Best Power/Gas Milage Compromise JDM NA Engine?

carlito · Post by **carlito** » Thu Dec 29, 2011 2:31 pm

Hi peeps,

I have been lurking in the shadows around here for many months now. Reason being I own an '89 JDM Legacy 2.0 vz. manual, Fwd, Non turbo. I need your expertise. Recently a shady mechanic screwd with my engine during an overhaul job resulting in a blown short block a few months later.

I want to buy another engine but I doubt I can find a low mileage first generation engine. My current engine is an ej20d. Makes 150 hp@6800 redlines at 7600 rpm. I would like to know which would be the very best replacement NA engine that develops 150 hp or more and gives combined milage of atleast 27 mpg.)

This car is my daily driver so It has to be economical and reliable. Can the newer ej204 fit in an my car and safely work with my manual transmission? This is a legacy JDM 190 hp NA, AVCS engine. My transmission type is TM752RD1AA.

This newbie will appreciate any advice..

evolutionmovement · Post by **evolutionmovement** » Fri Dec 30, 2011 12:01 am

An EJ22 could probably manage what you're looking for. On paper, it might be rated as less than 150 hp, but I think they measured in Clydesdales while their contemporaries measured in Shetland ponies as I never had a problem blowing off lighter cars with "150 hp" and holding my own past highway speeds against more powerful cars with my early EJ22 rated at only 130 hp. It's the fairly substantial bottom end that kills them.

That said, where are you located? Sounds like you're not in the US, so an EJ22 wouldn't be as easy to find. 27 mpg combined would be even easier if you're talking imperial gallons! I don't see why the EJ204 wouldn't fit your transmission as the EJ blocks are very much the same. You might have to play around with the starter or something, but it won't be anything difficult. How well the transmission will handle the power is more the question. Seeing as you're FWD, that isn't huge power, and the torque won't be massive, so you'll PROBABLY be OK. I find that engine interesting myself. If it weren't for the high test fuel requirement, I'd love to put one in a lightweight car.

carlito · Post by **carlito** » Fri Dec 30, 2011 9:56 pm

Thanks for the info, I live in Kenya and you are right, the ej22s are hard to come by around here. We have plenty old generation ej18s and ej20s, and rarely the ej25s.

I am a little nervous about purchasing any pre MY 1996 engines (especially since theres no foolproof way of verifying the condition of a used motor short of tearing it apart, or is there something I should be looking out for?)

Thats why I was toying with the idea of dropping in a late model ej204 engine . You mentioned I would have to modify the starter, how about sensors such as oxygen sensors? will it fit in the exhaust socket? My car has one sensor, how do i fit the second o2 sensor? Since my current is OBD1 what else will I need to change apart from engine and ecu? Will I need to swap my gauge cluster? My car is pretty light about 1,200 kg and with power to weight ratio is 126bhp/ton. I could squeeze 12 km per litre. :)I need to maintain or better this economy and power.

evolutionmovement · Post by **evolutionmovement** » Sat Dec 31, 2011 12:24 am

Any used engine is a gamble. That said, the insides of these engines are extremely tough. The short, 5-main bearing crankshaft and rods are forged, the bearing sizes are overkill for normally aspirated engines. I tore mine down with about 250k abused miles with infrequent oil changes (though I use synthetic oil) and the bottom end looked great. The bearings looked used, but I would bet they had another 100k in them. Journals were perfect. The top end looked almost like brand new. Sticking with another OBD1 car would be easier than rewiring to OBD2. You'll need the harness as well as the ECU, but beyond that, someone who's done the work would have to comment. From what people who have done it say, it's a lot of work, but some people don't mind that kind of thing. The O2 sensor is the least problem, and they all have the same thread. If you wanted to instal a 2nd one to your exhaust, you could just have an O2 bung welded to your pipe.

Basically, the best thing to do with any used engine is check the dipstick for relatively clean oil and make sure it turns over. Removing the valve covers is quick and easy and you can get a little idea of the condition by how the valve train looks. Knowing the mileage is good, too, but low mileage isn't as important as it is with some other manufacturers. If you get a new engine, replacing the gaskets, timing belt, water pump, and timing belt tensioner would be great as that will put you back to square one in terms of maintenance schedules and save you possibly having to do them once you've gone through the work of swapping engines. To me, if the oil doesn't look sludged or mixed with coolant (not common with these engines anyway), it turned over, and the valvetrain looked decent, I wouldn't worry about the mileage. I would guess the older engines are cheaper anyway and that money you save can go to replacing gaskets and such. I bought an EJ22T with 173k miles and the inside of that looks fine, though I only removed the heads, so I can't speak for the bottom end, but it doesn't concern me.

