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Previous Next Up Topic Engines / Subbug - Subaru Power / why modify oil pan (9602 hits)
By michael c #69 Date 2007-07-22 22:10
I'm new to this subject of subaru power what would be involved in puting one in a rail buggy for street use what trany  bus or sedan  and why do you modify oil pan probably more questions to ask but any input appreciated thanks mike
By Terry F Date 2007-07-23 08:19
The Subaru hangs down nearly four inches lower than the VW motor when bolted to the VW transaxle which reduces ground clearance dramatically. The modified oil pan from Outback Motorsports is approximately one and one half inches shorter than the OEM Subaru pan which helps reduce the chance of striking a rock or other hard object. I think Paul is going to start offering shortened oil pans and his may be a tad shorter than Outbacks...
Terry
By @Jeff GS Date 2007-07-23 11:40
In addition to what Terry said - the transaxle.  A built T1 trans should be fine for all but an all-out race car.  For sand or serious off road use you'd probably want to step up to a T2 trans, but it'll need to be gone through as well.  That's an area to discuss with your trans builder.

The EJ25 makes around 165 ft/lbs of torque, while the turbo motors make in the low 200 range on boost.

You'll also need a cooling system, EFI compatible fuel system, and ECU to control ignition and EFI.

Jeff
By Paul Moran (DBA Architect) Date 2007-07-26 03:53
I did finish my first shortened pan earlier this month.  After finding one pin hole with a leak test, it didn't leak at all after a week of abuse, err - testing, in the dunes.  I'll have to remeasure how much I took off the bottom (I modeled the cut after the pan shortened by Leading Edge). 

My challenge was the pick-up tube.  I'll have to get some brazing rods and a torch for the next one.  TIG welding on top of brazing is NOT the way to go.  But leak testing is the key - my Leading Edge shortened pan leaks like a sieve or it could be the fitting.  I discovered the EJ25 did not have an oil pan gasket on it and the manual did not mention one. I put a cork gasket on the EJ25.

Paul...
Chicago, IL
EMPI Imp 1002 ('69)/Subaru EJ20 Turbo/LinkPlus ECU
By charliew Date 2007-07-26 14:04 Edited 2007-07-26 14:08
Paul when you go to get the brazing rods see if they have silver solder, It looks pretty much like brass but is easier to work with, it seems to flow better and has a lower melting point. If they don't have it at the welding supplier you might can get it at a jeweler. In the 60's that was what we used to repair mechanical cash register parts in an emergency. It seems to be just as strong on small parts, and the way the pickup and dip stick tube look I think it's silver solder, it doesn't take near as much heat but both types have to have flux and the surface needs to be really clean. On the pickup, the best job I've done so far is to heat the tube and slip the cup off, cut the tube to length and re attach the cup, this way there's no joint with rough edges in the inside of the tube, it looks almost original. I didn't try to heat the cup to remove the support because I was afraid I would damage the screen so I just cut it and rewelded it shorter after some bending to get it to align with it's mounting hole. This type of glueing parts together is just like sweating copper together with solder except the steel will need to be a very slight just barely red, any hotter and the silver solder will bubble (boil). Practice on the old parts you removed on the first one. You can get brass rods with flux on them but you still need some extra flux to paint the surface before you start. I'm not positive but you might be able to silver solder with a propane torch, I don't know if it will get hot enough to braze though. Have fun,

Charliew
By Paul Moran (DBA Architect) Date 2007-07-26 15:06
Thanks, Charles - that makes a lot of sense. 

What did you use (propane?  Oxy-acetylene? MAP?) to heat up the tube to slip the cup off?  I've got an IR thermometer I could use to get a feel for the temp the silver soldier starts to do its thing.

Sorry for taking this thread a bit off topic.  We should probably have a topic on pan shortening itself.

As far as how much to shorten a pan - I think of it 2 ways. One is to ensure you have enough oil to keep the engine happy and the other is that there's no sense in shortening the pan any shorter than the lowest item on the engine.  You have to keep the "angle of departure" in mind also as items hanging low toward the rear of the vehicle are more critical than items hanging between the rear wheels.

Right now on the EJ25 has the stock exhaust on it, but it points forward.  So it hangs much lower than the shortened pan.  Then there are the 2 bars going back to support the rear facing radiator.  Swapping to an exhaust tucked up closer to the engine and relocating the radiator would probably cause the oil pan to become thee lowest item again. 

If you don't shorten the oil pan, a skid plate (the 97 Outback came with one) would protect the oil pan from speed bumps and bad driveways.

Paul...
Paul...
Chicago, IL
EMPI Imp 1002 ('69)/Subaru EJ20 Turbo/LinkPlus ECU
By charliew Date 2007-07-27 03:35 Edited 2007-07-27 03:43
I will try to post some pictures when I can get my son to help. My modified headers are pretty short. I am presently thinking of using a remote filter because the oem oil cooler and filter was the lowest item hanging down. I think the pan and headers are 4 5/8 below the block pan mounting surface. I agree the pan should be as deep as it can be.

I used a oxy-acetylene but in the 60's all I had at home was a propane torch. It worked on small items okay with silver solder. With the torch you need a real small tip, you can actually push the molten brass or solder around with the flame and get it to flow. Silver solder I believe is an alloy of brass and silver. When you heat the oil pickup tube to remove the cup you are mostly applying the heat to the tube so as not to damage the screen. The tube will need to be dull red going to cherry red when the brass or solder loosens and you pull the tube out. To really do a good job the metal has to be shiney clean and use plenty of flux to re braze it. Try to find some silver solder and use a propane torch and you will be amazed at what broken parts you can save or make. I use a wire wheel to shine the metal up and then some emory cloth. The only thing you won't like is cleaning the flux off after your through. Its pretty hard stuff. I don't seem to stay on topic to well.

What is the thinking about slightly raising the tranny where its mounted to the horns for more clearance? Just a thought.

Charliew
By Terry F Date 2007-08-27 05:08
Found this on youtube, it looks like the leading edge pan...

http://www.youtube.com/watch?v=fBpTlTpWDWs
By Paul Moran (DBA Architect) Date 2007-08-29 03:13
Hey Terry - As far as I know, Leading Edge is out of business.  The pan pictured is cast, isn't it?  My Leading Edge pan is just chopped at the bottom with a steal plate welded on flat. 

John Edwards (the video mentions him at the end and I'm pretty sure he's in a couple shots) is a SubBug member.  He writes for Sand Sport magazine and wrote a great article on converting an EJ to E85 fuel.

Paul...
Chicago, IL
EMPI Imp 1002 ('69)/Subaru EJ20 Turbo/LinkPlus ECU
By @Jeff GS Date 2007-08-29 11:15
Yea, that's the John Edwards pan, also sold by Pantera Specialities (which, despite the name, also sells high performance Subaru buggy engines and parts).
I talked to John about his pan, it has a cast aluminum main housing and steel bottom plate.  It's up to the builder to install any internal baffling and shorten the oil pick-up - but otherwise looks like a nice piece.
FWIW, I've read John is an expert and highly regarded machinist and engine builder.  He apparently builds custom sand buggy engines and others.

Jeff
Previous Next Up Topic Engines / Subbug - Subaru Power / why modify oil pan (9602 hits)

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