Summer Plans

Ok, so here is the layout. I have a 1996 Legacy GT and a 1999 Outback SUS. the GT is currently my DD but both cars need to go under the knife this summer. The GT has 232k miles and is a junkyard salvage car unknown date of last timing belt. The SUS had the last timing belt done around 100K miles and 10 years ago. So the plan is to end up with one running by the end of the summer. To achieve this I have picked up a 2000 Ford Ranger to DD while my GT is down. I want to do a High Compression Frankenmotor (HCF) with 96 block and 99 heads. The dilemma is which car receives the motor? So more car info.

 

96 Legacy GT

232K miles

2.5 Auto

2" lift in front 2.5" lift in back

Salvage Title (Excuse for Stupid!)

04WRX Front Brakes w SS lines

04 Legacy H6 Rear Brakes w SS lines

Moderate interior

Upgraded Speakers

No Known Running Problems

Trunk damage where PO backed into something

No Sunroof

Fresh Headlight and Taillight assemblies

End goal TOY with Eaton M90 and Low Compression Frankenmotor (LCF)

 

99 Outback SUS

140K miles

2.5 Auto

Stock Suspension

Clean Title

Stock Front Brakes

Stock Rear Brakes

Beautiful Interior

Stock Speakers

Overheated resulting in no start (also why I got it for cheap)

Trunk damage where PO backed into something (facepalm)

Sunroof

Headlights and Taillight assemblies need replaced

End goal - decent family car with the HCF

 

The biggest part of the question here is which ECU would run the HCF easiest? The plan is to end up with one high compression and later build a LCF with the other parts for boost. I love my GT and putting the HCF in it to keep it as my DD until I do the LCF to swap was my first idea. It would be simpler long term to put my GT down and install the HCF into the SUS and wait for the LCF to put into the GT. I have no problem swapping most parts between both cars to get one to have the best of both worlds. I do not want to swap the body parts or interior between them.

 

Basically I am just looking for advice. I will have the 99 heads looked at by a machine shop and if needed (most likely) rebuilt. I also should rebuild the 96 block. I love to read so shoot me some links that you think are informative to the HCF build and thank you for your help.

Actually the stock ECU should run the High Compression Frankenmotor without issue. The low compression frankenmotor on the other hand will require a standalone ECU due to the boost.

Based on what I have read on one of your posts, the 99 is a unique wiring experience. Which is why I was curious about which ECU would run it best.

The only thing unique about the 99 is that the EJ22 is a Phase II engine and electronics, so nothing from prior years will swap into it easily without changing a lot of the wiring. In the case of the 99 EJ25, it's already a frankenmotor on it's own. It combines a Phase II block with Phase I heads from the 97+ EJ25D. The pistons are Phase I and the crank is a Phase II. The compression ratio of a 97-99 EJ25 motor is 9.7:1. If you have a 99 Legacy or Outback with the 2.5, any Phase I motor will fit into the car, which is why many put the EJ22E from the 95-98 Legacy into that as a more "reliable" replacement.

 

A good combination for the HCF build is to go with an EJ251 block and use EJ22T or EJ25D heads using the 0.7mm 2.5 SOHC head gaskets. That combination will get you about 11.4CR with the 22T heads and 10.4CR with the 25D heads. This is about the highest CR you can get without changing the ECU to Standalone. There are 14:1 builds out there, using the EJ22E engine, EJ25 crank, and EJ20 heads, but that requires a standalone ECU.

 

For a LCF combination, you'll want to source an EJ22T block and then use the 25D heads and a Cometic C4261-060 head gaskets (the thickest gaskets you can buy) which will give you an 7.5:1CR. You're going to need a standalone ECU to run boost on it though.

Any advice on oiling upgrades? I read something about using an sti 11mm oil pump. (Hard drive failure lost all my bookmarks)

 

Also benefits of alternate waterpumps? I want to be reliable+ when finished.

 

Advice to reduce chances of head gasket failure?

 

 

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You have 2 good options for 2.5 hybrids at your disposal.

 

'96 25D heads + '99 25D block = cheap low comp 2.5L

'99 25D heads + '99 25D block = cheap high comp 2.5L.

 

Also, you will not want to use an 11mm oil pump on either of those engines. The flow and pressure are both too high and are engineered for EJ's that have AVCS. A 10mm EJ205 oil pump will suffice, and you will also want to use Moroso oil pickups and the latest STi oil pan to follow up for great oiling ability.