carlito · Post by **carlito** » Sun Jan 01, 2012 6:57 am

Thanks, I now feel more confident about using the good old ej20 engines. Seems like the ej204 being a phase II engine may not be an straight forward swap. What is the octane requirement of this engine? How hard is it to detune the ECU to work with a lower octane fuel? and what are the negative effects of using lower octane gas? (We have 91-98 RON fuel) though I have seen several legacy B4 TS-R with this engine on kenyan roads. I would have loved to see what kind of MPG can be achieved in a much lighter car that zips from 0-60 in 6.3 sec without turbo!

evolutionmovement · Post by **evolutionmovement** » Sun Jan 01, 2012 5:05 pm

From what I read when looking into the EJ204, it needs 97 (RON, I believe). The car I designed is meant to be a high performance car that's dirt to cheap to run and easy to maintain, so I want something that runs on the cheapest gas we have.

Stupidly, the one thing I didn't mention is that you can get an OBD 2 engine and just use the short block to bolt all your OBD 1 stuff to. If the heads on the OBD 2 match your OBD 1 intake manifold, you could just swap out the long block with the heads and use your sensors, exhaust, and intake system with the new block. I did this with a turbo block to run it as a normally aspirated and it took me an afternoon working alone (I even moved the engine myself). If the intake doesn't match, you should be able to swap the heads without a problem. Even different displacement heads can work as people swap 2.5 liter heads onto 2.2 turbos to get DOHCs. However, I can't recall which gaskets you use in that case. You should be able to find it here with a search.

carlito · Post by **carlito** » Fri Jan 13, 2012 1:46 pm

Hi, thanks for all the advice so far. It has been very useful to me.I have
been doing thorough research and also looking around engine shops
for a compatible engine.

Surprisingly the 1st generation engines cost
just as much if not more than second generation engines (something to
do with how hard they are to find?). The other thing is they rarely sell
together with ECU and Harness so I figured I may as well buy a newer
second Gen engine and use my manifold, sensors and heads like you suggested.
Turns out the EJ204 is too rich for my old car so I have zeroed in on three DOHC
engines all NA.

1. 1992 EJ20 from a Legacy wagon, chassis: BF5 that makes 150hp@6800 rpm and
torque 17.5kg · m (171.6N · m) / 5200rpm. Compression ratio is 9.7 and
requires regular petrol. Gas mileage 24-28 mpg. (This engine is most similar to my
blown engine)

3. 1996 EJ20 from a Legacy TSR chassis:BD5, that makes 155hp@6400 rpm but torque
is up at 19.0kg · m (186N · m) / 4800rpm. Compression ratio is 9.7 and and works
with regular petrol. Gas mileage is 28 mpg.

3. 1999 Ej20 from a Legacy B4 sedan, RS chassis: GF BE5, that makes 155hp@6400
but torque is up at 20.0kg · m (196.1N · m) / 3200rpm. Compression ratio
is 10.8 and requires premium petrol. Gas mileage is 30 Mpg.

Now since these engines don't come with ECU or Wiring harness I have to
make them work with my ECU. The last engine would be the best choice
because it has more torque sooner as well as better mpg
however the compression ratio is higher (10.8 vs 9.7) than my old
engine. Can this work safely with my heads?. The other thing is the clutch
which is the pull-type vs my current push-type. Unless its a simple and inexpensive
job to get this engine to work, I think I will settle with the second engine.

So what I want to know is:

1. Can I use the higher compression motor short block with my heads and manifold?
and still get about the same good mpg and power?
2. What modifications will be needed other than clutch, flywheel and pressure plate for
the pull-type clutch setup to work?
3. I hear beyond '96 the transmission linkage changed i suppose this won’t affect the engine swap?
4. Will I need to buy some kind of fuel and timing controller or will the old ecu with old sensors and
Manifold do?
5. If I decide to go with a Gen 1 engine that is newer than my stock engine will it work if I simply drop
It into the bay and connect all sensors or will i need to still use my sensors, such as IAC, TPS, MAF,
Igniter etc?
6. One last newbie question

Will an engine pulled from an auto car work with my manual transmission?
What will I need to change other than flywheel?

Any other thing I need to consider?

