High Compression Frankenstein

[Ej22D]

Originally Posted by no694terry

you had me doing all kind of homework on ej20e's yesterday. wondering if theyre a cheap block replacement for ej205's with just a piston swap.

They are. Rods are 52mm at the journals, pistons are the same diameter, and wrist pin locations match up. The only two things that are different is block density (Phase 1 blocks are tougher) & the main thrust bearing locations are different between them (Phase 1 has it in Position 3, Phase 2 has it in Position 5).

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[DrrrD]

Originally Posted by t3hWIT

and i live in central Pa, aka Penntucky. the closest thing to an engine builder we have is the neighborhood mechanic, or some guy at AAP who'll gather the parts together. The biggest thing in tuning around here is slapping a big ol aluminum wing, stick on hood scoops, chrome exhaust tips, and APC spinner wheel covers. I'm interested in performance and teaching these tuner wannabes a lesson in real cars. But since I'm one of the few and proud, i dont have access to this stuff. just junkyards. ugh... i hate this region...

***128514;***128514; that's incredibly true...

[DrrrD]

Originally Posted by greg donovan

do what i amp planning:

phase II ej25 shortblock with the older dual port ej22 heads and the thick ej25 gasket. should get you right around 11.5:1. any higher and you would need to possibly add a piggyback to retard the ignition timing or add water injection or find a way to increase the fuel or all of the above.

Slowly but surely these replies are blowing my mind... GG... I need to build a new engine

[Kostamojen]

Now that there are EJ202/203/204 motors around for cheap in the US...

Has anyone tried JDM EJ20 SOHC heads on a EJ25 block yet?

[HamFist]

[no694terry]

Originally Posted by Kostamojen

Now that there are EJ202/203/204 motors around for cheap in the US...

Has anyone tried JDM EJ20 SOHC heads on a EJ25 block yet?

Not yet but my brother should blow his up soon enough. They're non avls. So I'm betting they're very similar to ej222 heads

[Kostamojen]

Well I might be the first to try. I did wind up buying an EJ202 for cheap, took it apart to take a look at the heads and I'm having a valve job done right now.

The valves do appear to be slightly smaller, but the heads are very similar to a SOHC EJ25 circa 2000 as opposed to EJ22 heads. Haven't measured the CC's yet to see how big of a difference is there with the compression ratio.

Original plan was to run these heads with the 2.2 block, but after doing an oil change and having the motor throw a pulley, its got a ton of bearing material in the oil. So I'm going to have a 2.5 shortblock built, probably with .25 oversize pistons and an STI crank. Going to add an OEM oil cooler to the mix, maybe add a Killer B oil pan but not too sure yet. Would be nice to get a WRX ECU to work too, might call up IWire and see if they can make a harness... Supposedly its easier to get that ECU to work with the '99 due to MAF and similar sensors.

[kayaker43]

Hey guys, Im struggling to put together some EJ22 dual port heads with roller rockers and solid lifters. I have a set of rebuilt heads but they are the flat pad style.

My goal is to run the Delta 200 torque cams in my Frankenmotor. and they only work with the Roller rocker setup.

Can anyone point me to a source for the 97-98 rockers and cams or even complete heads. I'm going nuts looking for them.

[franklinstower]

Originally Posted by kayaker43

Hey guys, Im struggling to put together some EJ22 dual port heads with roller rockers and solid lifters. I have a set of rebuilt heads but they are the flat pad style.

My goal is to run the Delta 200 torque cams in my Frankenmotor. and they only work with the Roller rocker setup.

Can anyone point me to a source for the 97-98 rockers and cams or even complete heads. I'm going nuts looking for them.

I find them in the pick and pull yards all the time. They are abundant here in washington anyway.

[Tampa Bay Automotive]

I recently blew up my 9-2x's EJ253, I don't know what went wrong yet but i think its a problem with the head.

So while I have the engine out of the car anyway i figure i might as well build in some power.

With that:
Would it be possible to put 2.2 heads on a 2005 EJ25?
if so, what do I need?
If not 2.2 heads, then what? I'm trying to avoid WRX/AERO swaps or Raptor SC

[LubySuby]

So my son & I built this engine last week using info from this thread and particularly @Matt Monson and I am curious what others closer to sea level are using for ignition coil, wires, and spark plugs in their franken engines.

