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Bike engine or Snowmobile engine?



Well I ripped the electric drive out of my EV and sold the batteries, motor and controller.
Now I'm looking for a regular smokey, stinky, noisy internal combustion engine that will put a smile on my face.
(The Electric Car was Boooooooorrrrrrrrrring)

The weight of the car now without drive train is just a hair over 800 lb.

I've got my options down to either a Yamaha R1 bike engine with transmission or the similar Yamaha RX1 snowmobile engine with CVT drive.

There is lots of info on bike engine builds on this forum but not so much on snowmobile/CVT builds.

R1 is pretty straight forward but I would need to come up with a way to reverse.
RX1 is a little more complicated but comes with reverse.

I kind of like the idea of the CVT for use in slalom. No wasting time changing gears.

I'd be interested to hear of any other pros and cons of one over the other.

My Build Log - http://www.szott.com/zot2/zot2.html

Very cool build log, and what a shop. Holy.
I think the RX1 would make a more interesting build. You are obviously an accomplished builder, so you should have no problem adapting something with a CVT. I have no clue how the RX1 would handle your gearbox, but from the R1 perspective, the Suzuki rear end ratio (or would it be front end ratio) may be too short. For my R1, I went with a 3.27, and that gives me just about 100 kph at 6,000 RPM. Anything shorter than that, would probably be annoying.

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Martin


My build log:
viewtopic.php?f=35&t=14520&start=0
My build video:
https://vimeo.com/143524140 password "matovid"

The CVT will have better traction because it corrects for wheel spin automatically.

I've been interested in snowmobile/jetski engines, but had thought to connect them to a normal transaxle at the rear with a driveshaft. For instance an Audi or Porsche unit.

Do you have a good picture of the snowmobile unit?

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Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
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I wasn't planning on using the Suzuki gearbox in either case.
I'm going with a chain drive to a Torsen differential. Overall reduction is by rear sprocket size.
Something like this



I don't have any pictures of either the R1 or the RX1.

Does anyone know if the CVT allows for engine compression braking or does it just freewheel when you go off the gas?

As I recall Snowmobile type CVT's go into minimum reduction on deceleration.
I've got the RX1 service manual in a pdf if you need it. It has a reduction gear driven off the crank nose that runs thru the block to the back, that's why the output shaft is offset from the crankshaft (if I remember correctly, my memory has been faulty a lot lately).

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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

Too Busy recently had a SEC-engined slalom car, but I can't find it (was it buried in one of his many other projects?) It used the CVT, but not without some initial issues with 'on-off' throttle response.

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Warren
Isuzu Pickup/SR20DE, +401 COLD frame
Build Log: viewtopic.php?f=35&t=11601

http://www.locostusa.com/forums/viewtopic.php?f=36&t=17283

This is the F500 thread. The snowmobile engine with a well tuned clutch IS A BLAST. Stupid fast off the line and accelerates like a rocket ship.

The problem I was having was learning to drive a solid axle car. After a few times behind the wheel I was getting the hang of driving it harder into the turns than you think it can possibly handle.

I built (finished really) a R1 powered 7 last year and it was fast. The problem with that one was getting the clutch dialed in to make it drivable. I went with a high ratio clutch pedal and aftermarket coil spring clutch. It's currently getting used hard up in Canada and the guy who bought it is having fun blowing the doors off Spec Miatas at his local track.

Me, having driven both, I'd build the RX1. CVT in a small car with a differential would be damn tough to beat.

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Too much week, not enough weekend.

OOPS I did it again
http://www.locostusa.com/forums/viewtopic.php?f=35&t=17496

Blood Sweat and Beers
http://www.locostusa.com/forums/viewtopic.php?f=35&t=15216

I think if and when I build a 2nd car it will be an AMod autocross car using the RX1 or something similar. Make the car as light as possible, with way too much power, it would be a blast.

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2015 & 2016 EMod Florida State Autocross Champion
2013 & 2014 DSP Florida State Autocross Champion

Scrap Metal Build Log viewtopic.php?f=35&t=14558

If you're truly changing power source because the electrical power was boring (which I can understand after watching the first Formula E "racing forklifts" race this past week-end) then go for the the bike engine. It's the gearbox and being in control of what's happening that is a large factor in making driving fast so challenging, so much fun and so rewarding. You live in TO so you're probably very familiar with snowmobiles....it's the surface that you're driving on, the rough, can't-see-the-undulations-properly, nature of the snow that makes driving a snowmobile quickly so challenging. I honestly can't imagine trying to change gears when pushing a snowmobile really hard...you spend a lot of your time just hanging on and trying to stay upright. Disclaimer - I almost never ride my sled on groomed trails because they're boring, I spend my sled time pushing trails in the bush and on the huge frozen expanse of Lake Winnipeg. I vote for the BEC.

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Bill H
Winnipeg, MB, Canada

Is the R1 really a dry sump motor? All the links I've found say it's wet sump yert I've read on this forum that no mods are required to use an R1 in a car.
How about the RX1. Is that dry sump?

The R1 has wet sump that happens to maintain oil pressure just fine in a car with no downforce.
The RX1/Apex has a dry sump.

Just FYI, the RX1 had carbs, Yamaha renamed the model the Apex when they converted it to fuel injection in ~2006 or 2007.