19 replies to this topic

[bgd73]

I decided to change the firing order of my subaru with a sawz-all and $99 welder have a look (hopefully picture is below here) Just what I was after

[GeneralDisorder]

I fail to see the reasoning behind this. You say your engine doesn't run smooth and you can feel it in the struts??!?

Either you are delusional, or your engine probably has a bad main bearing.

All the subaru engines I've had that were in decent condtion ran butter smooth when properly tuned (usually with a weber). I've got one in my brat that has a slight bump to it at idle - previous owner neglected to change the oil pump, so now I get to rebuild it. In fact they usually run so smooth there is little indication they are about to throw a rod till around a mile before it happens.

GD

[bratsrus1]

Hey 73 This is Jerry, if you do that to the engine it will shake like a Harley, unbalance. Thats why subaru set up there engines the way they do smooth. Thanks Jerry

[GeneralDisorder]

Yeah - he's right. Now that I think about it - the crankshaft counterbalance wieghts would have to be redesigned to accomidate the new firing order. It would probably shake so violently it would rip itself apart in no time.

GD

[JonOfScio]

+1 for GD. The camshafts aren't ground to allow the firing order in that order.

If you were to send your camshafts away to be rewelded and ground (alot more than just a simple delta regrind...) or had some manufactured, you could get it to work. BUT - like mentioned, your crankshaft has counterweights which allow it to be more balanced than other types of engines.

Even though a (an example engine) F22 Honda Accord motor has a really well designed internals in a motor (run-out, clearances, tolerances, bearings, couterweights, ect.) it is not a horizontaly firing motor like ours, and so therefor they require a harmonic balancer.

Our motors (especially the newer EJ motors where it is easier) you can get lighterweight crank pulleys because they do not depend on a dampening pulley (fluidamper, ect. also similar to V8's)

If you wanted this to work, you would really need new camshafts, and either rebalancing the crank to accept the new firing order, AND/OR a dampening style crank pulley (more mass=more reciprocating weight, less efficient means of power to the ground... thus why they make lightweight pulleys for newer subarus.)

So basically, you would have a horribly unbalanced motor, similar or worse to inlines (did I make the point in that our motors are WAY better in balance?) and you may or may not lose efficiency, overall power output, engine longevity, ect. ect.

But hey, say you did do the work and got it to run right, I could be wrong about the previously mentioned problems... in which case, rock on. different is good, but don't forget about the possible theoretical issues at hand.

[torxxx]

I agree.. if it aint broke, dont go tryin to fix it. lol
subaru engines are the smoothest runnin engines out there due to the flat H configuration. The shock on the connecting rods transfers over to the next firing cylinder, instead of going straight into the bottom of the crank like on a Inline, or V configuration engine

[4x4_Welder]

Couple of points- First off, doing that would set up a resonance in the crank that no balancer would be able to get out. Next, these engine don't have a balancer because they have a very short crank, and in their current configuration the accesory belt or timing belts can absorb the resonance generated. Most v-8 and I-6 engines are counterbalanced, I have a Ford 300-6 and a 390v8 sitting in my garage with massive counterweights on the crank. Neither of those engines uses an offset balance cancellation means, IE both have an overall neutral balance without external counterweights. They do use dampers since the cranks are long enough to set up a natural resonance, without those dampers they would eventually crack the crank from this resonance.
IIRC, the Subaru engines use a cast crank as well, which can tolerate far more resonance than a forged crank, and actually is prefered in some high performance applications due to it's ability to flex and return to shape without damage more readily than a harder forged crank.

[bgd73]

All your points are quite logical. The harley one is kinda funny. A 2 cylinder wobble is a 360degree fire (missing 180 balances like all other engines bellcranking- 4 cyl and up) The best design for that crappy harley is also flat , even then it still sucks. 4 cylinders buffer that at 180. I simply saw the battle of two forces in any engine that effect smoothness. The physical crank and pistons, and when it fires. An example (true story) is a 60 degree large v12 diesel (about as high as compression can go) losing 2 cylinder on one side. A mechanic confidently to help the time constrained trucker out temporarily found the firing order and shut down two more cylinders on the other side in balanced strategic locations. The engine purred like a kitten (bad analogy for a diesel I know) with a perfectly runnable loss of about 30%. 180 flat-four is exactly correct balance for a four cylinder and the four strokes 720 degree cycle, of course it can't lose a cylinder, like a big engine with more. The picture I drew in fun is a trick on your mind when it comes to balance. Every post above except the one mentioning resonance has forgot an important balance in every engine unmeasurable : The Fire Stroke. Even then the resonance theory is forgetting that one. The fire in crazy drawing is more balanced than the 180 degree same bank firing the subaru is currently running.Each bank gets a fire at 360 in a front to back motion (opposite bank) not the two on one side then the two on the other to start over again like the current boxer.I think it would run. I would love to know.Even the crank is lighter, tighter. The only oddity I could think of is maybe offsetting shared journal for crank advance/direction. Not exactly insane like a rotary.

[85Sub4WD]

I fail to see most of the points you are trying to make - look at your crankshaft alone - ALL of you mass is moving in the same left-right-left-right fashion - that WILL create SERIOUS vibration problems - its simply the law of inertia, and there is nothing more to it - the smoothness of your engine is dermined more by the movement of the masses inside it than the actual combustion cycle itself - if you do some basic research on internal combustion engine design, or you start to work out force diagrams for the engine, you will see exactally what we are talking about

one of the things I think you fail to realize, is that one of the beautiful things about flat fours, is that they are ALREADY balanced - regardless of scale of the engine, a flat-4 is one of the few inhereltly stable engine designs - in fact, that is why it is consitered to be so advantageous over I4's, which are not inherently balanced - strait 6 engines, and V-12 engines are also naturally balanced, but for different reasons

[Uberoo]

so what would changing the firing order accomplish?

