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John Brown
John Brown SuperDork
10/21/08 7:29 a.m.

Remember that any engine that goes 150,000 miles while pushing a 5,000lb barge around at 80mph on Michigan freeways while knocking down 25+mpg SHOULD be on the top of your list (they are mine ;) )

  • 1: Lincoln Continental 4.6L FWD
  • 2: Olds Aurora 4.0L/ Cadillac Northstar 4.6L
  • 3: Ford 3.8/4.2L in FWD or RWD
  • 4: Ecotec 2.0/2.2/2.4L

These haven't been explored and really SHOULD be. Most can be had in the $300-600 range and all make between 150hp and 305hp.

Jensenman
Jensenman SuperDork
10/21/08 9:21 a.m.

We had a Saturn Ion in the shop with a supercharged Ecotec. It would be a bit tougher to keep the wheelbase short since the S/C is in front of the motor, but I bet it would make for a very entertaining ride.

Beerguy
Beerguy New Reader
10/21/08 10:34 a.m.

Google "iron duke super duty" 100hp per litre DOHC iron duke. GM made a lot of junk in the 80's but at least they raced all that junk.

96DXCivic
96DXCivic Reader
10/21/08 11:18 a.m.

So what kind of changes will I need to make in general to front wheel drive engine vs. a front rear engine to make it MR?

Keith
Keith SuperDork
10/21/08 11:38 a.m.

Attach it to the right transmission. And that's the problem with a lot of the Honda engines - they spin the wrong way, giving you 5-6 reverse gears and only one forward. You might have to play around with intake manifolds and definitely with exhaust manifolds.

96DXCivic
96DXCivic Reader
10/21/08 2:18 p.m.

So I was hoping to find a transverse mounted engine so that I could build a smaller car. What cheap transverse mounted engine can I find a transmission that will spin the right way in order to build a mid-rear car?

Jensenman
Jensenman SuperDork
10/21/08 2:26 p.m.

Actually, any FWD transverse setup will work, provided you do not turn the powerplant around, e.g. with a Honda powerplant the tranny would be on the right side of the car and with anything else it would be on the left, viewed as if you were sitting in the drivers' seat.

It actually winds up being a mid motor car that way. To see what I mean, look at any FWD car. You'll see that the engine is actually ahead of the CV axles, meaning that in a FWD car most of the powerplant's weight is carried ahead of the front axle centerline.

If you put that same motor in a mid engine car, now the weight of the engine is between the front and rear axles, giving you a better weight distribution and better polar moment of inertia.

MustangSix
MustangSix Reader
10/21/08 2:43 p.m.

Don't FWD Honduh engines turn the wrong way? That makes them harder to adapt to RWD applications. Flip the rear end, I guess.

Besides, isn't the right answer on this forum "Miata"?

96DXCivic wrote: So I was hoping to find a transverse mounted engine so that I could build a smaller car. What cheap transverse mounted engine can I find a transmission that will spin the right way in order to build a mid-rear car?

It doesn't come to mind usually, but the Ford CVH engines have the same bellhousing pattern as the older 2.0 OHC and other four banger Fords. It's easily adapted to RWD, not too heavy, are cheap as dirt.

In a 1000lb Locost you only need about 125 hp to be scary fast anyway. 300 hp engines are only good for bragging rights and tire smoke.

Keith
Keith SuperDork
10/21/08 2:53 p.m.

Having driven a Locost with 175 hp and one with 300, I can tell you that the 300 hp ones are still faster :)

96DXCivic
96DXCivic Reader
10/21/08 3:53 p.m.

So I can use a Honda or any transverse mounted front wheel drive drive engine as long as the engine is in front of the CV axles and it will be fine has a mid rear setup. Right?

Jensenman
Jensenman SuperDork
10/21/08 4:04 p.m.
96DXCivic wrote: So I can use a Honda or any transverse mounted front wheel drive drive engine as long as the engine is in front of the CV axles and it will be fine has a mid rear setup. Right?

Give that man a see-gar and his choice of prizes off the top shelf.

If you get a chance, look at a MR2 or X 1/9 engine layout; it's a FWD transaxle moved to the rear with whatever mods are necessary to run the shift linkage.

I'm currently head scratching a swap with a Mopar FWD transaxle which is a two cable setup, pretty easy to adapt to mid motor.

96DXCivic
96DXCivic Reader
10/21/08 4:10 p.m.

Now just to find sizes of some engines. Where can I find CAD files of engines that I can use to design a chassis around?

Jensenman
Jensenman SuperDork
10/21/08 4:28 p.m.

BTW, Honda motors will work just fine in a mid mount application. There's a kit car called, IIRC, the K1 Attack that uses an Accord drivetrain mid mounted. The only thing that would make me hesitate: this puts the motor directly behind the driver in a left hand drive configuration, meaning the car will start out a good bit heavier on the left since the motor's a good bit heavier than the manual tranny. This can certainly be worked around, it's just something to keep in mind.

