By Dusty on Unrecorded Date: Edit

In designing a 6x6/track rig, which end should the engine be in? I'm thinking it probably doesn't make a lot of difference as people and cargo will tend to balance everything out. I am leaning towards rear placement for a couple reasons:

I think a lighter front end will lead to better performance--ie, climbing over logs, getting out of the water, and in snow. I can lean back or move cargo to lighten the front more--the engine stays where I put it (hopefully!).

I think a rear-mount engine would tend to be quieter from the drivers seat.

I am more likely to bang the front end up--the engine would be more protected in the rear.

If at some point I find a need for PTO or hydraulics or _____ a rear-mounted engine is more likely to be accessible and near whatever it is I might want to power.

Any other thoughts?

By Alfred Cushman on Unrecorded Date: Edit

Why are you trying to reinvent the "wheel"? The perfect ATV was built 30 years ago, "The Cushman Trackster".
The great news is that The "Updated Trackster" will soon be in production, for a sneak preview go to;
www.wildernessvehicles.com

By Tim Wafer (Iflyrctoo) on Unrecorded Date: Edit

Funny
I just ran across that site seconds before you posted it!
Tim

By Dusty on Unrecorded Date: Edit

1) I like re-inventing. The wheel isn't perfect!

2) Thanks for the link.

3) A bit more on #1:

I want a vehicle that does what I want it to do, not what everyone else thinks it should do. That includes working on Interior Alaska powder snow, fitting down skinny snogo trails during moose season, and running on thin ice without getting me wet. An Argo or Max might do what I want, but for the first time in several years I again have time and space to build toys, and I think both can be improved (from my perspective, at least).

The trackster (BTW, there are still a few around up here, although they function primarily as lawn decorations as near as I can tell) is heavy--I wouldn't take it anywhere I won't take my snogo, and that's just where I want to be! I have doubts that a hydrostat would work (more than once) at -40--I often run at -30, and -40 is not at all uncommon (I stay home below that). When I go through the ice (and I do occasionally) I want to be able to get out.

My design criteria so far include:

Light weight - I'm thinking steel frame and aluminum tub/body.

Tracks running on tires - the tires should make it float a bit higher, hopefully enough I can climb out of water onto ice (but I plan on having a winch/come along in case I can't). The tracks will be 15X1" used snogo tracks, perhaps with studs (re: climbing out on the ice).

Nothing that isn't likely to work in the cold - no hydraulics, and preferably 2-stroke powered (I'm thinking an engine out of a Tundra, possibly a Tundra IIR with electronic reverse).

Capable of running in mud and muck and things that are hard on bogey wheels (ie, fire-killed black spruce poles in snogo trails) so I can chase moose from it in the fall.

I just found this site a couple days ago-until then, I though I was the only person in the world that would consider building something when you can buy one kinda-sorta like what you need. I'm anticipating a greatly shortened learning curve by begging/borrowing/stealing ideas from here. Thanks in advance!

By Douglas MacCullagh (Dougmac) on Unrecorded Date: Edit

Dusty -

Some ideas to steal might include the old Army Weasel or Otter amphibious carriers; controlled differential steering maybe off a Weasel or T-16 carrier; maybe mount the engine next to the driver for weight balance and PTO access (front PTO for winch or capstan, rear PTO for propeller or towed implements); Air cooled engine (no water to freeze). Sounds like a neat idea. Go for it!

By phil on Unrecorded Date: Edit

Look at FWD type cars, I an using a GEO/Metro 3 cylinder engine for a Coot type vehicle. The engine trans weighs only about 150lbs. Being it is water cooled you can have heat in the cab.Independant disc brakes will get skid steer motion and these parts are cheap and around the yards. The GEO engine is 16" long and the trans is 13" long, the overhead cam makes it tall about 23" but if you are building your own can design around it.E-mail if you want photos of the components

By pressman on Unrecorded Date: Edit

Phip good idea on the geo. I would like to see what you are planning and some pictures.
Lawpressman@aol.com Thanks Larry

By Russell Lee (Bigkodiak) on Unrecorded Date: Edit

Phil
I had given thought to the metro engine as well. My only concern was that I would have to make a gear shift plate that would only allow up to so many gears. I could see myself now trying to do 80 in the woods.
Good luck
Russ

By Eugene Kochnieff on Unrecorded Date: Edit

Hi Russell,

Gee it seems a waste to not use all your gears!!!

Just lower the final drive so first gear becomes an extra low pulling ratio and top gear is a safe speed for smooth roads.

Bye for Now Eugene.

By philb4 on Unrecorded Date: Edit

I use the trans with a welded diff to get 1 drive shaft out which gos into a samurai transfercase.This drives either samurai 3.73 rear or subaru 3.90 rear giving a top speed of 35 mph with 30" tires.The low range gives 5mph top speed.If that isn't enough gears I can't help you.The samurai transfer case needs 13" input to output and weighs 40lbs.

By Eugene Kochnieff. on Unrecorded Date: Edit

Hi Philb4,

What you say suggests the samurai transfer case has a ratio of 7:1 between high and low. Is that correct i once owned a suzuki 4WD and the tranfer ratio was something like 2.5:1. My current 4WD (mitsubishi) has a transfer ratio of about the same also.

So if i'm close you either have a 5Mph and 12.5Mph machine or a 35 Mph and 14 Mph machine.

Just some thoughts.

Bye For now Eugene.

By philb4 on Unrecorded Date: Edit

The low in a samurai is 2.26. I am comparing top speed high to 1st gear low. www.jeeptech.com has a gear tire calculator that you can work with.I also have an additional 4.1 reduction into the transfer case. Sorry it was not clear.

By chris Davison on Unrecorded Date: Edit

Im currently building a v.w.powered 8x8 the rear seat is directly over the transaxle just as a stock bug. the irs axles come out exactly in the center of the hull front to rear. There is a cadillac disc brake on each and a 15 tooth rc 60 sprocket driving a 30 tooth on a jack shaft this jack shaft drives the axles.Engine and trans weigh about 340 lbs together. In the rear will be a polaris water pump for propulsion in the water. There is more room in the cab than a bug.A roof rack between the roll bar and windshield. and what looks like a sand rail frame above the 4 rails that hold the inch and three eights axle bearings. All this will fit into a 13x6 aluminum hull .090 thick so the weight is slightly to the rear and there is no fear of hard brakeing on the down hill it will come out of the water easelyand will have the advantages of air cooling. the hull is 24 inches tall and should draw 4.6 inches of water that leaves almost 20 inches out of the water so it will be real safe in the water on a windy day not so some of the factory builds.I will be able to fish all day from it or drive up the Rubicon trail.