What an Amazing Little Engine!

[85 Cutlass Brougham]

In my search for an engine with high power density and low weight, I came across this little 600cc (36ci) 2 cylinder snowmobile engine from Ski-Doo. It puts out an astonishing 115-125 hp! It's a 2 stroke direct injection engine with a fuel cooled computer, and meets current EPA emissions regs too. The weight is low (maybe 100-120lbs?), and it redlines at 8100 RPM. It takes technology from the Evinrude E-TEC marine engines to make it all possible. Now this thing is useless in a G body, but think of the possibilities for fuel economy and acceleration in a lightweight car (Mini, Yugo, Geo Metro, Fiat 500, Trabant, etc). In a snowmobile it gets over 20mpg. In a small car weighing around 1200lbs with the right gearing it could top 35mpg city and run 12's in the 1/4. The only negative is that it is liquid cooled, so you would need a radiator, and it has a pull start so you would need to figure out how to adapt it to an electric start and a normal automotive alternator to make it work in a car. I figure it has a shaft style output, so maybe it could be mated to a Harley trike transmission ( they have reverse) through a custom primary with a built in starter and alternator.

Here's the PDF on it:http://corp.brp.com/NR/rdonlyres/3F...CB76F60B74/0/2007_01_31_ETEC_backgrounder.pdf

 

[joe_padavano]

In my search for an engine with high power density and low weight, I came across this little 600cc (36ci) 2 cylinder snowmobile engine from Ski-Doo. It puts out an astonishing 115-125 hp! It's a 2 stroke direct injection engine with a fuel cooled computer, and meets current EPA emissions regs too. The weight is low (maybe 100-120lbs?), and it redlines at 8100 RPM. It takes technology from the Evinrude E-TEC marine engines to make it all possible. Now this thing is useless in a G body, but think of the possibilities for fuel economy and acceleration in a lightweight car (Mini, Yugo, Geo Metro, Fiat 500, Trabant, etc). In a snowmobile it gets over 20mpg. In a small car weighing around 1200lbs with the right gearing it could top 35mpg city and run 12's in the 1/4. The only negative is that it is liquid cooled, so you would need a radiator, and it has a pull start so you would need to figure out how to adapt it to an electric start and a normal automotive alternator to make it work in a car. I figure it has a shaft style output, so maybe it could be mated to a Harley trike transmission ( they have reverse) through a custom primary with a built in starter and alternator.

Here's the PDF on it:http://corp.brp.com/NR/rdonlyres/3F...CB76F60B74/0/2007_01_31_ETEC_backgrounder.pdf

It's definitely impressive, but peak HP alone is not enough. It's area under the curve that matters (at least to me). Look at the original Honda S2000. The 2.0 liter engine was rated at an impressive 240 HP. The problem was that all the power came in between 7500 and 8500 RPM. The HP curve was nonexistent on either side of the very steep peak. Some people enjoy constantly rowing the gears to stay in the power peak. I prefer a big block... :lol:

Now, with a CVT, things get a little different. The engine stays at the power peak (or at the operating point of peak efficiency - that's a programming choice).

 

[85 Cutlass Brougham]

The S2000 was a fun little car, but it was too heavy to be fast with that torque curve. A friend of mine used to have one, and it was a lot of fun to throw all those revs in! I am in no way suggesting this for a heavy car, but for a very light one in which low end torque is a liability due to a lack of weight to plant the wheels at launch (Look at a VTEC swapped mini for example). I have this equation I seek to balance, and from time to time I work on finding ways to solve it. The equation goes like this: Can you run low 12's or high 11's in the quarter in a 4 seater car that has a trunk and the ability to get 35mpg in the city and 50-60mpg on the highway? Now to do this, you need a small displacement engine as the minimum amount of fuel required to keep an engine going usually goes down with size. You also need a light car and a power to weight ratio of 1:10 or better. Now weight is a real liability to everything in a car from handling to braking to acceleration. Reduce weight, and you reduce the need for tires and brakes to be very large to get great results. That's the Colin Chapman school of engineering ( founder of Lotus) and he had a point. The only thing that suffers is occupant room inside the car, but everything has a trade off.

This is not to say I don't like torque. I do in a heavy car. I just like to play with alternative ideas from time to time. I like my G body, but it's a bit of a "Me Too" car. I want to balance the equation in a way no one else yet has and build a car that is completely unique one day. If I can't do that (most good ideas have been tried at least once before), I can at least have something almost no one has ever seen done before. I don't know about you, but if I am at a car show, I would be more interested in the oddball car than the well done red small block Camaro parked next to it. The Camaro I understand, the oddball I don't. I can learn from the oddball and that is why I would like it better. This is one of the reasons I like Trabants. Only a handful exist in the US (less than 500), and none are seriously modified. It also has unique Communist engineering with features rarely (or never) seen on western cars. A Trabant with a 600cc smowmobile engine driven through a trike transmission would be relatively inexpensive to build, but very unique. The only thing holding me up is my lack of ability to speak German, a current lack of money for this sort of thing, and that I can't seem to find a Trabant.

 

[pokertramp]

That is why Lotus built the Elise. It has an almost 200 hp Toyota engine in a car that weighs less than 2,000 lbs. Throw a turbo on an Elise and you will outrun pretty much any car from the factory. IIRC an Elise with an aftermarket turbo will outrun a Lamborghini, Ferrari and many other cars not to mention that in stock form will out maneuver any car that is stock on the road today.

This is just my 50 cents, If I had a choice between a $150,000 or more super car or a Lotus Elise, I would pick the Lotus any day, as for looks, I would pick a Lamborghini Murciélago.

That would put the S2000 to shame,lol.

 

[85 Cutlass Brougham]

I absolutely ADORE the Elise! It is an amazing driver's car. It may not have the top end speed (even with a turbo) of a top supercar like an Enzo or Veyron, but where it counts it has it in spades. Weight takes all the fun out of cars, something Lotus has always recognized since their early days and the original Elan. It's why I love playing with these equations. You can make ordinary parts from average cars like a Camry do wonderful things when you remove the weight. V6 Camry brakes on a car like a Lotus/Caterham 7 would be like putting 14 in Brembos on a G body. Plus, with weight out of the equation, low end torque is not as critical for driveability.