Fit an Subaru EJ20 into a Midlana

Which drivetrain to choose, so many choices, 4-cyl? 6-cyl? NA? Turbo?
dpkilty
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Fit an Subaru EJ20 into a Midlana

Postby dpkilty » 11 Feb 2014, 10:35

So I received my copy of the book a couple days ago. First off:
Kurt, great job on the book.

Secondly:
I was only giving it a quick glance over here and there at the time, but I noticed that there is a whole section talking about how an EJ will not work in the current configuration of the Midlana. This left me a little sad. But fear not, I am a fairly determined person when it comes to this kind of stuff. So I have been doing a little research here and there in my free time at work and found that there is a guy building a car9 chassis with an EJ motor. His wheelbase is 98” IIRC. I will have to double check but IIRC that is 5” longer than the Midlana chassis right? I know it’s in the book, but I don’t have the book in front of me right now.
So I guess I will start this thread as a general discussion about adapting the Midlana to accept an EJ motor.
Questions I have right now…

Where is the best place to add the 5”?
I am assuming just behind the seats in front of where the motor is supposed to go.

How will this affect chassis rigidity?
I do plan on drawing the chassis up in Solidworks so I can analyze it there, just curious what your guy’s thoughts are.

Will this alter the suspension in any way?
I will dig more into the book and see where suspension points are, but right now, I am going to assume it’s not going to bother it too much, if any.

I am still early in the planning stages of all this, but I am curious to see what your ideas are. Maybe you can shed light on a path to go down that I am not seeing…

I know the bodywork will change in the rear along with a slew of other things. But hey, figuring that out is half the fun right? ;)

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Re: Fit an Subaru EJ20 into a Midlana

Postby bgkast » 11 Feb 2014, 11:44

You may or may not need to add to the wheelbase length, depending on how long the subi engine is from the crank pulley (or other farthest forward part of the engine) to the axle line. Compare this length plus a few inches for access to the distance in the plans from the rear axle line to the back of the rear fuel tank cross tube (where the roll hoop mounts) and see if it will fit, lengthen the frame between the hoop and the rear axle as necessary. The subi transmission will stick out the back, making styling different, and interfering with the book rear suspension subframe. Take a look at the last few posts in my build to see how I modified the subframe to allow my exhaust to pass a similar conflict.

Unless you are extending the wheelbase by a foot I wouldn't be concerned about chassis stiffness. The suspension geometry should also not be impacted by making the wheelbase longer.
Last edited by bgkast on 11 Feb 2014, 12:01, edited 1 time in total.

dpkilty
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Re: Fit an Subaru EJ20 into a Midlana

Postby dpkilty » 11 Feb 2014, 11:52

I can shorten the transmission up a bit by removing the center diff which isn't needed. Adding an OEM spool that will make it FWD and a block off plate. The 818's do this. I will still run into the same issue but hopefully it helps a little.

I have been watching your build log, its good stuff.

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Re: Fit an Subaru EJ20 into a Midlana

Postby bgkast » 13 Feb 2014, 10:35

Here are some subi engine and transmission dimensions that I found on this very site!

viewtopic.php?f=17&t=3&start=180

Assuming those dimensions are good, and using 2" of clearance in front of the engine it looks like you would need to lengthen the car about 3.5" behind the main hoop.

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Re: Fit an Subaru EJ20 into a Midlana

Postby b33fy » 13 Feb 2014, 15:29

There are easier options, I built and ran a scooby engined v-storm, cut a long story short if you can get over the issues highlighted here all well and good, though it doesn't get any easier. As mentioned high centre of gravity, long long over hang on the gearbox and high under bonnet temps to content with. Turbo charger packaging is also a pain because of the flat 4 layout, leaving it in the origianl postion may interfere with the chassis, moving it creates other problems. Cooling these engines is also a major issue in a mid mounted config. and you'll be lucky to do anything other than change the spark plugs without taking the engine out.

The rear suspension will probably need to be built round the gearbox and be removable to facilitate a clutch change. and to get the engine out the whole back end will have to be dismantled, a days job on the storm to remove engine and box. To do the cam belt the fuel tank would need to be removable and it could be done from underneath (I did it once) though another days job and mistakes can easily be made.

Other than that its the perfect setup :D

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Re: Fit an Subaru EJ20 into a Midlana

Postby bgkast » 13 Feb 2014, 16:26

V-strom? That's a new one to me...I've only ever herd of the bike. Looks cool, but I agree access looks difficult!

Image
Image

Access might be better in the Midlana Chassis!

