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Lightest, biggest capacity engine at 100 hp?
Lippoman - 30/9/06 at 11:12 AM

Hi!
As the reg's in Sweden call for a certain curb weight per power I'd like to find the lightest, biggest capacity engine at or around 100 hp/73kW. This would put my build at a target weight of 500 kgs. Due to packaging reasons all V engines are out. Any ideas?
I would like some more grunt at low rpms than the 600 cc engines I've found so far can deliver.

zilspeed - 30/9/06 at 11:30 AM

I would say GSXR750, but it's a bit too powerfull.
Example - 2000 model year, 138bhp, revs to 14,500

rayward - 30/9/06 at 11:40 AM

does it have to be design power?, or can you limit it with a rev limiter, or restrictor plates on the inlets for example?.

Ray

russbost - 30/9/06 at 11:49 AM

One of the Japanese 600's?

JackNco - 30/9/06 at 12:50 PM

arnt the Regs really tight on bikes in sweeden?

chrisf - 30/9/06 at 01:57 PM

Why not put some huge steel plates on the floor. I bet they can be removed at a later date.

--Chris

smart51 - 30/9/06 at 02:28 PM

Rover's K series 1.4 16V engine makes 103 PS and weighs 100kg. Caterham use them.

Toyota's 1.0 3 cylinder engine (Aygo, Yaris, 107, C1, charade, sirion) weighs only 68kg but makes only 68 BHP.

Simon - 30/9/06 at 04:06 PM

Time for a revolution I'm afraid!

ATB

Simon

Lippoman - 30/9/06 at 04:51 PM

rayward: Yes, it has to be design power, no dyno tests or restrictors allowed.
smart51: Rover K: I think that will be too wide for the application, also it would put the engines weight over the rear axle, I'd like it approx 400 mm forward... are those weights including gearboxes?
Simon: Well, the new reg's have hiked the power from 10 to 15 kW/100kg, and we swedes are a very patient (mellow?) bunch...
chrisf: There is already some extra weight needed to get it up to 500 kgs (if calcs are correct), too much "creativity" in reading the rules only gets you to have to re-test.
The reason why I'm looking at building a BEC is primarily the sequential gearboxes, as I'd like to incorporate a paddle shift in the build. Also the chain drive which I intend to retain gives possibilities to play with the location of the engine for distribution of weight and inertia...

Thanks to all so far, I still hope to find some weight info on engines in this power region.

Nick Skidmore - 30/9/06 at 05:09 PM

GSXR1400??

Oil cooled so no water plumbing.

Good torque and about 100bhp, 140ish after test when you fit GSXR750 (oil cooler) cams and use power commander.

smart51 - 30/9/06 at 05:30 PM

quote:
Originally posted by Lippoman
Rover K: I think that will be too wide for the application, also it would put the engines weight over the rear axle, I'd like it approx 400 mm forward... are those weights including gearboxes?


Engine only weights, sorry. K series engines were fitted to later rover 100s. They had a narrower track than rover 214s. You could use 100 half shafts.

Bike engines with only 100 BHP have very low torque values, that is unless you find an odd bike engine with large capacity but low rev limit. There probably is one somewhere.

Catpuss - 30/9/06 at 05:31 PM

It may be worth looking to see if Sweeden have the bike 100bhp limit. If so local breakers may be able to source you a 1000cc engine or above that has a limiter.

Alternativly you could just get something like a GSXR1300 or GSX1400 and set up a megasquirt to limit the revs.

whitestu - 30/9/06 at 06:14 PM

What about the Honda Pan European V4.

"doesn't need to read any sales pitch sanctimony. A powerful and swift cross-country touring bike, the ST1100 packs 100bhp and fallons of torque from its 1084cc V4, with optional anti-lock brakes and traction control.

Stu

jimgiblett - 30/9/06 at 07:04 PM

IIRC my Eurospec Yam 02/03 R1 motor was 100bhp. Lots of torque and if you by chance removed the restrictors in the throttle bodies you would then have 150bhp+

- Jim