and the car is going to be parked in a couple of weeks. Oil only has 2k kms on it so likely will be changed in the spring. I will however dismantle the oil filter again then and examine, i am not expecting to find anything in there this go around though.

[Tcoat]

Originally Posted by Petah78

I would assume that most of the RTV will have dislodge itself early in the engine's operations. It would be interesting to see what you find you in your engines, please keep us apprised.



Unfortunately not. It's getting cold here in the great North and the car is going to be parked in a couple of weeks. Oil only has 2k kms on it so likely will be changed in the spring. I will however dismantle the oil filter again then and examine, i am not expecting to find anything in there this go around though.

Be willing to bet that there will not be much if any after the first oil change.

[Dzmitry]

Originally Posted by KillerBMotorsport

AVCS. IIRC it's ~5K RPMs (under load/WOT) where the cams transition. The oil feed that supplies AVCS draws more oil, and the system pressure drops some. All Subaru AVCS engines do this: EJ20/25, FA20/24. The only time pressure climbs fairly linear with RPM is when AVCS is deleted.

These pumps don't cavitate, at least not up to 10K RPMs. Aeration typically happens when the pump is bigger than the lubrication system is designed for... Like putting an oversized pump on a stock (or built to stock specs) block. That only pushes more oil through the bypass valve, eventually aerating.

I appreciate the simple conclusive response after years worth of debates on this forum about this subject. Where were you all this time??

[NoHaveMSG]

Originally Posted by Dzmitry

I appreciate the simple conclusive response after years worth of debates on this forum about this subject. Where were you all this time??

We certainly beat that subject to death like it owed the admin vender fee money.