 

You will also want to swap to an '06+ EJ251/3 water pump and pump housing along with an EJ257 timing belt kit with the bracket that has the extra roller on it.

'06+ EJ251/3 water pump and EJ257 timing assembly.

http://i172.photobucket.com/albums/w40/Kenshin1984/1996%20Subaru%20Legacy%20LSi/received_1221016234619035_zpsbymkzcbw.jpeg

 

How to reduce head gasket failure? Make sure to get all mating surfaces prepped before installation. I also employed something I have never seen anyone else do before: Add 2 lower straight pins on each side. The passenger side will likely need machining, as mine did.

http://i172.photobucket.com/albums/w40/Kenshin1984/1996%20Subaru%20Legacy%20LSi/20170322_221737_zpszebad3ac.jpg

 

The '96 GT ECU, which should be a 9P, is trash, but will run a boosted engine well at 8psi. Use that for your low comp supercharged 2.5 and use the far more advanced '99 ECU for the SUS. You kinda' have no choice, really, as the ECU's will have trouble communicating with some devices in mismatched cars, which will cause CEL's to be thrown.

 

You do not, I repeat, DO NOT want to use Phase 1 EJ22 heads on an EJ25 of any kind without intensive work, like cams and porting. Phase 1 EJ22 heads breathe like crap and that will be an asthmatic EJ25 you will have constructed if no work is to be done.

 

EJ22T blocks with EJ25D heads are okay, but have horrible flame propagation properties, along with a compression ratio too lethargic for daily usage. '97-'98 22E pistons in a 22T block or shaved EJ22T pistons flush with the deck will be your best combo without having to put down extra coin on aftermarket pistons.

I was actually thinking of your build when I asked all three questions. Thank you for responding.

Also my hope was to end up with the LCF-SC in the GT and the HCF in the SUS so thank you for the note on my GT comp being better for low boost.

Has anyone active used ARP head studs? http://www.arp-bolts.com/kits/ARPkit-detail.php?RecordID=1752

 

I did read an Amazon review stating that these are for turbo blocks. Can anyone verify differences?

 

I am thinking of the pin addition DOHCEJ22E1 did and suggested with these. I am planning on building the HCF this summer.

 

Question/assumption. Setnev in your Rock Auto valve cover "rant" you list the different valve covers used over the years. I was wondering if you would know offhand if you can swap valve covers between heads? I am assuming you cannot but I have not pulled a Subaru engine yet.

I looked into replacing my stock bolts with the ARP ones when I did my build but if I remember right it was $200+ per bank so I wasn't really looking forward to dumping $400 ish in overkill hardware. I'm sure it would have it's benefits for a boosted motor but at what power/pressure does it really warrant that much money for bolts? Also the valve covers do have minute differences but you can usually still swap them without issues, I think currently I have a 98 and a 96 valve cover on my 96 2.2 and it's no problem.

ARP bolts should only be used in high boost applications. If you're building a N/A motor, stock head bolts will do just fine.

+100 on Setnev. I reused the head bolts to my EJ22D, if that says anything.

+100 on Setnev. I reused the head bolts to my EJ22D, if that says anything.

 

Same here. Bolts weren't stressed, so I reused them. Glad to know I'm not the only one.

Thanks for the replies. Since the HCF will. Be the daily driver I didn't want any failures. But I also would rather not spend wasted money.

 

 

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DOHCEJ22E1 do you have a part number for the oil pump? Also if I can get verification on part numbers by anyone it would be awesome.

Links for the timing belt and water pump.

07 Legacy 2.5i

Gates 42571 Water Pump https://www.amazon.com/dp/B0031GRO5Y/ref=cm_sw_r_cp_api_hrdzzbKWNNK59

96 Legacy GT 2.5

Gates TCK277 Timing Belt Component Kit https://www.amazon.com/dp/B000C2YDP4/ref=cm_sw_r_cp_api_LrdzzbTP5EB1P

 

 

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For part number verification.

04 WRX 2.0 oil pump

 

Subaru 15010AA300 Engine Oil Pump https://www.amazon.com/dp/B00IGZQ866/ref=cm_sw_r_cp_api_bqnzzbQATZE5P

 

 

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