6 chain VS 4 chain Attex models

[jpswift1]

OK everyone, lets compare and contrast all the good and bad points of the 4 chain Attexes and the 6 chain Attexes. I have a ST/295 that I am restoring, along with a bunch of other 6x6's, and its the 4 chain model. I thought that it might be a good canidate for a high horsepower motor because there are only 4 chains and the power goes directly from the transmission to the axles. Lets hear some thoughts.

[Don]

You must have a later model ST295 there. I've never seen that particular machine with the 4-chain set. They say the rear chains will wear out quicker on that system because of the full reverse bend, but I've never noticed any difference. The only drawback I know of with your chain set is the lack of clearance for a low center-of-gravity engine mounting.

Good Luck with it- how high horsepower are we talking, for curiosity's sake?

[jpswift1]

Don, I checked and it said 1975 stamped on the frame rail. I forgot that the engine sits higher up in it.....thats right, it needs to because it would hit the chains if it was any lower. I thought about doing 670 Rotax LC. I know where one is and I could get it cheap. This is just a crazy idea, but it might work, who knows. Thats a lot of plumbing to worry about. I might just do a 400 JLO or Briggs Vanguard.

[whipper-ag]

It's funny that you brought this question up, because I was staring at my Attex last night wondering how I was going to lower the motor for lower center of gravity. My Attex is a 4 chain car & so was the Attex I jumped the 4 cars with. I figured I can move the engine back 3" & down 2" & buy a longer belt & it will still clear the chains. I just have to fabricate a new engine mount. I like the 4 chain set-up. There's 2 less chains & 4 less sprockets in the car. (LESS WEIGHT = MORE SPEED) If you jack up an Attex & you jack up a Max you will notice that it takes less energy to spin the tire on the Attex partly because your not turning thru a jackshaft. Which I never liked much on my Max. I always thought the Attex dominated racing because of their much simplified drive train. Everytime you add something to a drive train it creates drag & uses more HP which ='s LESS SPEED. What's critical in the 4 chain set-up is that everything is in perfect alignment, especially the idler. I fabricated my own billet aluminum idler w/ better bearings to do just that. Use better bearings on everything you do, cause bad bearings cause induced drag. Which consumes HP = LESS SPEED. Some day I'll build a 4 chain springer Max & get rid of the jackshaft. Of course, if your not looking for more speed perfect alignment is still everything.

[jpswift1]

So Whipper, you would say that this would be a good machine to go the "performance" route with and throw some sort of big motor in there? That idea sure seems to make a lot of sense......the more resistance, the less HP, and the less speed there will be.

[Don]

JPswift1, I think you may have a "cross" machine that's had the frame switched at some time in it's life. As far as I know, Attex didn't produce an ST295 after 1972, and they all had six chains. If you decide to go the route of a 400 JLO, let me know and I'll get you the mounts out of an ST400 and it'll be a simple bolt-in operation. I think the big liquid-cooled sounds like a more interesting project, though.

Don