At 7200', we are currently using the factory NGK V-Power(BKR6ES) spark plugs gapped at .044". The car is definitely running a bit 'fat' here in WY, but I'm curious as to the performance at sea level as he's driving this to WA for the summer. We can generally get away with very high compression and very large camshaft profiles at this altitude, but I know sea level will affect performance. I will be inspecting the plugs today for heat deficiencies etc. I will most likely swap in at least an iridium plug but am wondering what you guys are running.

The Car:
1993 Legacy L
2001 Phase II 2.5 Block, 1991 Phase I 2.2 heads, mild port, factory cams (for now),
Fel Pro .023" head gaskets, NGK plugs, factory '93 type ignition wires, factory '93 coil,
Phase I intake, cam pulleys, crank gear, sensors, and timing belt.
2001 oil pump, tensioner, water pump etc.
No header, cats still installed (for now), 2.5" cat back, no muffler or resonator.

BTW, the car runs much better than the stock 2.2. Much more torque, even at high altitude.

[704_bugeye]

Originally Posted by LubySuby

So my son & I built this engine last week using info from this thread and particularly @Matt Monson and I am curious what others closer to sea level are using for ignition coil, wires, and spark plugs in their franken engines.

At 7200', we are currently using the factory NGK V-Power(BKR6ES) spark plugs gapped at .044". The car is definitely running a bit 'fat' here in WY, but I'm curious as to the performance at sea level as he's driving this to WA for the summer. We can generally get away with very high compression and very large camshaft profiles at this altitude, but I know sea level will affect performance. I will be inspecting the plugs today for heat deficiencies etc. I will most likely swap in at least an iridium plug but am wondering what you guys are running.

The Car:
1993 Legacy L
2001 Phase II 2.5 Block, 1991 Phase I 2.2 heads, mild port, factory cams (for now),
Fel Pro .023" head gaskets, NGK plugs, factory '93 type ignition wires, factory '93 coil,
Phase I intake, cam pulleys, crank gear, sensors, and timing belt.
2001 oil pump, tensioner, water pump etc.
No header, cats still installed (for now), 2.5" cat back, no muffler or resonator.

BTW, the car runs much better than the stock 2.2. Much more torque, even at high altitude.

I just recently bought a 95 impreza L and I'm wanting to do something very similar to what you did. Ihave several questions for you.
1 Are you running a 2.5 harness or 2.2?
2 which ECU are you running?
3 are you running knock sensors?

[Kostamojen]

So my unique Frankenstein build (Built at M45 Automotive) is in progress...

Cylinder heads: JDM EJ202
Block: Rebuilt EJ22 (new pistons, rings, King bearings, crank, etc.)
Add ons: Killer B oil pan, OEM oil cooler, 10mm oil pump

The purpose of this build is to get a slight compression bump, convert over to dual port exhausts from the EJ22 single ports, and get as much reliability as possible for long term heavy duty use. I went with the JDM EJ20 N/A engine because its a Phase II head with dual ports rather than a Phase I, plus the intake manifold and all emissions components bolt up identical. I thought about an EJ25 block to go with the heads, but was concerned the compression change might be too much compared to the other Frankenstein combos.

Pics so far:

[tipsymechanic]

Originally Posted by Kostamojen

So my unique Frankenstein build (Built at M45 Automotive) is in progress...

Cylinder heads: JDM EJ202
Block: Rebuilt EJ22 (new pistons, rings, King bearings, crank, etc.)
Add ons: Killer B oil pan, OEM oil cooler, 10mm oil pump

The purpose of this build is to get a slight compression bump, convert over to dual port exhausts from the EJ22 single ports, and get as much reliability as possible for long term heavy duty use. I went with the JDM EJ20 N/A engine because its a Phase II head with dual ports rather than a Phase I, plus the intake manifold and all emissions components bolt up identical. I thought about an EJ25 block to go with the heads, but was concerned the compression change might be too much compared to the other Frankenstein combos.

Pics so far:

Beautiful! These Frankensteins really intrigue me, especially when I had my RS

[indevolatile]

I have a 2001 Impreza Outback Sport with a phase 2 2.2 engine. With over 250,000 miles, it's developed a little bit of a knock and I'm about a week into research on the easiest/best way to go about getting a new short block.