[GeneralDisorder]

He's under the mistaken impression that it will make the engine run smoother using VW fireing order... thing is I've never seen a VW flat four run as smooth as a Subaru flat 4 in stock form.

GD

[bgd73]

I don't even have a point. I did find EA82 had 3 main bearings. I have a wordless problem, and that may have fit what I was non-seriously pursuing for an answer. I am going to admit that this is my last ea82 :-\ . I am seriously saddened.10 years and about 70k on old subarus that shouldn't have made it. There is an evolution I need to step up to. I found a way to make it good for all occasions and seemed to find it's limitation with frustration.The reliability for its lightweight purpose has been great, I had no idea I shouldn't have done anything to gain more than I was supposed to (I don't even have turbo and what I did to get a little more out of it was quite humble). So. I want an ej20 in my old loyale , or step away from the whole generation. Maybe I shouldn't have learned as much as I did about it , just enough to find an embarrasing dead end.Live and Learn.Now onto those 5 main bearings....

[GeneralDisorder]

3 mains is not a problem - the reason Subaru went to 5 is to support higher power output. Perhaps you have not experienced a properly tuned, well maintained EA series engine. They do run quite smooth. A worn main will definately cause an imbalance - I have worn mains on my Brat and it has a permanent imbalance at idle.

GD

[bgd73]

Uh oh. Your enlightening me. I could do main bearings. I am willing to bet your guess is correct.Slap some new federal moguls in there and call it good. A balanced engine would do something bewildering from worn mains. I can only compare to v8's (what I used to run) and when a bearing was worn there, it was quite bluntly known. out loud.I can't seem to admit I am attached to my old subaru. Even mechanics I know would say "give it up". USMB has helped keep me going.
Donation from me soon, the manual in pdf format was priceless...

[GeneralDisorder]

Well - mains are cheap enough, but you'll have to split the case to do them... and it's a slippery slope let me tell you. Once you have it torn down, you'll say - gee I should do the rods, and install new chrome rings, and a valve job - mill the heads - replace every gasket in the engine. Oh yeah - it's a $500 job in parts.

I'm sure it would be worth it - you'll have a real nice engine on your hands. Could get some nice Delta cams for it, and milling the heads will up the compression just a bit plus compensate for the ground cams. 100 HP is not unatainable at all.

I'm not sure what a complete EJ22 swap would cost, but a decent engine will probably run about $300, and then you need the adaptor and flywheel - new clutch setup, etc. It's probably close to a wash, but the EJ22 gives you a bit more power. A lot more wiring involved.

GD

[85Sub4WD]

if you have a pull-a-part nearby, you can get a used engine pretty cheap - the one in Charlotte, NC is around $140 for a 4-banger - regardless of make/model - and the EA82 is VERY light too - you may even find a rusted-out parts car
if yours is a SPFI car, then any SPFI engine will work like stock - carb engines will work too, but they have a slightly different compression ratio, and all I've seen redline at 6k (87+ may redline at 6500)
if yours is a carb, the SPFI block will be a minor upgrade
be careful that you keep track of all the vacuum lines - they can cause issues if not connected properly

[SOOBOUTLAW]

I decided to change the firing order of my subaru with a sawz-all and $99 welder have a look (hopefully picture is below here) Just what I was after

You were gonna do THAT with a sawzall and a 99 dollar welder!!??:-\

[bgd73]

I was getting anxious and bored and decided to doodle. Of course I would like to see how tough one of the EA82 cranks are bouncing two rods in the engineerings outer limits (I bet my sawzall doesn't do much ). I do not have intentions of rebuilding if engines needs to be split. The second go around is never as good as its first. I also believe my crankshaft or something else equally "low-level" springs into differences and comes back once and awhile. that one event has changed my mind about rebuild. I had a v8 crankshaft that wouldn't hold number one rod bearing, even tho showing balanced and clean , open oil ports. All from many miles , idly sitting back to normal and changing after heat of running; elusively, the EA82 has racked up even more, at slightly higher revves, I wonder if I should where a zoot suit and chem mask to take off the oil pan . Speaking of doodling, I made this animation for ea82 (and many others)

http://93loyale.50megs.com/firoda.html

Now all i need is someone to tell me there is an error in drawing...

[Subarian]

I'm not sure what a complete EJ22 swap would cost, but a decent engine will probably run about $300, and then you need the adaptor and flywheel - new clutch setup, etc. It's probably close to a wash, but the EJ22 gives you a bit more power. A lot more wiring involved.

GD

GD is right about one thing leading to another. I've been down that road, and it does tend to get expensive. On the other hand, I just picked up a complete 92 Legacy with 162,000 miles for $250, and the engine is going into my 86 wagon. The adaptor plate is something you can build yourself, and the flywheel can be modified with a dremel or a round file. The EJ clutch is not needed, as the EA82 d/r 5 speed stays (mine's getting a turbo or XT clutch) and you can do the wiring. So it can actually be a lot less expensive to go the EJ22 route, and you get considerably more power.

[bgd73]

I really like the idea of swapping stuff. I had a chevelle that took a straight 6, v6, and many v8's (small block and big) but it was factory intendable. Each Subaru's longevity is to be balanced out with the frustration of proprietary (it is quite precise indeed). I found an impreza with hubcaps, saggin in the back, white with black trim and high miles.... just like when I found my first loyale same colors strting to rust. For same price when Loyale was the impreza's age now (with the bigger engine and 4wd...). I will not be swapping engine's unless I could make it a hobby.I would If I could, but I can't...:cool:
Where are some pics of finished Loyale Gl Dl swaps? I saw the flat-6 in the yellow wagon from here (impressive).