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Thiokol Imp's

Bulldog1401

Anybody seen my marbles?
SUPER Site Supporter
O.K. here we go.... It has been suggested to me by more distinguished members that I start an Imp modification thread..... Please reply with your model, year, and upgrades.... I have seen some world class Imps on Ebay and in this forum, and believe that any experience, positive or negative, is important. So please don't hesitate to share yours. Thanks. :letitsnow:
 

pixie

Well-known member
SUPER Site Supporter
My Imp is a 1404, about a '78. It has 1100 hours and came with all the orange parts. It must have been used with a ram-steer drag.
I added the winch ( with Amsteel Blue line) and the "skidderplate" and the little roof and side panels. And a trailer hitch.
It makes a good little skidder in winter but hasn't enough ground clearance to use ( on my land ) in the summer.
The only other modifications were made by rodents to the seats....
 

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Bulldog1401

Anybody seen my marbles?
SUPER Site Supporter
Wow.. I have never seen an Imp worked that hard. I see you have the drop center tracks, which i am told help to steer in other than snow conditions. How do you supply and control your hydraulics?
 

pixie

Well-known member
SUPER Site Supporter
Truth be told, the Imp doesn't drag much more wood than I can with the ATV and a log arch.

There are 2 banks of 4 valves each supplied by a belt driven pump. The pump is one of those ones that you can only see with one eye at a time :yum: It had all the hydraulics in it when I got it.
To run the winch, I lock a lever 'on' and the winch has it's own control on a cord.

I haven't put it to any tests without snow. The land is just too rough.

Interior pic. Upper bank is just visible and lower one is down to the right of the seat. Tank is by driver's right elbow/upper arm on back wall.
 

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mtntopper

Back On Track
SUPER Site Supporter
Here are some pics of my older restored 1974 Thiokol 1404 WT Imp. I sold the Imp several years ago. It only had about 460 total hours and had been completely restored to like new condition. It was sold to a neighbor family that was extremely disappointed in the tracked Argo performance which they purchased to access their cabin in the winter. It was a great performer in the snow. I probably should of kept it but it did sell to a great family that is still using the Imp today. :thumb:

Full cab modified for additional seating of up to 6 passengers.
Added safety lighting for additional safety in high traffic areas.
Wide angle mirrors for greater visibility in rear of machine.
12,000lb electric Ramsey winch that was hardly used or needed.
Interior was insulated and carpeted to make it warmer and quieter.
On dash drink holder for holding coffee cup, p/u keys and beer can.
Garfield on snow shoes graphics on side and back headed to cabin.
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Snowcat Operations

Active member
SUPER Site Supporter
I really like those full body Imps. What is there PSI with standard Wide tracks? Anyone know? Did the Imps ever come with a OC12?
 

Snowcat Operations

Active member
SUPER Site Supporter
BULLDOG1401,
What are your desired modifications you want to do? I read that you wanted a dual bettery set-up. Give us your ideas.
 

Bulldog1401

Anybody seen my marbles?
SUPER Site Supporter
I want a cab like MTcrawlers so I can seat 6, I want to lift the cat 2 inches by doubling up the cross axles that mount to the leaf springs, so I can run deeper cleats. Used cleats for 1200 series cats are readilly available, and would allow me to add an extra belt, for an asymetrical wide track. I want to replace the electric winch that was stolen from the front of the machine before I got it, and do a full carpet and insulation job. I have begun consolidating the dual wiper motor system into a single motor with linkage system from an early Ford Bronco (66-77 type) with mixed results. I would like to hear of a better way. A parallel vertical wiper system like on busses would be nice.
 