From what I've gathered, I can:

A) reuse my current heads on another EJ22 (phase 1 or phase 2), or on an EJ25D, or EJ251 (but not EJ253, as I read a reference to domed pistons on the EJ253 causing problems)

or

B) swap in an entire EJ251 or EJ253 using my stock wiring, as long as I switch over my phase 2 Ej22 cam sprockets onto the new heads.

Does this sound right?

I just want to broaden my search as much as possible, without having to rewire my car. Would an EJ251 block with my EJ22 Phase 2 heads be the best solution, as mentioned in post #329 of this thread?

[Kostamojen]

Bumping the famous Frankenstein post because I purchased a $500 '97 Wagon that needs an engine (came with a motor that had its crank pulley WELDED on and wobbly, crank and shortblock are ruined) and I wanted to go through absolutely all the information available in order to decide what to do with an engine for this car. It also came with EJ22E heads (dual port) and not EJ22EZ heads (single port) like it was supposed to, so this is a good opportunity to try another Frankenengine...

Anyway, I have a set of EJ203 heads sitting around, along with a EJ251 head I borrowed from a friend, plus these EJ22E heads. I decided to measure the combustion chamber volume myself to confirm numbers online, plus get numbers for the 203 since nobody has done that yet.

I'd like to eventually get my hands on an EJ18, EJ22EZ and EJ221 head to get measurements on those too, as well as get the cams/lifters off the EJ22EZ head for my EJ22E heads. Here is the page with all the information I've collected so far:




Let me know if you have any first hand measurements, especially for piston volumes and deck clearances. Those are really hard to get numbers for.

I wanted to go over some differences that are mentioned a lot but never really shown, especially between the Phase 1 and Phase 2 SOHC heads. This information is readily known by people who have worked on these motors, but I'd like to document it so people that don't have the engines in front of them can understand.

Phase 1 heads have limitations, mostly due to the location of the spark plug tube directly impacting and limiting the intake port size and shape. The fact that the cams have to slide through the head casting itself with Phase 1 SOHC heads means the maximum lift of the cam is limited. Phase 2 heads with the separate cam carrier case lets them run significantly more lift on the cams, including large lobes for aftermarket cams.




I wanted to go over some information about the EJ202/3 heads that isn't discussed much. 202 and 203 heads are fundamentally the same from what I know, as the first motor I purchased awhile back was an EJ202, and the second was an EJ203. These heads are the same design as EJ251 heads, but with smaller valves, 3cc less chamber volume, and cams that have less duration but the same lift. The intake port is slightly smaller with the EJ202/3, but the exhaust port is the same.





Finally, I wanted to go over theoretical builds using Phase 1 heads on an Phase 2 block...

My first use of mixing blocks is mentioned in this thread, running EJ202 heads on an EJ221 short block. Compression wise, this combination reduced chamber volume by 3cc. According to what math I could do, this would bump the compression from 10.0:1 to about 10.5:1. A nice mild bump in compression. However, there is a reduction in valve size supposedly, as well as possible differences with the cam shaft. The engine is still running with two different new owners and running well, so I would consider this a successful "mild" Frankenstein engine, with the ability to change out to dual port headers rather than the EJ221 single ports.

My second use was running EJ18 heads on an EJ203 short block. This is supposedly a reduction of 7cc to chamber volume, but I haven't actually measured the EJ18 heads. Theoretically this would bump compression to around 11.0:1 according to what math I could put together. It was a very healthy motor, and did a couple track days + autocross days with it before removing it for a WRX swap. I even had it dynoed:




Looking at my EJ22E heads and my options for the '97 wagon, the chamber is plenty small enough to clear the cylinder walls and gasket from an EJ20.



This means that EJ22E, EJ22EZ and EJ18 SOHC heads should all be able to be used on an inexpensive JDM EJ202/3 in order to create a higher compression motor utilizing Phase 1 equipment. SUPPOSEDLY EJ18 heads have the same CC's as EJ22E/EZ heads, but I can't confirm that until I have one in front of me.

As the rest of this thread has gone through, running Phase 1 heads on an EJ221 or EJ251 short block bumps the compression ratio to 11.5:1 or even higher. EJ221's can only be bought at junkyards now, and JDM imported EJ251's are twice the price of EJ202/3's now, and you can buy a new EJ251 short block for $2k from Subaru.