John Brown
John Brown SuperDork
10/21/08 4:46 p.m.

Three words:

Right Hand Drive

96DXCivic
96DXCivic Reader
10/21/08 4:51 p.m.

I am planning on registering for the road as a kit car so I would like to use LHD.

Jensenman
Jensenman SuperDork
10/21/08 4:54 p.m.

RHD is legal here in the States. Look at all the mail vehicles out there; I have two non postal worker customers who drive RHD Cherokees as daily transportation.

96DXCivic
96DXCivic Reader
10/21/08 4:58 p.m.

I know it is legal but I wouldn't really want to drive a RHD on the road.

fiat22turbo
fiat22turbo SuperDork
10/21/08 5:31 p.m.

Yeah, but it is a Locost. That's only a difference of the width of your butt plus maybe a little for the tunnel. It isn't as though you'll be driving the right-hand drive P71....

Also, since it is your car you could put three seats in it and drive it from the center.

Apexcarver
Apexcarver SuperDork
10/21/08 5:55 p.m.

and you can put the shifter on the right anyways..

noisycricket
noisycricket New Reader
10/21/08 6:09 p.m.
fiat22turbo wrote: Also, since it is your car you could put three seats in it and drive it from the center.

I was planning on doing that with a front drive VW. Hell, the shift linkage is all wacky anyway, just locate the steering column in the center, move the pedals over, and put the shifter where the driver's seat used to be.

Nothin' in the rules where I play says I can't do it...

Jensenman
Jensenman SuperDork
10/21/08 6:53 p.m.

I'm with you about the LHD thing. Everything else I own is LHD, I'd hate to have to learn all over again. Heck, I moved the front brake on my mountain bike to the left side of the bars so it would match the motorcycle.

I guess that means I'm too stupid to be able to switch back and forth.

One thing I just thought about: if you are building a Locost type car, that means you'd want to use readily available steering racks. There are not many RHD racks available here, so you'd have to get one from overseas or have one made and that's pricey. Or you could use an Appleton or Jack Knight rack with the center pinion, but that's pricey as well.

fiat22turbo
fiat22turbo SuperDork
10/21/08 6:57 p.m.

Porsche 924 essentially used a RHD A1 rabbit rack mounted backwards, but I know what you're talking about.

Jensenman
Jensenman SuperDork
10/21/08 7:54 p.m.

Yeah, if you 'flip' a rack to move the pinion to the other side, you have reversed its direction. Makes for interesting operational characteristics. <

Generally, 'front steer' cars (rack mounted in front of the axle centerline) have the pinion mounted BELOW the rack, while 'rear steer' cars (rack behind the axle centerline) have the pinion ABOVE the rack. So it's possible to take a 'rear steer' rack, flip it end to end, and then use it in a 'front steer' application.

exST165
exST165 New Reader
10/21/08 9:18 p.m.
In a 1000lb Locost you only need about 125 hp to be scary fast anyway. 300 hp engines are only good for bragging rights and tire smoke.

I don't disagree, but IMHO the trick is to keep the car under 1,000 lbs!

What are some of these drivetrains going to weigh all up? Engine with all the fluids and accessories, driveshaft and rear axle are going to add up quick.

I'm seriously looking at building a Locost 7 for the Challenge (notice I didn't say which challenge!) but I'm getting nervous about the weights of some of the engines we're looking at. A Ford 2.3 Turbo might be a sweet engine capable of 400 hp, but at 450 lbs (or so I've read) plus a 8.8 solid rear axle capable of taking the aformentioned horsepower is going to weigh a good 600 to 800 lbs by my wild guess. Keeping that car an honest 1,000 lbs is going to be quite a feat.

I would love to build a sport-bike powered Locost 7, between the super light weight and the sequential transmission they look like a real hoot on the track. Not so nice around town but sacrifices are necessary. The big issue for me would be to do it under the Challenge budget.

Thomas

noisycricket
noisycricket New Reader
10/21/08 9:28 p.m.

The neat thing is that the weight loss also decreases the load on the drivetrain so it doesn't have to be so beefy.

Look at trucks... most of the time, a one-ton has the same engines as a half-ton, but the transmission and rearend are one or two grades beefier, the U-joints are twice as huge, etc. Same power, different expected loads.

You need an 8.8 to put up with a 5.0 in a fullsize, but for years Ford only ever used the 7.5 in the Mustang GT. Or look at the RX-7 guys making 300-400hp with the stock rear diffs, they don't hurt them because they can't load them heavily enough unless they dig out the slicks and abusive driving.

Keeping things under 1000lb is going to be difficult. My gut feeling is that a transverse mid-engine setup will be the lightest, since there's no rear axle, so probably that D16 drivetrain would be just the ticket. That said, supposedly an entire Swift/Metro 1-liter engine/trans combo is under 300lb... be a bit down on power, but why settle for 1000lb when you can try for 800?

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