Will appreciate any advice

beatersubi · Post by **beatersubi** » Sat Jan 14, 2012 2:51 am

It would be best to get the engine that most closely resembles yours. Your ECU will be the biggest factor in fuel mileage.
Your flywheel and clutch assembly will fit the replacement engine.

entirelyturbo · Post by **entirelyturbo** » Sat Jan 14, 2012 3:53 pm

I agree with beatersubi that you'll encounter the least amount of headaches by swapping in the first engine that is most similar to your old one.

But the high-comp BE5 engine could be made to work as well. I can't say what compression ratio you'd end up with by putting your old heads on that engine, but I doubt it would increase any, so you should theoretically be fine with your old heads, sensors, ECU, and wiring if you continue to use premium gasoline.

If that engine is JDM, I strongly suggest you be VERY thorough about finding out all you can about it before you buy it. Japanese cars are required to have their engines fully rebuilt at 60,000km or face heavy tax penalties... so, there is little incentive for car owners in Japan to do proper maintenance on their cars. I would get as much information on the condition of the engine as possible (detailed service history, pictures of the dipstick like Steve suggested, maybe even a compression test, etc.), and the less info the seller is willing to give you, the more apprehensive I would be about buying it.

Fitting a Phase II engine into a Phase I car shouldn't be an issue... plenty have done it before. However, why do you think that the BE5 engine uses a pull-style clutch? To the best of my knowledge, all N/A Subarus worldwide use push-style clutches.

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kimokalihi · Post by **kimokalihi** » Sat Jan 14, 2012 4:02 pm

Go with the one that matches your engine. You don't want to be spending the extra $30+ cents per gallon ($3.60+) tank after tank after tank for premium fuel.

carlito · Post by **carlito** » Sat Aug 18, 2012 11:08 am

Thanks guys for all the advice. I finally got an engine which is closest to my earlier motor. However i have no way of knowing which year it is. how can I tell which year?. Its an EJ20 DOHC engine with coil on plug configuration rather than coil pack setup. The only difference I have noted is that it has gray injectors as opposed to the red ones in my earlier engine.

I also have a constantly flashing CEL light that refuses to go away. the code looks like code 32 which is oxygen sensor fault. I have the old sensor but the wire is cut. A new one is bloody expensive from the local stealership, is it possible to join the wires? my mech says its not possible to solder the wires together.

The engine is very responsive and pulls hard but there is a slight surging and delayed throttle response at times which i attribute to the oxygen sensor. I couldnt find flushing oil so I used 15w40 shell helix hx5 which has extra detergents its an API SN so am assuming its got enough zddp for our flat tappet style engines. I plan to change the oil again in a weeks time. The only oils i have found in the market that I suspect have enough zinc levels for our engines are:

Shell Helix Hx5 Conventional 15w40 API SL
Castrol GTX Conventional 20w50 API SH
Valvoline Vr1 5w50 Synthetic API SL

My manual calls for 10w30 or 10w40. The temperatures here range from high 70s to low 50s all year round. so am not sure which one to use for best engine protection. But otherwise am happy with the new motor. so guys please help me identify the engine,join the oxygen sensor wires and advice on the best engine oil for my application.

evolutionmovement · Post by **evolutionmovement** » Sat Aug 18, 2012 2:31 pm

Unless there's a different standard for O2 sensors, you can use any sensor with the same number of wires. You can definitely join the wires up. in the US, they sell universal kits (usually made by Bosch) where you buy by the number of wires. The kits come with a connector you use to splice the new O2 sensor to your original wires so that you can use the OEM plug to connect to your harness. The kit uses compression barrels to splice the wires together. I have used these several times and they definitely work and are about half the price of OEM O2's. But that might be more information than you need if your O2 is known to be good, just splice it/solder it back in, get some heat shrink to weatherproof it, and you should be good.

I also respliced an old O2 on my Mazda 3 after I replaced it in error (my car was some kind of odd ball that didn't match the book, having 2 sensors which were supposed to both be narrowbands on the federal cars vs. the 3 with a wideband that the California cars had. I had a wideband and 2 sensors and the wideband only had 4 wires like the narrows, etc. It got all Italian car on me for a bit and I had to consult both Mazda and the O2 manufacturer to sort it out). Sorry to have you read all that junk, but my point is that after resplicing the good sensor, it worked fine.

Post by **Legacy777** » Sun Aug 19, 2012 9:19 pm

The 15w40 is probably the closest thing to 10w30. You really don't want a lot of zddp in the oil as it can damage the catalytic converter. As long as the oil is made for modern gasoline engines, you should be ok.

carlito · Post by **carlito** » Tue Aug 21, 2012 7:41 am

Thanks guys, any idea how i can tell what year the engine was manufactured? I dont have engine codes or chassis number of car it came from. All I know is its a 1989-1994 based on the coil on plug setup. I need to know incase I need to replace the ecu/tcu.