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Re: Fit an Subaru EJ20 into a Midlana

Postby dpkilty » 13 Feb 2014, 20:29

b33fy wrote:There are easier options, I built and ran a scooby engined v-storm, cut a long story short if you can get over the issues highlighted here all well and good, though it doesn't get any easier. As mentioned high centre of gravity, long long over hang on the gearbox and high under bonnet temps to content with. Turbo charger packaging is also a pain because of the flat 4 layout, leaving it in the origianl postion may interfere with the chassis, moving it creates other problems. Cooling these engines is also a major issue in a mid mounted config. and you'll be lucky to do anything other than change the spark plugs without taking the engine out.

The rear suspension will probably need to be built round the gearbox and be removable to facilitate a clutch change. and to get the engine out the whole back end will have to be dismantled, a days job on the storm to remove engine and box. To do the cam belt the fuel tank would need to be removable and it could be done from underneath (I did it once) though another days job and mistakes can easily be made.

Other than that its the perfect setup :D


:lol:

Under bonnet temps could be dealt with vents of some sort on the rear of the car. That and some clever use of thermal barriers (read ceramic coatings) and heat shields. All of which I had thought about doing anyway. Cooling was an issue I knew I would have to contend with, but was hoping the radiator could handle the task.

The turbo charger packaging is still up in the air for me. I could go stock location to keep things simple, I could flip the header around 180* and run it in front of the motor (not sure if I would gain anything useful doing that...) or I could run a low mount setup out the front similar to those being used on some of the new BRZ/FRS turbo kits... Again, not sure how much I would gain going that route, if the pros would outweigh the cons. Yeah it would help quicken the spool up, but unless the turbo is above the oil sump I will need an electric scavenging pump to keep the turbo cool.

Having worked on Subies for about 3 years I have realized that no matter what you are doing its arguably easier to pull the motor anyway...
Clutch change = pull the motor > loosening the motor mounts tilting it forward, disconnect the driveshaft, move the transmission back and have about 1/2 the room you really need...
Timing Belt = pull motor > removing radiator and fighting alternator, power steering pump, ac condenser & pump and still not having very much room to work
Replace turbo = this one can be done easily with the motor in the car... except for the dreaded oil drain tube...
Turbo Inlet = remove the intake manifold which takes a normal person 2-3 hours

Subaru's are a fun platform, but they just aren't easy to work on. I will definitely make the rear cradle removable.

The more I read the book and research the more I am going to have to make alterations to the midlana plans to make this work. Which is fine with me, I am not afraid to make changes I just haven't made myself familiar enough with the design yet to know whats really important and what can be changed easily.

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Re: Fit an Subaru EJ20 into a Midlana

Postby bgkast » 13 Feb 2014, 20:33

Unless I am missing something I don't see why under hood temperatures or cooling would be any different than with a transverse FWD engine.

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Re: Fit an Subaru EJ20 into a Midlana

Postby dpkilty » 13 Feb 2014, 20:42

bgkast wrote:Image

This helps a lot. Gives me a few ideas...

They are still running a top mount intercooler, which I will not be. I will run a front mount vertically on the side using the vents in front of the rear wheels.
Hopefully I can keep a little weight out of the motor by using one of the plastic intakes instead of the aluminium ones. Not only are they lighter, but the flow a tiny bit better as well.
Not sure I would tie the pitch mount (bar from top of the roll cage to the transmission) to the roll bar up top. Might go back over the transmission or triangulate it somehow...

Thanks for posting that.

Cooling is always an issue on a turbo platform. No matter if its a FWD Honda or Ford or whatever.

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Re: Fit an Subaru EJ20 into a Midlana

Postby b33fy » 14 Feb 2014, 13:39

dpkilty wrote:
:lol:

Under bonnet temps could be dealt with....


You're more of an expert than I am with these engines so apologies if I'm not making sense or saying nothing new :)

Here's mine on a run with its dopelganger.

Image

Another in its natural habitat broken by the side of the road, France on this occasion.

Image

Cooling was a particular issue with the stom because of the twin radiator arrangement at the back. Under bonnet temps aren't helped by the twin headers and turbo positioning which was up higher than the usual position. which was tight against no 3 cylinder, which coincidentaly is the piston/cylinder most likely to fail. an inline 4's have the turbo and exhaust towards the back of the engine so is easier to manage the heat.

Apologies if you have thought this through,.. a couple of pointers if you haven't. For me the header pipe across the front of the engine preheated the fuel tank as it was too close to the tank not protected etc to the extend where it pressurised the tank and I got spillage as the tip valves etc didn't cope with the build up.

To ensure the thermostat functions properly loop a pipe to the heater inlet and return pipes, this ensures that hot water flows across the cold side of the thermostat to make it work. I was mis informed and it caused me no end of problems

The gearbox is rod operated and doesn't lend itself to be converted to cable, if you haven't already got a solution and don't want to pay silly money for a bespoke solution post up and I'll dig out my approach to the problem which worked well whilst I had the car

All the best with it, they do sound good and pull like a train, sadly for me it didn't work out.


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