scratch built bombi

[jeapadrenaline]

hey snowcat guys.
as the title states, i have a scratch built "bombi" which i call "the beast"
i didnt start the project and so far have not finished it yet, but getting closer.
its using an nissan a14 engine with a 4 speed manual tranny and what i believe to be a nissan/datsun rearend that has been narrowed down and flipped to get the right direction of travel since the whole drivetrain is mounted backwards from what it was originally in a car or truck.
i have a long thread with pics and a vid or two on my fave forum.
youre wecome to browse there and/or view my build.
http://kramerville.net/mbn/ubbthreads.php?ubb=showflat&Number=9586#Post9586
i update on regular basis, sometimes daily. i list the good news and also the problems i am having.
enjoy the build, and please leave comments or hints, tips or tricks either here or on the other forum. i am always looking for help, like right now with my tracks and how to keep them on the vehicle.

thanks guys
james

 

[dave_dj1]

Looks good so far, about the tracks, it looks like to me that you need taller "keepers" on the inside. If you look at J5 bombi's you will see the exterior of the cleats are rounded to allow the tire to sit down into, and tall keepers inside.
Keep up the good work.

 

[jeapadrenaline]

well, unfortunately taller keepers on the inside are not possible, as they would not fit past the brake rotor and caliper. but i am thinking that with 4 bolt heads per cleat i may be getting too much traction and be forcing the tracks off at every turn ecause the tracks don slide sideways enough.
so i am now modifying the track cleats. drilling larger hole on the outside and sinking the bolts inside the cleat.
73 cleats per track, 4 hole per cleat = lots of work lol
thanks for the encouragement, i will eventually get this thing to perform right.

 

[dave_dj1]

I just read your entire thread on the other site and I must say you are determined! I'm sorry that some scumbag ruined your home and belongings. I hope they catch him and hang him by his nuts!
I want to build a tracked vehicle so I'm quite interested as to your dilemma of not having enough reduction. I "assumed" that by having a drive sprocket half the diameter of a tire/wheel combo that it would gear it down enough, maybe that isn't the case.
One thing I just thought of is that if your rear axle has a tall gear like a 3:08 or something similar. To check it turn both sprockets one revolution and see how many times the driveshaft turns, mark everything of course.
What about using a completely different transmission? Maybe find one with a much lower 1st gear like an old SM465 or SM420, both 4 spds out of trucks. Maybe make it chain drive?
Good luck and keep us posted.
dave

 

[jeapadrenaline]

dave, i hope you get to building your dream, and please post a build thread, here or on mbn.
as for gearing, i am running a 4.11:1 diff. transmission i am not sure, but whatever you end up using, make sure to incorporate either a second transmission or at least a transfer case out of a 4x4. my original plan was to build it 100% from scratch, in which case i would have built the tub around the running gear, meaning V6 engine with two transmissions in line, then into a rearend. but i found this abandoned project, an couldnt pass up the deal i got on it.
also, it may be worth it to try and find actuall bombi or similar drive sprocket and track to incorporate into your build.
if you have any questions, please do not hesitate to ask, as learning from mistakes can get real expensive real fast.

 

[Snowtrac Nome]

just find an m21 weasel differential they are a dime a dozen around here and steer just like the bombies the plus side on the m29 diff is it's 2 speed with a low gear and a road gear

 

[jeapadrenaline]

dds
i may just be interested in finding one of those m21 weasel diffs.
do you have any dimensions for them? and maybe gear ratios?
i cant seem to find any of those diffs around here, may haveto somehow makea long distance purchase and ship somehow.

 

[Snowtrac Nome]

I know where there are a bunch at I may even know where a nos one is in a shipping crate I think sprocket to sprocket they are about 5 feet the weasel was about the same width as a bombi or imp it may take some time to track down owner ship of the few weasels I know of in the back country but if there is a crate with one at lees camp I know the owners there it's as easy as haggling out a deal.

 

[JimVT]

one other member has done about what your doing. he posted pictures of a GM install.

 

[jeapadrenaline]

any idea what the thread name is? i have read a lot of threads on the forum and havent come accross it as far as i remember.

 

[JimVT]

1975 Bombi Resto/Repower - Forums Forums - Off Topic Forum FUN

 

[jeapadrenaline]

thanks jim
too bad the poster in that thread never finished.
myself, i am back to the drawing board. probably gona rip out the transmission and the diff, then go all hydraulic.

 

[jeapadrenaline]

hey guys, i hope someone on here has the information i am looking for.
i need to find detailed pics, and possibly measurments and such about the suspension on a BOMBARDIER J5. seems to me that my project was modeled after a j5 and maybe i can make the suspension work the same way. right now i have it welded solid since it was giving the track too much slack and machine kept throwing tracks.
also, is there anyone in the BC Interior who has a J5 ???? would love to go check one out in person.
thanks for your help guys.

 

[jeapadrenaline]

hey guys
since you all are like me and love pics and vids, here ya go...

http://youtu.be/bBI7O7bXZaY
http://youtu.be/mDMWzG3RCTc


well, i tried to embed the vid on here.... dont know how

 

[dave_dj1]

Nice vid, thanks for sharing and I'm glad you got the bugs ironed out of her