radius arm kit and other handling questions!

[KirstMin]

Hello everyone... after discussing various prices for kit and fitting with several people I have decided to bite the bullet and do some work myself . I've worked out that if I fit a radius arm and uprated torsion bars myself then I can afford for Jonathon @ JHL to fit the nice stage 3 head that I am having made by Morspeed

So I am going to fit either the owen burton radius kit or the ESM kit. Do any of you have experience of either of these kits? Any opinion of which is best? Cam - I know you have the JHL one but what I can save on fitting these bits I can use elsewhere and the JHL one I can't fit coz it's not just bolt on plus it costs a bunch more.

cheers

PS: does this belong in mechanical or bodywork? I never know

[Cam]

Hi mate, mechanical section is fine.

I did not actually know that ESM or Owen Burton do those kits! But now I have seen a picture of them, I recognise them. I have seen them fitted to cars in the past and they are a bit unsightly and do not completely remove the axle tramp, nor do they act as a rear anti-roll bar. They are different to the JLH kit which is a lot better thought out. I personally would not fit the ESM one as I've never been impressed with that type.

The main reason is that the axle is already located on the spring at the bottom of the axle, so any twisting (the cause of tramp) of the axle casing relative to it's original position is going to be most prevalent at the top of the axle as the bottom is already secured by the spring. The ESM kit simply adds an additional bar running parallel to the spring which holds the already held axle bottom albeit a bit more firmly, it STILL does not prevent the top from moving completely. The JLH kit is attached to the top and so the axle is held in two places (top and bottom) which stops it trying to rotate and thus completely eliminates the movement which causes tramp. Also, through the axle, it acts as a rear anti-roll bar which really works well!!

If I were you, I'd fit the uprated torsion bars and cylinder head myself, then save up and get JLH to fit the radius arms if you need them. What sort of power will you be producing? as if it's near the 100 BHP mark, then it might be wise to re-think the axle arrangement and change it for one that can handle more power...

[KirstMin]

100BHP

I was thinking more around the 80 mark

thanks for the info Cam, much help you are! Back to the drawing board to re-jig my plans

[Alec]

Hello Cam,

how is the JLH rear radius rod arranged?, leading or trailing the axle?

Alec

[Cam]

Hi Alec,

You can see the location of the arms in this picture:


One end connects to a bracket on the top of the axle and the other end to a bracket welded to a spreader plate which is welded to the floorpan under the rear seat.

Here is a picture of the brackets on the top of the axle:

[Alec]

Hello Cam,

I see the idea, it is also an 'A' frame profile for sideways location.
What distance apart are the pivot points as the forward one seems far to the rear of the front shackle axis or is that due to photographic distortion.
Won't that tend to try and rotate the axle as it moves up and down?

Alec

[Nigel2]

Very interesting. Similar to to set up on the Volvo Amazon (I have got a 122s as well). The Amazon of course has coil springs with internal tele. damper. The rear end certainly sits on the road with 115 bhp going through it. Did not realise they did kits for Minors. Now we are going to us a Minor all the time (see previous post) more food for thought! Best of luck with it -

[Alec]

Hello Cam,

I have just remembered that Aldon, many years ago did a twin radius arm set up, it may have been a Minor or possibly an A35. They retained the leaf springs but linked the axle to the spring with a short swivelling link. Basically the idea is the springs had no location function whatsoever, the radius arms did that.

It would obviously be a major modification and possibly not worth the trouble, for a road car anyway.

Alec

[KirstMin]

Hi Cam, thanks for the piccies, that certainly gives me an idea of the difference in substance between the two sets.

I wonder where owen burtons and ESM's testing and R&D came into it? they are both very different in set up to the JHL kit.

Also, you've got an escort axel right? What about standard axel - does this system work with that as I think i am going to stop at approx 80BHP with my standard axel and toughened halfshafts. Anyway, i think that's the max my new head might produce (maybe less).

