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EJ made to run like a big 2 cylinder, lots of lowend Tork Discussion


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38 replies to this topic

#26 Gloyale

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Posted 22 April 2012 - 06:47 PM

Hmm, I hadn't thought of it that way. The way I was thinking of it was like this.
When 1 is at TDC compression, 2 is at TDC exhaust.
At the same time, 3 is at BDC intake. and 4 is at BDC after firing.

Turning the pass cam 180 would cause it to run as the 2 cyl. But, now you have me doubting that. I can't visualize the camshaft lobes in my head very well. Next time I'm in the garage I have an engine with the timing covers off that needs a rebuild or something. Still has compression on all cyls though, so maybe I'll mess around with that and see if it's even possible to get the compression at the same time on opposing cylinders.



i think you'll end up with intake valves opening at BDC instead of TDC at least on that one side.

#27 987687

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Posted 22 April 2012 - 06:53 PM

i think you'll end up with intake valves opening at BDC instead of TDC at least on that one side.


Yea, I think you're right on that one.

#28 Gloyale

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Posted 22 April 2012 - 07:18 PM

It could work possibly if you ran a drivers side cam drivers side cam on the passenger side, 90 degrees shifted.

Of course, there's not really any way to do that without some adaptations.

#29 1 Lucky Texan

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Posted 22 May 2012 - 01:32 PM

anyone come up with a way to make the cams 'mirror images' of each other?

#30 Gloyale

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Posted 25 May 2012 - 11:00 AM

front fire and then back fire , not each bank.



12 fire, begin power stroke down ----- 34 begin compression

34 fire, begin power stroke down ----- 12 begin exhaust

12 begin intake ----- 34 begin exhaust

34 begin intake ----- 12 begin compression
repeat



This is wrong.

firing order is

1-3-2-4

1 and 3 are on the passenger side, 2-4 on the drivers side.


one bank fires, then the other.

#31 1 Lucky Texan

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Posted 25 May 2012 - 11:28 AM

This is wrong.

firing order is

1-3-2-4

1 and 3 are on the passenger side, 2-4 on the drivers side.


one bank fires, then the other.


it isn't clear from the OP what was intended so, yeah, maybe you could make it work that way too. I just went to the first arrangement that seemed like adjusting a cam would let a couple of cylinders be at compression at the same time. But, now, it seems either way requires custom cam(s).

Edited by 1 Lucky Texan, 25 May 2012 - 11:49 AM.


#32 Fairtax4me

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Posted 29 May 2012 - 09:55 PM

Lets fix that...
The way the crank works, you wanna fire 1&2 at the same time, 3&4 at the same time, with a big pause in between fires for the engine to exhaust/intake. Gonna sound like a big lawn mower. (as if Sube engines didn't already) :lol:

This can easily be done with the stock wasted spark coil pack.

Cams are the basically the same, IIRC, except for the snout on the passenger cam sticks out of the end of the head, so you can just flip the drivers side cam to make it open/close valves together rather than in the normal sequence. Turn it 180. 360 degrees, (thats 1 whole turn) just puts it right back where it was in the first place. :horse: Prollem is, I think you'd end up with BANG BANG nothing nothing, when what you need is BANG nothing BANG nothing. Custom cams are gonna be a definite yes. Talk to Delta? Need someone who has the know how to either modify the existing cams, or design a custom set.

Ignition timing is done by the crank, injector timing is driven off the drivers cam sprocket. Some creative placement of weld beads on the back of the sprocket could possibly be used to trick the ECU into spraying when you need it to. I think this could be set up with a decent EM system. Just set it up to run a 2 cylinder engine, but use the "spray 2 injectors at the same time" idea.

Edited by Fairtax4me, 29 May 2012 - 10:11 PM.
Got muh numberz mixed up. This countin' is HARD!!!


#33 el_freddo

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Posted 30 May 2012 - 02:18 AM

Why hasn't anyone tried spinning the passenger's cam 180 deg and replacing the belt to see what happens? I'm 99% sure that the EJ subarus are still a batch fire setup so the EFI system should be able to do it, the knock sensor might have a hissy fit though.

I don't think custom cams are going to change much, you're going to end up with 1&2 firing then 3&4 firing one after the other, then the exhausting, sucking, squeezing without any power.

I can see how the V8s can get away with it, they're essentially running as a 4 cylinder with 4 bang events that can be spread out enough to match the 4th event in the cycle evenly to the 1st for a continuous spread for power strokes.

You'd probably have to look into a custom crank that would have all 4 pistons hitting TDC at the same time to achieve the double explosions at opposite ends of the cycle to make it a regular beat - there'd be one explosion per revolution, instead of the current 2 explosions per revolution.

If I've got this very wrong, flame away, I'm happy to stand corrected, but this is how my mind is thinking at the moment. It'd be a bit of fun to see what would happen, but a lot of work just for some ************s and giggles.

Cheers

Bennie

#34 ShawnW

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Posted 30 May 2012 - 06:01 PM

I don't think the cams are going to be hard to figure out, just a matter of figuring out who can make them. Its just a copy of the front lobes.

Isn't this going to shake like crazy and make the whole design of the boxer engine a moot point?

Getting the injectors to work is probably a matter of the cam and crank sprockets or maybe running a distributor with a rotor that points to both plug wires at once.

#35 1 Lucky Texan

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Posted 30 May 2012 - 11:03 PM

.

Isn't this going to shake like crazy and make the whole design of the boxer engine a moot point?


maybe not a huge amount of vibration, I suspect the crank will snap - but either way, it will be glorious all the way to the point of catastrophic failure!

#36 TheLoyale

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Posted 31 May 2012 - 07:34 PM

I read this whole thread, interesting idea for sure. I'm not gonna post any technicals as I don't want to get into thinking about it right now ;)

Would be cool to see this idea, realized. :burnout:

#37 Storydude1

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Posted 31 May 2012 - 08:51 PM

Making a subaru Boxer into a Big Bang motor is going to be difficult. Even more so with EFI.

#38 maozebong

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Posted 31 May 2012 - 11:34 PM

well, if you ditched the fuel injection for a carb, and had the cams made, it should work fine. the fact that it's wasted spark makes it all possible. efi would be either expensive or you depending on the impedance of the the ej injectors, you would have to splice 1 and 2 to fire together. (same with 3 and 4)

if they are high impedance injectors (usually 10-14 ohms) you can easily do this. splicing means two injectors have to run off one injector driver in the ecu. two lower impedance injectors that equal out the normal impedance wouldnt fry the driver, or not operate properly, with too much impedance. either that or you drop $1k on a REAL standalone ecu, not MS.

carburetion is the easy way out, and the cheap way. considering the fact that all big bang motors ive ever seen were in racing, where longevity isn't a concern, i wouldnt spend much on this without a pile of ej parts in my shed.

Edited by maozebong, 31 May 2012 - 11:38 PM.


#39 Scott in Bellingham

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Posted 01 June 2012 - 12:46 AM

good stuff guys I want to try this soon anyone want to help im in bellingham wa




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