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Learning how to build Lotus Seven replicas...together!
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PostPosted: Sun Jul 22, 2007 10:16 am 
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You could always build a middy like the Blast.

Design your bell housing adapter as thin as possible. Add the bell adapter thickness to the distance from where the Subie crank flange is to where the Toyota crank flange would need to be relative to the Toyota input shaft. The crank adapter uses the Subie flywheel bolts to attach it to the Subie crank. The Toyota flywheel bolts are threaded into the adapter. If the Toyota pilot bearing presses into the Toyota crank and not the Toyota flywheel, machine the crank adapter to accept the pilot bearing.

I don't see a practical way to mount a starter. If the Subie starter sits aft of the flywheel, the direction of rotation is opposite of the Toyota starter.

To simplify the starter issue, consider a large bellhousing transmission for a large GM engine, either the BOP or the SBC pattern T5 or Tremec. GM trucks usually have larger diameter flywheels than the cars, allowing the forward mounted starter to be further from the crank. (FYI, the T56 six speed uses a smaller bell and flywheel than a truck bell but the block bolt pattern is the same.)

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PostPosted: Sun Jul 22, 2007 11:32 am 
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Location: Sacramento, CA
I'm having a tough time visualizing how the tranny is making the engine too high. The lowest part of the tranny is higher than the oil pan, so it's not really creating more ground clearance. Or is there something that I'm missing.

Just cut up the shifter and weld it together shorter. Cut the two rods to length. Or make your own shifter, it's pretty easy for a subaru.

As far as the weight, yeah it weighs a little more, but i dunno how much more. I wanna say it's around 120 lbs. So after you make an adapter what's the weight difference going to be? 15-20 lbs? After you remove all the crap from the center diff you don't need to convert it to RWD, and remove the ring gear from the front diff the weight difference probably wouldn't be that much. If you can find some way to seal the front axle shaft outputs, you could remove the whole diff assembly, and drop even more weight.

Though if you're planning on a LOT of power, I think the subaru tranny might not be up to it.


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PostPosted: Sun Jul 22, 2007 12:58 pm 
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THAWA, you are correct, the Subie trans is higher than the stock oil pan, here's a few measurements I took just to convince myself that there is a big gain to be made by using a diffeerent trans.

With the subaru engine sitting with the oilpan on the floor the crank is 11" high

With the subaru engine in the car the crank is 20" high
With the subaru transmission in the car the drain plug is 10" high
(assumed to be the lowest point, but may not be)

With the engine in my supra the crank is 13.5" high
With the transmission in my supra the bottom of the trans is 6.5" high

I conclude from this that the subaru trans input shaft is 10" up from the bottom of the case and the toyota trans input shaft is 7" up from the bottom of the case.

Of course the subaru oil pan mounted to the toyota trans will stick way down. With the subie engine sitting on the floor on it's oil pan I had to put the toyota trans on 5" high blocks to get the input shaft to line up with the crank. Depending on how much oilpan I want sticking out the botttom of the car I will need to shorten the oil pan by a few inches.

I took a pic, but I can't get it up here right now.


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PostPosted: Sun Jul 22, 2007 11:24 pm 
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This should give a nice low CG when I cut down the sump and take out those blocks of wood :twisted:


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PostPosted: Tue Jul 24, 2007 10:41 am 
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Ah okay. I'd be careful removing too much of the oil pan. Subarus aren't good with the bottom end in stock form, and removing oil from the system doesn't sound like the best idea. It's not uncommon to spin a bearing with high g loads from oil starvation, high meaning like .9G+ in a subaru. Hell my old EJ22 spun a bearing doing donuts. I'm sure there are more factors that caused it, but the oil issue didn't help. I think if you go up about 3 inches, you're at the windage tray, so filling with oil from there is going to create drag on the crank. Though maybe it's higher. I've never measured. Maybe go with a dry sump if you want reliability.


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PostPosted: Tue Jul 24, 2007 12:03 pm 
Ha, that would help explain why I spun a bearing in my EJ22 @ an autocross on a go-kart track. I spun going into turn 5:
Image
and when I started it back up, I heard some nasty rod knock.

--JOsh


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PostPosted: Tue Jul 24, 2007 1:43 pm 
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I will try to keep the volume of oil the same by ading some kickouts or something on the sides. A dry sump would be nice, but not in the budget. The sandrail/dunebuggy guys provide all sorts of examples of cut-down/replacement oil pans for EJ's.

I'm starting to think the easiest thing to do would be to cut the "bellhousing" part off the front of a subaru trans (shouldn't be hard to find a wrecked one) and weld a plate on the back that matches the W58. It looks to me like the automatic transmissions would be abit easier to remove the front section from, but obvioulsy wouldn't provide the clutch release fork (which is pretty integral to the trans case).


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PostPosted: Wed Jul 25, 2007 12:50 am 
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I think a good baffle design would be the key.


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