Tractor Pulling

[slinky]

Me again!

So we were at the workshop this weekend discussing silly ideas for taking a sherpa van racing... (don't ask.. we were being silly, but it involved two engines in the back of circa 900hp, and a standard diesel donk in the front... anyway, I digress)... And we started talking about tractor pulling...

And here came the question, it is not uncommon for tractor pulling tractors to run multiple engines (I've seen video of 12+ alcohol burning SBC's), how the hell do you get 12 engines to run one diff???

Cheers,

slinky
587racing.com

[Liszt]

Always wondered how they did that.

They seem to have different configurations of engine layouts such as in line in a cross shape etc.

I thought that they must drive a common propshaft perhaps through a belt drive or a viscous coupling of some sort.

[chuntington101]

i thought they noramlly ran 2000bhp supercharged big block chevies!! or alternatively 3 aero V12s or a coupld of turbo prob engines!!!!

still very good question! its gotta be one F*CK OFF diff to cope with all that torque!

thansk Chris.

[matt_fp]

The way I would do it would be to use X number of engines to drive hydraulic pumps which in turn drive hydraulic motors, either one per wheel or one through a diff onto both wheels...........

But thats just me, I've no idea how they actualy do it

Matt

[anonymous-user]

Calling Barry Ashcroft ..........

[chassis 33]

Some industrial gearboxes can run multiple inputs, never used one but seen them, thats how I've always thought they did it.

Regards
Iain

[Liszt]

But would you really need a diff? It's all in a straight line, isn't it?

[chuntington101]

i think they only use one gear, and i don't think a diff is needed! infact i think they aim for wheel spin to drive the rigs forwards not outright trtaction. so a diff could be a hinderance!

thanks cHRIS.

[anonymous-user]

AFAIK they use brakes to steer and I'm pretty sure no gearboxes as such are involved.
Mike

[Barry Ashcroft]

Gear boxes and diffs are used with no diff how are you going to split the striaght drive from the engines to drive two rear wheels??

In my brothers tractor Red Alert which is an alchol superstock we have a choice of 4 gears different tracks require different wheel speeds the pull is made by generating high wheel speeds to rely on friction to pull the tractor down the track.

With multiple engines a cross box is used to link all the engines to one common output shaft to drive the diff.Two engines in a line are linked crank to crank. Rockwell diffs are used which come out of large excatators and lorrys but with very high outputs machines with 6000hp+ use what is now in the pulling world as a super diff specially made for the job in hand with big monster gears and needle rollers but expect to pay about 5k for one.

Click on the link below for details of how they link 5 Chevy big blocks together on a friend on mine tractor "Desperate Dan"
www.tractorpulling.freeserve.co.uk/howit.htm

Also look at
www.tractorpulling.co.uk
www.pullingworld.com

Regards

Barry

[anonymous-user]

I knew you'd be along soon with the answer mate !

Got your car back yet?

Mike

[gary_tholl]

I absolutely love PH. Where else would you find first hand info on such a variety of subjects????

I remember going to a monster truck/tractor pull show when I was a kid. It was awesome. The noise was almost all I remember.

[dilbert]

I reckon that the engines would all be fixed to the same propshaft, or possibly on "dog clutches". The obvious solution to the differential issue is just to use a "spool type" diff.

I guess the dog clutches would allow you to start the individual engines separately, and the diff would give strength.

I have to say though, I'm not sure how the main clutch would work. Maybe it'd be direct drive, with some scheme for dropping the driven wheels onto the deck when you've got sufficient revs.

>> Edited by dilbert on Friday 2nd December 17:34

[chuntington101]

ready barry's post above and follow the links! shows how its done!

hmmmmmm i wonder if you could mount 5 Griffin engines like that? hehe

Chris.

[chuntington101]

here is a link to what tractor pulling is like when it all goes a little wrong!!

Chris.

[VYT]

Barry Ashcroft said:

Gear boxes and diffs are used with no diff how are you going to split the striaght drive from the engines to drive two rear wheels?? In my brothers tractor Red Alert which is an alchol superstock we have a choice of 4 gears different tracks require different wheel speeds the pull is made by generating high wheel speeds to rely on friction to pull the tractor down the track. With multiple engines a cross box is used to link all the engines to one common output shaft to drive the diff.Two engines in a line are linked crank to crank. Rockwell diffs are used which come out of large excatators and lorrys but with very high outputs machines with 6000hp+ use what is now in the pulling world as a super diff specially made for the job in hand with big monster gears and needle rollers but expect to pay about 5k for one. Click on the link below for details of how they link 5 Chevy big blocks together on a friend on mine tractor "Desperate Dan" www.tractorpulling.freeserve.co.uk/howit.htm Also look at www.tractorpulling.co.uk www.pullingworld.com Regards Barry

'Cor Blimey last time I had anything to do with tractor pulling a couple of Jag V12's and a Fordson Major back end was all it took.

[Pigeon]

chuntington101 said:

here is a link to what tractor pulling is like when it all goes a little wrong!! Chris.

Your link seems to have gone a little wrong too...

[anonymous-user]

WTF ?

[slinky]

That's a dirty great radial..

Bloody marvellous!

slinky

[Pigeon]

seight said:

WTF ?

WW2 tank engine, by Chrysler or Lycoming I think. Problem: "how do we make a great big powerful but compact engine for a tank without taking ages over it?" Solution: "take five existing straight sixes and stick them on a common crank."