Snowcat Operations

Active member
SUPER Site Supporter
I dont know anything about wiper arms except they can be damn hard to get off after 30 years! Anyway I need to get a new VW wiper motor myself. I know some people have done the dual wiper motor conversion on the snow tracs which seems to be a popular conversion. I suspect I will be having problems trying to get my linkage back right. I may need to do the conversion myself.
 

mtncrawler

Bronze Member
GOLD Site Supporter
Bulldog, before you remove the dual wiper motors consider that with two motors if the drivers side fails it's an easy switch to replace it with the passenger side one. I think this is a redundant feature that Thiokol purposely built into the machine.
 

Snowcat Operations

Active member
SUPER Site Supporter
Thats a good idea since my VW wiper motor called it quits on me one day in the field. What a pain in the arse it was to drive back with crappy vision.
 

Bulldog1401

Anybody seen my marbles?
SUPER Site Supporter
That is a good point. Simple and reliable is usuall best when things go wrong.
 

Bulldog1401

Anybody seen my marbles?
SUPER Site Supporter
That looks like a good choice for a winch. The synthetic rope is a good choice also, in that is easily as strong, and does not kink up if not carefull rewound on the drim. Once kinked, the wire rope will always be weaker at that point. While shipboard, I did some towing using double braided nylon line. Incredibly strong stuff.
 

nutsster

Member
Be very careful with some of the mods you are planning on doing!
A considerably more agressive grouser will make it hook up much better, but add more stress to the Clark 4 differential. The C4 differential is not known for taking any abuse very well. Rebuilds are very expensive on any differential. (I've been there!) :toilet:
Plus adding two inches under the axles to lift the machine will place the axles 2" closer to the track at the top. You must also figure out a way to lower the differential to keep the same track geometry.
My Imp 1402 had this mod done to it prior to me purchasing it. It gave me fits for two winters before I ripped it out and replaced it with a torsion axle setup. My differential is tipped down considerably at the rear end to lower it. You can't do that in the front without adding drive shaft problems. It may be much easier to find some drop axles used on the early Sprites to accomplish the drop required. The gearing changes some with drop axles on the C4 to releave the stress on differential's guts. This was needed for it to work in the early Sprites, since they are much bigger than in Imp.
 
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nutsster

Member
Here is probably the most modified Imp in the world. It started out as a Thiokol 1402 built in the early 70's. Originally, it had no cab and a Wisconsin air cooled engine. The early models 1402 were the test bed for the 1404, run year round in all conditions and terrain.
I purchased this cat from Bill at Snowtrans. It looked like this when I brought it home. As you can see there was a lot work ahead!

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It previously had a Ford 2.0 L engine installed and a lifted chassis.
My first goal was to build an engine cover and a cab on the unit. I wish I had taken more pictures of it during this process, but didn't in fear of failure of the project. :smileywac


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I immediatly set out to improve the suspension and track setup. I decided to go to a wider asymetrical track as shown above. After running it for a year, I was not happy with the ride and constant manual shifting of the transmission. :1062
I also had problems with the track striking the axles due to the lifting (spacers between axle and springs) and geometry changes.
Finally, it all had to go...
After a month of calculating, I ordered torsion axles to replace the leaf springs. :4_11_9:
I decided to move the front axle forward 6" over the original wheel position to gain some more surface area. That also required the front idler to be relocated forward and longer tracks made.
My desire was to make an all new custom track with strait grousers to add more clearance too.:thumb:
In the middle of all of this, I set out to do something about the manual transmission. I found out that the 2.0 L engine was German built and used in the Ford Pinto between '72 - '74. It was the best engine ever made for the Pinto, with very few automatics. However, after two months of searching, I found a Pinto collector in St Louis that had two automatics for this engine. BINGO!
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I ran this cat about 250 miles this winter in all conditions. It finally has become the machine I set out to have after four years of testing and improvements. It handles and feels nothing like an IMP with the new torsion axles and tracks. The automatic and torsion axles make it much smoother to operate compared to a 1404. It is probably between an IMP and LMC1200 in overall performance and handling. :thumb:
 

Bulldog1401

Anybody seen my marbles?
SUPER Site Supporter
Could you please give me the dimensions of the new suspension that you built, and explain the drive sprocket to track relationship problems you had? Also, why are some of the torsion axles facing forward and others backward? Thanks.
 

