What's the lightest option for RWD and 100hp currently?

Seems like the DOHC G13 from the Swift GT coupled to a Samurai box reigned supreme for lightest weight option, but those are getting scarce on the ground around here. What's out there that's more current that I don't know about?

Ecotec and whatever alphabet soup from the S2000 seem like they could be options, and there's always the rotaries, but I don't really need that much power and by the time you add in all the stuff to make them run they don't come in so light weight. Is there a RWD trans from Citroen or whatever for the MINI engine, or will the SMART 3-banger bolt up to something from Mitsubishi? What about the tiny Fiesta motor, does someone make a bell for it yet and can it run outside of the car? Does one of the Toyota alphabet soup engines from the iQ fit up to the bell from a truck or something?

Motorcycle won't do, it's going through a divorced transfer case and needs reverse. What else is out there that I don't know about?

What the hell are you making?!?!

Oh, and the s2000 is a f20c making 250~hp. Not a motor to be taken lightly.

I'm about to start down the Suzuki G10 rabbit hole. It's about the lightest and most compact engine I've ever seen, which is why I'm planning on using it. I bet you could get pretty close to 100NA with a hot cam, compression, and opening up the hilariously small intake and exhaust tracts. Early (pre-89 I think) heads are of a hemispherical design and have surprisingly large valves; 36I/30E. Go faster goodies are out there for them.

While not as cool as a G13B, the G13BB seems to have some followers now, too. Late ones came with coil-near-plug, so it should be fairly easy to get going on MegaSquirt (theoretically). It should mate up to the Samurai trans just like it's twin-cam brother, but take that with a grain of salt.

Honda dohc ZC motor. 130hp all day long. You could bury the throttle and go have lunch, she'll still be singing and getting 40mpg. Lol

see if the Mitsu Mirage motor bolts to the Samurai box?

I have a starlet drive train that might work with some massaging. It is yours for the cost of shipping and packaging

How much weight are you planing on pushing around total?

Could motorcycle engine be the answer?

In reply to singleslammer:

You would tempt me with Starlet goodness? I could be there on Tuesday; it's only an 9-hr drive to Colombia...

Currently the vehicle weighs @1800 lbs and came with either a 52hp motor coupled to a 4.11 rear end or @90hp coupled to a 3.44 rear end. I'll be installing 4.55 gears but with slightly larger tires so the total effective ratio will be somewhere between the stock axle ratios. I'm anticipating adding @200# with the 4WD conversion over the stock parts I'll remove, and I'd like to make some of that up with weight savings on the engine and trans vs what was there, and in particular to try and lighten the front of the vehicle as much as possible.

what about the G16A and G16B's from the Sidekick/trackers with 3 and 4 speed autos and 5 speed manuals. More common than the Samurai's at this point and can be hot rodded since they came in the suzuki swifts/geo metro storms/chevy sprints/etc.

I bet with a little tuning a Suzuki F6A (660cc turbo) could hit 100hp, especially since they were apparently underrated from the factory. Supposedly F6A + 5-speed RWD transmission combo from a Jimny (JDM Samurai) is in the <240lb range. I believe it's aluminum block cousin, the K6A, is even lighter too. They can be bought from importers.

Trackmouse wrote: Honda dohc ZC motor. 130hp all day long. You could bury the throttle and go have lunch, she'll still be singing and getting 40mpg. Lol

Sure just need a bell, trans, and reverse rotation diff to make it a streetable RWD setup ... ;)

erohslc wrote:

Trackmouse wrote: Honda dohc ZC motor. 130hp all day long. You could bury the throttle and go have lunch, she'll still be singing and getting 40mpg. Lol

Sure just need a bell, trans, and reverse rotation diff to make it a streetable RWD setup ... ;)

To be fair I did ask wtf was being built and never received info. I assume some sort of Suzuki rally car-esc contraption?

Motor is open to debate, but @ 100 HP, I'd go with either a FordT9 or Toyota T50 for the RWD trans. Spitfire/GT6 trans is very compact, but not so light, and marginally strong enough.

Kind of like the 'What Transmission' thread.

Trackmouse wrote:

erohslc wrote:

Trackmouse wrote: Honda dohc ZC motor. 130hp all day long. You could bury the throttle and go have lunch, she'll still be singing and getting 40mpg. Lol

Sure just need a bell, trans, and reverse rotation diff to make it a streetable RWD setup ... ;)

To be fair I did ask wtf was being built and never received info. I assume some sort of Suzuki rally car-esc contraption?

Yah, that's so.
I've wondered what it would take to make a D series run in opposite direction.

Reverse cams are no problem to have made, and Megasquirt can handle the spark and fuel.
Cam drive tensioners can be fangled to fit the other slack side.
I think the biggest hurdle is the crank driven oil pump.
Might need an external oil pump.

erohslc wrote:

Trackmouse wrote:

erohslc wrote:

Trackmouse wrote: Honda dohc ZC motor. 130hp all day long. You could bury the throttle and go have lunch, she'll still be singing and getting 40mpg. Lol

Sure just need a bell, trans, and reverse rotation diff to make it a streetable RWD setup ... ;)

To be fair I did ask wtf was being built and never received info. I assume some sort of Suzuki rally car-esc contraption?

Yah, that's so. I've wondered what it would take to make a D series run in opposite direction. Reverse cams are no problem to have made, and Megasquirt can handle the spark and fuel. Cam drive tensioners can be fangled to fit the other slack side. I think the biggest hurdle is the crank driven oil pump. Might need an external oil pump.

Might be easier to flip the diff over, run the driveshaft past the diff and chain the two together...

Or does an oil pump from a F20c work?

Having this 99 Vitara has made me realize that a 2wd/2.0L/5-spd Vitara/Tracker/X90 would be a great Locost donor. You'd just need Miata uprights(or similar).

A Ford 2.3 and T5 from a FoxStang should be snaggable for a song and parts are dirt cheap.

In reply to The_Jed: But the FoMoCo 2.3 is not remotely light or compact by 4 cyl standards.

Come on oldopelguy, spill it! Whatcha buildin'?

Chevy 250 inline-6. Trust me

HappyAndy wrote: In reply to The_Jed: But the FoMoCo 2.3 is not remotely light or compact by 4 cyl standards. Come on oldopelguy, spill it! Whatcha buildin'?

Woops, missed the light part.

No one has said b6p or bp mazda? (Miata motors 1.6 and 1.8 respectively) I redline my 1.6 daily hell my daily commute is 4000rpm for 10 miles and shes happy. 100rwph with basic bolt ons is normal along with similar torque

They aren't light, though.

I lost weight in the escort sticking a bigass (dimension-wise) V6 in it.

Morgan 3 wheeler? 1200 lbs

EDIT: Sorry thought you were talking about a car, not just a powertrain. That being said the Morgan 3 wheeler layout is a motorcycle engine connected to a Miata transmission.

might be a thought.

Yeah, so I forgot how light duty these motors were stock.

http://en.wikipedia.org/wiki/Toyota_K_engine#4K

58 hp new. However, it is basically free so it is yours for the taking. That does apply to everyone. Someone start taking stuff out of my basement.

Swank Force One wrote: They aren't light, though. I lost weight in the escort sticking a bigass (dimension-wise) V6 in it.

The KL based motor in the Suzuki (the 2.5L) with the manual trans might be a real contender.