Post by **Legacy777** » Tue Aug 21, 2012 5:26 pm

Any ECU from that era car should be ok.

Is there any markings or stamped info on the engine?

carlito · Post by **carlito** » Thu Aug 23, 2012 3:43 am

All I see is ”EJ20” as well as the engine serial number. Is there a site I can cross reference vin code with this engine serial number?

Post by **Legacy777** » Fri Aug 24, 2012 6:08 pm

I'm not aware of a site that will give you that information, but that doesn't mean there isn't one out there.

carlito · Post by **carlito** » Sat Aug 25, 2012 12:24 pm

Ok thanks, I have just read something online to the effect that the year is embossed at the back of the oil cap, dont know how true that is. But mine reads 90 so am assuming MY of engine is 1990.

Post by **Legacy777** » Mon Aug 27, 2012 5:19 pm

I'll have to check the oil cap on mine and see what it says.

Thanks for sharing.

carlito · Post by **carlito** » Mon Aug 27, 2012 9:57 pm

My O2 sensor has one wire and it looks like steel. Mech insists soldering wont work. I may have to import the bosch sensor and kit because its difficult to find such items as heat shrink tubes here, dont know where to look. Another item I cant find is maf cleaner. My car still hesitates even with the new engine but yesterday I got code 23 which is maf fault error.My maf is dirty and I think cleaning it may finally solve this mysterious stumble once and for all. Could you kindly point me to a reliable online source where I can purchase this items and have them shipped to me?

evolutionmovement wrote:Unless there's a different standard for O2 sensors, you can use any sensor with the same number of wires. You can definitely join the wires up. in the US, they sell universal kits (usually made by Bosch) where you buy by the number of wires. The kits come with a connector you use to splice the new O2 sensor to your original wires so that you can use the OEM plug to connect to your harness. The kit uses compression barrels to splice the wires together. I have used these several times and they definitely work and are about half the price of OEM O2's. But that might be more information than you need if your O2 is known to be good, just splice it/solder it back in, get some heat shrink to weatherproof it, and you should be good.

I also respliced an old O2 on my Mazda 3 after I replaced it in error (my car was some kind of odd ball that didn't match the book, having 2 sensors which were supposed to both be narrowbands on the federal cars vs. the 3 with a wideband that the California cars had. I had a wideband and 2 sensors and the wideband only had 4 wires like the narrows, etc. It got all Italian car on me for a bit and I had to consult both Mazda and the O2 manufacturer to sort it out). Sorry to have you read all that junk, but my point is that after resplicing the good sensor, it worked fine.

evolutionmovement · Post by **evolutionmovement** » Tue Aug 28, 2012 12:02 am

Ah, that does sound like a different kind of O2 sensor. Not sure a Bosch kit would work. We used to have 1-wire sensors, but not for a long time. I can't recall the last time I saw one. I'm guessing the steel around it is some kind of shield, but I can't say what would happen if you try splicing it. IMO, the principle behind an O2 sensor is the same and physics doesn't recognize regional preferences, so it SHOULD work to splice any O2 sensor in as long as the threads are the same (which they may be). A narrowband sensor should be the same no matter the language of the robot that screwed it in, BUT I am guessing and stranger things have happened (my grandmother saw it rain frogs when she was a kid).

As for the cleaner, people have used electronic and brake cleaner before. Whether this is a great idea or not, I can't say. People have done a lot of things. Almost any US automotive site and Amazon have it (amazon has nearly everything). I don't know how that works internationally, though (amazon does have some other country specific sites, like uk and au).

carlito · Post by **carlito** » Sun Sep 09, 2012 9:17 am

Thanks, Amazon don't ship the o2 sensor to where I am. Still looking.

evolutionmovement · Post by **evolutionmovement** » Sun Sep 09, 2012 1:53 pm

That sucks, I thought Amazon might be completely world wide since I seem to have sold some books in Asia, the Middle East, and Tunisia (though I'm sure I'll never see any royalties from them).

carlito · Post by **carlito** » Sun Sep 09, 2012 11:14 pm

Yeah I think I have bought a few books on amazon some years ago. Maybe some automotive products are restricted. I know for instance I cant ship in petroleum products such as engine oil unless I have a special trade licence. Will look for another source.

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