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[zefarelly]

why did I paint my axle casing . . . 2 radius arms looks like the way to go

I have a pair of escort ones on the shelf which are of no use I also have bracketry for them

[calex_fr]

Whaoooooo, I just start to understand !
(I think you complicate things unnecessarily, Olympic is not a Ferrari).

Well, perhaps Phase One is like this :



Phase Two like that but with one control arm :



My car is a normal phase two, like Joe :

[calex_fr]

[Dave-M]

Continuing on from the drawings I posted earlier.
Rod, the single link to the diff housing top was my initial thought but I decided not to go that way for 2 reasons. a) the distance from the axle c/l would have to be greater than from c/l to lower link. b) there is a possibility of clearance issues on full bump.

Paul, well written and very understandable and most helpful.
Here are a few thoughts to explain why I am going with the layout as in my drawing.
On the phase 2 shell there is a boxed in area just behind the front mounting position (for the trailing links) you have used on your Phase 1 and the top link would have to pass through this and then would have clearance problems with the seats.
Hence the diff / tunnel mountings.
I want to retain the original lower arms in my car and just fabricate two new upper arms of the same length.
The problem is that they will need modifying and here is the reason (I think) the whole geometry of the botton link and damper mounting is wrong:-
Under the pressure of producing the Phase 2 as quickly as possible the trailing arms were made to the wrong dimension, the distance used was taken from the axle c/l to the front of the mounting box moulded into the floor pan and not to the pivot point.
If you look at the A, B, & C dimensions on the side view drawing you will see they are the same (well they are within 0.1").
If the traling arms had been remade shorter the pivot would have been directly below the axle and the damper would have been vertical, which is, I am sure how it was intended.
However, having found the error, and probably having a pile of arms already made, the easy way out was taken and the axle mountings were angled back behind the c/l.
Nobody complained and the fault was never designed out.
The upshot of all this is that the original trailing arms will have to be shortened at the front end by around 1.125" to bring everything back in line and the axle pivot brought forward by the same amount.
If you look at the side elevation drawing it will all become apparent.
I have ordered the Tubing and rose joints and will keep you posted.
One other advantage of the proposed 4 link layout is that it will be much kinder to the propshaft uj's. If you look at the angle of the diff at bump and droop you will notice quite a large angular change and this coupled with a very short propsahft put all the angular loads on the uj at the gearbox end. With the four link it splits the angular deflection to equal amounts at each end.
Paul, when you weighed your car what figure did you get? I have seen figures varying from 12.75 cwt (1428lb/650kg) to 17.25cwt (1932lb/878kg) and need some accurate figures to calculate the spring rates.
Regards
Dave

[Dave-M]

[calex_fr]

Yes I agree with you.

Can you do it simply and quickly ?


_________________
Alexandre Contat

from France

[calex_fr]

[Dave-M]

Alex have you used the Google translator?
If there are any parts you do not understand, please ask and I will try my best to help.
Dave
_________________
Ph.2 Ford 1500 GT
GT with Rochdale Chassis

[Paul Gething]

Rod

With regard to your comment

[Paul Narramore]

As a one time design draughtsman, I ought to be following this but I'm afraid it left me a while back. To me it should be a comparatively simple task. Design a rear suspension which works. Don't deviate (too far) from accepted norms so it doesn't. Leave off the rear suspension units and jack the axle up and down and watch what goes on.

However if someone actually get's a better system to work, I'll be the first to congratulate you.

[calex_fr]

Paul Gething,

is your car ?




_________________
Alexandre Contat

from France

[Paul Narramore]

The simple swinging arm you have drawn looks far better than the chunking great effort found on the Ph2, however I can't see it would work.

What you propose is that the bottom of the suspension unit would have a ring instead of a pin mount. What happens when (say) the nearside wheel rides up over a kerb? The tyre/wheel will rise up and the suspension will compress. What happens to the bolt which goes through the bush in the ring mount? It cannot twist and I doubt if there would be enough give in the bush. It works on a motorcycle because the swing arm only moves in one plane, whereas on a Ph2 it must swing about it's pivot as well as from side to side.

Another thing. By using a simple square section bar, you've lost about 4" (100mm) as the suspension unit has to sit on top of the swinging arm. To recover this, the top mounting in the bodyshell would need to go up 4" too.

Can you see the difficulties?

Yes, that's Paul's car.

PS I've put this reply on the wrong thread too (damn) or have I. What happened to the CAD drawings?

[Paul Gething]

Oui, Alex. cela est ma voiture. C'est un Phase1.

Un autre photo



Mon autre voiture.....Le meilleur laxatif connu.........


Le même virage comme le Rochdale est photographié.

[TonyS]

Rear Suspension "DUFFY"

[Paul Narramore]

Tony

I like the race car simplicity of Richard Parker's front and rear suspension on Duffy. Compared to the standard Ph2 suspension, it just looks as if it works OK. Of course the old engineering maxim was "If it looks right, is usually is right".