Hello, I'm new here so please be kind. I'm looking to start building a Locost later in the year, ideally based around the book chassis, at the moment I'm still looking into the design side of things.

I'd like to use an escort rear axel, as in the book but combine it with a Zetec engine (1.6 or 1.8) and a sierra box. Now what I need to know is; can the escort axel cope with the torque that the zetec will produce, or will I need to use a sierra diff and hubs on the back?

I realise that the original RS2000 was a pretty quick car as were the MK1 & MK2 escort rally cars, were they running stock axels or were the diffs and half shafts up rated to cope with the additional torque?

As the choice of rear end directly effects my choice of chassis design, I need to sort out what I'm going to do before I start cutting metal.

Thanks

Hi there and welcome.

I had this question a while back when I was thinking about mating a Rover V8 up to a Cortina axle.

The concensus seemed that you're good to go up to about 150BHP, but over that and you risk knackering it with enthusiastic driving.

If youve got loadsamoney, i believe that Quaife do upgrade bits for the escort axles, but I wait to be corrected on that!

Bear in mind that this is purey opinion: i dont think anyone has actually analysed the gear teeth and halfshaft stresses.

So, my uneducated estimate is that up to 150BHP is OK...

HTH,

Ed.
P.S. 150 horses will still give you Power to weight ratio of about 200BHP/Tonne. You'll beat most GTIs off the lights with that anyway.

[Edited on 11/3/06 by ed_crouch]

[Edited on 11/3/06 by ed_crouch]

chances are you will spin the wheels due too lack of grip before you damage the axle, RV8 included.

T'is a very valid point.

I'll second that, the english axle is pretty reliable up to around 150bhp. Above that and you need to look at the Atlas (if sticking to Ford parts), though it's a heavy old lump.

Back in the days of MK1/Mk2 Escort rally cars they used to break an awful lot of halfshafts on the english axle -- on a rally car once you get to about 150 bhp in a special stage car the standard English axle is pretty useless, The works rally cars used the Capri 3 litre (a Salsbury axle not unlike the MGB/MGC unit), private owners who only did club events and didn't have to comply with homologation usually fitted a Jaguar MK2 axle which in those days was in easy and cheap to find. Later versions of the Salsbury axle was fitted to the Cortina and Capri and hese became a widely uised source of cheap stong axles.

In a road car the english axle will take 180 bhp without problem.

In a Locost the lightness isn't going to help much -- basically fatigue breaks halfshafts any english is going to be 30 years old and seen an awful lot of torque reversals already and remember the engish axles was designed back in the days of 500x13" cross ply tyres that provided a lot less traction than a modern 205/50x15.

To fit an english axle then try and uprate it by heavy duty parts is just plain silly when stronger and more suitable ratio units are available in the Ford range -- in any case the Escort width axles are a bit on the narrow side even for a book build.

The Salsbury axles come in various ratios and widths starting with the Escort one, the Cortina axle is 4inches wider than the Escort.



[Edited on 12/3/06 by britishtrident]

Thanks everyone, so basically I'm same to use an escort axel (I think the 1.8 zetec is only 115BHP) but a Cortina or Capri one would be more suitable, especially given the age of the axel. Well, that's good to know as it means I can get away with pretty much a book chassis.

quote:

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In a Locost the lightness isn't going to help much -- basically fatigue breaks halfshafts any english is going to be 30 years old and seen an awful lot of torque reversals already and remember the engish axles was designed back in the days of 500x13" cross ply tyres that provided a lot less traction than a modern 205/50x15.




[Edited on 12/3/06 by britishtrident]

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