Also a note... For those who run or want to run EJ251 heads on EJ22 short blocks, the chamber diameter won't be too large for the headgasket/cylinder walls of the 2.2l short block. However, there is NO REDUCTION of compression ration as supposedly the EJ221 and EJ251 have the same chamber volume. I need to measure an EJ221 to confirm this though.

[arse_sidewards]

So is the 2cc piston dish reduction from the EJ22E2 to the EJ22E3 the difference between valve interference and not? Or did the cams grow some extra lift at the same time?

Thank you for doing the work to compile all that info in one place.

[Kostamojen]

Originally Posted by arse_sidewards

So is the 2cc piston dish reduction from the EJ22E2 to the EJ22E3 the difference between valve interference and not? Or did the cams grow some extra lift at the same time?

I don't have any actual information about the differences with those two, other than the higher compression ratio stated by Subaru, and that it has been stated the final phase 1 head EJ22 single exhaust port engine possibly has a phase 2 short block?

My assumption is there is a change in piston design. Quick check of part numbers states the pistons are specific for 97-98.

[arse_sidewards]

Originally Posted by Kostamojen

I don't have any actual information about the differences with those two, other than the higher compression ratio stated by Subaru, and that it has been stated the final phase 1 head EJ22 single exhaust port engine possibly has a phase 2 short block?

My assumption is there is a change in piston design. Quick check of part numbers states the pistons are specific for 97-98.

I did a crude but unnecessarily thorough comparison of ej22 and 25 pistons on Rockauto, wrote up a giant wall of text and then trimmed it down to the following conclusions:

The small end of the rod seems to stay the same as one pin bushing covers all EJ applications. Therefore basically any EJ25 other than the Phase 1 DOHCs with 48mm journals can be made non-interference and comically low compression using EJ18/20/22 rods. Compression can then be dialed back up with selection of piston (the EJ25D1 is particularly interesting in this regard since it uses a huge dish and short rod so the piston must have a high compression height to result in the same stock compression as later EJ25s), head gasket and cylinder head until you get what you want.

Which in my case is would be that is cheap and "just works" in a 90-94 Legacy without much difference in external parts or maintenance schedule (i.e. perpetual neglect) from the other three in the fleet

Disclaimer: USDM only, I didn't even glance at the JDM part of the spreadsheet.

[Kostamojen]

Originally Posted by arse_sidewards

I did a crude but unnecessarily thorough comparison of ej22 and 25 pistons on Rockauto

BTW if you use Subarus part site, parts.subaru.com it shows what exact models use what part when you find specific part numbers. There is a little pull down menu on pages with part numbers. Really good tool for figuring out these kinds of things.

[arse_sidewards]

Originally Posted by Kostamojen

BTW if you use Subarus part site, parts.subaru.com it shows what exact models use what part when you find specific part numbers. There is a little pull down menu on pages with part numbers. Really good tool for figuring out these kinds of things.

I know. I prefer and default to using Rockauto specifically because you can often infer extra info from seeing how multiple manufacturers list their parts. Not sure if the difference mattered in this case.

[built4rally]

I think I know the answer but did Subaru change the location of the keyway, degrees wise, on any of the crank shafts ever? I am having trouble with my ej251 bottom end/ej22e head hybrid build, it would idle on cold start but as soon as it warmed up or it was given any throttle it would stall out. The shop I have working on it now says that my 251 from an 03 forester has the keyway "in a different spot" so the ignition timing is off. At this point i'm a bit fed up with it after several weeks of diagnosing it myself and chose to throw a Haltech elite 550 at it to save time and headache.

[Kostamojen]

Originally Posted by built4rally

I think I know the answer but did Subaru change the location of the keyway, degrees wise, on any of the crank shafts ever? I am having trouble with my ej251 bottom end/ej22e head hybrid build, it would idle on cold start but as soon as it warmed up or it was given any throttle it would stall out. The shop I have working on it now says that my 251 from an 03 forester has the keyway "in a different spot" so the ignition timing is off. At this point i'm a bit fed up with it after several weeks of diagnosing it myself and chose to throw a Haltech elite 550 at it to save time and headache.

Did you use the crank gear from your ej22e?

[built4rally]

Originally Posted by Kostamojen

Did you use the crank gear from your ej22e?

The 03 forester ej251 had the exact same crank gear as the 91 legacy ej22e.