Teeoster

New member
Hi BullDog,

I started out with the same set up as you have. I am in the middle of a snow cat version of a resto-mod on it also. So far I have stripped the machine down and started the fit up of a 2.8 liter v6 engine. The engine is the 6 cylinder big brother to the v4 that comes in the IMP's (I still had to paint it Chevy Orange!). Much like Nutsster's 2.0 it has the same bolt patterns on the block which enable the use of the existing bellhousing and motor mounts. I am trying to make the engine take up as little space as possible right now which means fabricating accessory mounts, radiator, exhaust, ect.
Once the engine, and related cowling is in place and happy, I will start down the line on the rest of the power train. In the mean time I have gone through the oc-4 rear, 3 speed transmission, clutch, drive shaft. I have some of the suspension components gathered up, but still have to decide on the best approach for my needs. For my Michigan winters the 24inch drop center tracks will probably work the best.
All the guys here have been a great help so far. Allot of experienced builders that can help us from making the same mistakes:) Nutsster's machine is definitly the most moded out 1400 machine out there:respect: And Mnttopper's old 1404 is so sweet, what a detailed machine:thumb: Looking at stuff like that gives me allot of incentive to keep plugging away:)
 

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Snowcat Operations

Active member
SUPER Site Supporter
Very nice! Looks like we have another detailed builder joining the ranks of NUTTSTER. I love this forum since there is no other place you can go and get the info you can get here. Keep up the great work. what are your other plans for this macine? Extra wide tracks?
 

Bulldog1401

Anybody seen my marbles?
SUPER Site Supporter
Looks like some very good work being done there. The V-6 will probably be easier to find parts for. This is the ford ranger engine, right? I had a 1988 Ford ranger with a 2.9 V6 in it, made in Germany. I had a for mechanic tell me that they are all tested at 12000 RPM at the factory to check for primary balance. Then when installed, they are rev limited to 7000, so they last very well. Unfortunately, if you paint it chevy orange, it may not start every time, and if so, probably will not run well.
 

Teeoster

New member
I got allot of mixed reviews on the ford v-6 engines. I built this one from a truck 2.8 and had to put the front timing cover, intake, water pump and lower pulley from a earlier car engine on it. The car stuff made the engine about 2" shorter, which is critical for the amount of room left for a radiator. The truck block and crank are much stronger than the previous car versions. I think the 2.9 is similar, but has fuel injection and cannot be made "shorter" because the fuel injection intake is not interchangeable with the previous car stuff.

I rebuilt the whole engine, put a brand new ford 2 barrel carb, new points distributor, and a so called “RV” cam in it. It should be a sweet running engine once completed. In hind sight I might think about going with an entirely different power train, but this will definitely get the job done. Hp should be around 130 and should run smooth through 5,000revs. The old v-4 had about 50 hp and sounded like it was coming apart at 2,500!
If anyone ever decides to go this route please call me so I can save you all the R&D time (586)206-1240.

The OC-4 looks like brand new inside and out now, with all new bearings in it. I think it should hold up as long as I avoid putting too much multiplied torque into the front of it. This can be accomplished by not running the front trans in 1st gear. If it does blow, I have a Ford 9 inch rear end (5.13 gears) that is itching for a new home. This would save weight and get rid of all the old tractor junk:)

Not sure what larger idler wheels you’re asking about?? I would like to replace the old sprockets, but not sure where to get new ones from?? Any suggestions on that would be appreciated.
 
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Snowcat Operations

Active member
SUPER Site Supporter
Now thats a funny comment about the Ford 9 inch! My brother and I were contemplating the same thing for my Swamp Spryte but I have decided to just have the OC-4 fixed and save the historical value of the Amphibious snowcat. We also have plans to build a snowcat from scratch and use a Dana 70 in the rear.
 
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