[Cam]

What distance apart are the pivot points as the forward one seems far to the rear of the front shackle axis or is that due to photographic distortion.

It's not THAT far away in reality. There is a bit pf perspecive distortion in the photos.

Won't that tend to try and rotate the axle as it moves up and down?

Slightly, yes, but in a very controlled manner. The important issue is that it does not allow the rotation of the axle under power which causes the tramp. It locates the axle really well. There is practically no side-to-side movement at all.

I have just remembered that Aldon, many years ago did a twin radius arm set up, it may have been a Minor or possibly an A35. They retained the leaf springs but linked the axle to the spring with a short swivelling link. Basically the idea is the springs had no location function whatsoever, the radius arms did that.

It would obviously be a major modification and possibly not worth the trouble, for a road car anyway.

Well, if it prevents annoying axle tramp then it has application, but if the car is being used 'normally' then yes, I agree, it has limited application and would not be worth the trouble!!

Also, you've got an escort axel right? What about standard axel - does this system work with that as I think i am going to stop at approx 80BHP with my standard axel and toughened halfshafts. Anyway, i think that's the max my new head might produce (maybe less).

Yes, I've got an Escort axle. The JLH system will work with pretty much ANY live-axle arrangement. If you can weld the brackets onto the axle tube then it will work!

80 BHP will probably be OK with the standard axle and hardened half-shafts, but it will depend on how you use the power. If you dump the clutch a lot and generally abuse the axle, then it might still snap, but you will probably be OK.

I would try out your car first before splashing out on radius arms, as depending on your driving style, you might not feel the need for them.

[KirstMin]

80 BHP will probably be OK with the standard axle and hardened half-shafts, but it will depend on how you use the power.

well i'm not one for dumping the clutch

I would try out your car first before splashing out on radius arms, as depending on your driving style, you might not feel the need for them.

You mean try it out with the new head and extra power before I decide?

cheers

[jonathon]

Thanks for the sales pitch Cam
The triangulated radius arm we do is deaigned to eliminate two problems with leaf springs. One is axle tramp and the other location specifically sidewards
The length of the arms has been calculated to replicate the rotational motion of the axle under compression or extention.
The kit that ESM and most other dealers sell is the old O.Burton one which is designed to eliminate axle tramp. C.Ware and C.S Autoclassics are the only other producers of radius arm kits. It can seem deceptive, but in general most dealers only stock the MMC Bath(old O. Burton kits)The other two dealers I mentioned plus myself are the only ones who sell our/their own designs. The C.Ware kit and indeed the whole series 111 kit is loosly based on C.Streets original kit which is now superceeded by his own series 1V.
My advise on all modifications is to try before you buy.

[KirstMin]

It's all very confusing

I didn't know C.ware do one and ive been in and out of that place.... It's certainly NOT on their latest modification/update list that they use to sell various modifications to punters and no-one mentioned it to me on my MANY trips and conversations i have had with them - even discussions about axle tramp! They must keep secrets from me as a test OR they've stopped it?

[jonathon]

The radius arm kit will normally be sold as a part of C.Wares Series111 kit. This particular kit has been in existance since the 80's and remained generally unchanged since then, (I believe) Don't know why its not been mentioned.
I'd shop around as they don't seem to need your business, or take the time to explain' their' design.

[KirstMin]

Well I had their series III suspension and handling kit upgrade not a long time ago and I certainly don't have a radius arm kit, they didn't mention it and it's not mentioned on their website as part of the package

http://www.morrisminor.org.uk/ser3_sus.htm

I don't think they do it or maybe they have stopped doing it. In fact, it's not in their series III update literature I got from them only 1 month ago either.

[bigginger]

doesn't seem to be mentioned in the catalogue I've got either - about 5 years old, with all the updates...

[jonathon]

Not even as part of the Series 111 ? Oh well all the better for the rest of us ehh!!

[bigginger]

No, not there.

[KirstMin]

Well I'm glad we've got that sussed

now back to my visual basic programming - its easier

[bigginger]

It isn't...