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I had always figured if I were to do a build and needed reverse, that electric reverse would be enough for me. Then I noticed how some of the overall ratios add up, and enough gear to be spirited down low turns into more revs on the highway than you'd like. Now I've ended up with a sportbike motor and have given more thought about what I may do with it...

How about putting something like an aluminum GM Powerglide, without the converter, after the bike engine? It is common practice to run them without a converter in many racing applications and should be especially streetable behind an already clutched transmission as an auxiliary. ~95lbs without the converter. ~1.76:1 first, 1:1 high would really make the rear end ratios work out well as all but highway driving could be done with it in low. And of course, reverse built in.

Drive adapter for eliminating the converter:

http://pitstopusa.com/i-5054675-winters ... lange.html

With a working clutch within the bike engine/transmission, I'd use a simple ball valve for transmission fluid control, although it likely could be set to full open, full time.

Consider the radial load on the input and output that will be created. You'd need a support bearings on each end.

A 4wd trans without the transfer case would be about as short as they get.

Efficiency would still suffer, even without the converter and the spike loads on the trans would not be absorbed as they would be by the converter.

The ratio spread is huge compared to a bike trans, so a reduction in timing and/or premium fuel may be required.

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Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

Sure, on the input side, unless it is going to be shaft driven as many do. Output? I'm picturing it installed the same way it would be in say... the traditional longitudinal V8 rear wheel drive application it's stolen from.... except a bike engine (and it's transmission) in place of the V8. So output is going to be traditional driveshaft to traditional ring and pinion out back.


A wash.... if you beat the powerglide much in dimensional length, it'll likely give up strength / commonality/ something. It can have the same short tail treatment most 4wd transmissions would have.

They take VERY little to drive, and even if at the front sprocket a BEC made 600-900 ft lbs, that's all within range of what one can handle if need be. They run in 2500-3200lb cars with V8 torque and don't flinch at full throttle shifts, even when ran without the converter cushion.

Yes, I would in no way think of doing this if it wasn't in ADDITION to the 5/6/whatever speed sequential goodness gearbox integral to the donor package that's kept in most of these builds.

Sounds reasonable. You may have a hard time finding a diff with sufficient torque capacity that has a ratio less than 2.5:1.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

I've been wondering about the same thing for my Bike Engine project.......With the exception of using a Muncie, Borge Warner, or a Saginaw......for the reverse gear

http://www.circletracksupply.com/SAGINA ... THERS.html



There compact, light weight and relatively locost:

4 speed GM transmission Rebuilt Saginaw and Hurst Shifter/Linkage - $250 (Littleton)
http://denver.craigslist.org/pts/2669037262.html

Saginaw trans. - $20 (loveland colorado)
http://fortcollins.craigslist.org/pts/2657453213.html

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Ahh; gitty up!

So what would you put on the input shaft of that three speed? you have that spline there and you could get the matching spline from an old clutch disc and weld on a flange to mate up to the output of the bike engine. Just leave the trans in high gear or use the reverse..............................

AL

I figured a drive shaft company could fabricate something for the shaft........My only reservation was if one could clutchless shift the transmission into reverse......with out having to Fred Flintstone it or having someone push me backwards to engage reverse?

I'd be interested in learning more about the Powerglide...... automatic trans and how that might work vs the saginaw.....manual.
seams there's more parts to the Powerglide, there for weight ........ Price wise they're comparable and there both used in racing applications which I like.

Racing Powerglide + oil cooler+shifter+starter+flexplate - $500 (Littleton)
http://denver.craigslist.org/pts/2610429907.html

**** 2 SPD. POWERGLIDE ****** - $250 (Aurora)
http://denver.craigslist.org/pts/2635411892.html

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Ahh; gitty up!

A Powerglide or TH350 is a common trans of choice in circle track and can be ran with an available torque converter eliminating direct drive flange http://www.circletracksupply.com/PowerGlide-DIRECT-DRIVE-FOR-AUTOMATIC-TRANSMISSIONS.html which would allow you to cut away most of the bellhousing. ..
Low 2nd thru 5th then high 3rd thru 6th might give a nice gear spread.
Rather similiar to a laycock overdrive in how it would operate with the addition of a reversing function i would think.
You wouldn't be able to hold high range until you had some shaft speed to power the pump and create apply pressure which would probably mean a bit of a harsh engagement in reverse from a dead stop too.

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"There are times when a broken tool is better than a sound one, or a twisted personality more useful than a whole one.
For instance, a whole beer bottle isn't half the weapon that half a beer bottle is ..." Randall Garrett

Yes, I could see that as an issue. I'll have to play with a test setup over the winter to see what kind of input shaft rpm produces enough pressure for apply to work, I suspect that 200-300rpm for a few seconds would be enough to engage reverse.

I was curious how quickly pressure drops after the input shaft stops. For instance, it might be possible to put the auto into neutral, get it to ~1000-1500rpm input shaft speed, clutch the bike transmission and quickly select reverse and have enough pressure still in place to have a nice smooth reverse engagement.

I've always wondered if a power steering pump could substitute for the normal pump in a custom setup without a converter. Not sure what volume and pressure are required for a tranny though. Without the converter, it would seem like mostly static pressure (little flow) but I may be missing something.

John

I agree. 65 psi is the minimum needed for proper operation iirc but it sure seems like it wouldn't need a lot of flow just for operating the apply pistons.
The biggest problem as I see it is maintaining adequate lube oil flow during start/stop operation, perhaps a smallish electric pump with a pressure operated bypass/electric pump shutoff activated when the inboard pump is producing enough?
That way reverse could be engaged at a standstill so you don't have to go forward until the reverse apply happens.
That might get a little gnarly. ..

_________________
"There are times when a broken tool is better than a sound one, or a twisted personality more useful than a whole one.
For instance, a whole beer bottle isn't half the weapon that half a beer bottle is ..." Randall Garrett