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A Good Castor Angle?
the_big_1 - 24/7/16 at 07:31 PM

Hi guys,

The Haynes book shows their top wishbone createing a 5.30 degree castor angle.
Is this a good or is there a better angle to ensure self straigtning steering using the Escort MK1 steering rack and Cortina uprights etc?

And is this correct:

Haynes shows offset from cetner line of top wishbone tie rod end, 9 mm (Mid point 111, tie rod 102 and 121)

5.30 degrees from 0 = 1.69mm of of set per degree of castor? (5.30 degree / 9 mm of offset)?


Cheers!

mark chandler - 24/7/16 at 08:02 PM

5 - 7 degrees is recommended

the_big_1 - 24/7/16 at 08:07 PM

Great stuff!!!

Are my above maths correct?

If so, 6 degrees would be approx offset of 10mm? so 101mm and 122mm???


Cheers!!!!!

907 - 24/7/16 at 09:34 PM

Mine are offset by 22mm. This is just about enough.


Escort rack & Cortina uprights.


Wish bone dims extra castor
Wish bone dims extra castor


[Edited on 24/7/16 by 907]

the_big_1 - 24/7/16 at 09:52 PM

Hi ya,

What castor does the 22mm give you?


Cheers!!!

907 - 24/7/16 at 10:18 PM

I don't know offhand what the distance is between the top and bottom joints on a Cortina upright
so I can't give a figure in degrees.

I don't like degrees anyway, and always work to dimensions.
For instance, I can easily measure 2mm of toe in, but to work it out in degrees and then measure it in degrees would stump me.

Paul G

907 - 25/7/16 at 06:54 AM

Doing a rough measurement of my Cortina uprights with a tape the distance between the balls is 220mm
so 22mm would equate to 5.71 deg.

Judging by how it drives I wouldn't go less than this.




Mark says 5 to 7 in his post.

I'd say aim for 6.

I did make Uncle Ron's book w/b's to start with that had half the amount of castor but you tossed a coin as to which side ditch
you were likely to end up in.

Paul G

the_big_1 - 25/7/16 at 09:56 AM

Hi ya,

Do you have a pic of your bottom wishbone with dims I could nosy at?

johnemms - 25/7/16 at 10:47 AM

907 - 25/7/16 at 12:48 PM

My bottoms are straight from Uncle Ron's book dimension wise.

No pic of them individually, just a GA.

I know. One missing
I know. One missing

the_big_1 - 25/7/16 at 01:22 PM

Great stuff!!!

What's the bottom ball joint from?

907 - 25/7/16 at 05:41 PM

quote:
Originally posted by the_big_1
Great stuff!!!

What's the bottom ball joint from?




Cortina, but no one else seems to mount them underneath.

the_big_1 - 25/7/16 at 05:52 PM

Really does look good.
Did you do the design to the book? I thought Cortina had an angle part where the two top bolts fix?

mark chandler - 25/7/16 at 06:53 PM

My cortina uprights have maxi ball joints on the bottom, a little lighter I guess

NSF lower wishbone 23 Oct 2005
NSF lower wishbone 23 Oct 2005

the_big_1 - 25/7/16 at 06:57 PM

Hi ya,

I am trying to find a simple design for the lower. I guess the Maxi is good being simple flat mounting.

the_big_1 - 25/7/16 at 07:06 PM

Hi again.

Looking at the fab picture of the top wishbone, its 5mm longer than the book (Book shows 175, above 180) from bush mounting centre to end of threaded mounting.
Do i take it that the lower is also 5mm longer? So book is from bush mounting centre to middle of ball joint (Book 340, so make new 345)???


Cheers!!!

907 - 25/7/16 at 08:02 PM

quote:
Originally posted by the_big_1
Really does look good.
Did you do the design to the book? I thought Cortina had an angle part where the two top bolts fix?



Thanks.

I start off intending to go by the book ...... But then I sort of drift away from it.
I have a saying; "the drawing is only a guide."


The angled part got amputated, which looses the two 10mm holes. But two more 8mm holes were drilled to
make up. Because the gusset plate has a large round hole and the b/j locates in this from the underside.
Effectively the w/b, and therefore the cars weight sits on what remains of the b/j flange.
I can in fact remove all four bolts and the car just sits there.

I hope you understood that.

Paul G

the_big_1 - 25/7/16 at 08:07 PM

Got ya!

So did you use the design of a Maxi ball joint plate as the idea and the cut the angle off, and drill teo extra?

Did the two original holes align with maxi style or did you do them from scratch on the plate?


Cheers!


Carl

907 - 25/7/16 at 08:26 PM

quote:
Originally posted by the_big_1
Got ya!

So did you use the design of a Maxi ball joint plate as the idea and the cut the angle off, and drill teo extra?

Did the two original holes align with maxi style or did you do them from scratch on the plate?


Cheers!


Carl



I went into my local Austin/Rover (as it was then) and asked for Maxi b/j's.
I might as well been asking if I could rape his daughter.

500m down the road was the Ford dealer.
"Tomorrow morning about 10o'clock mate".

Once you've got them in your hand it's sort of obvious what to do.

the_big_1 - 25/7/16 at 08:30 PM

Just a quick question.

Do you know if the maxi ball joint diameter is the same as the Cortina one?

Need to know what size hole to use to allow the cortina one to pass through through the plate.


Cheers!

907 - 25/7/16 at 09:27 PM

quote:
Originally posted by the_big_1
Just a quick question.

Do you know if the maxi ball joint diameter is the same as the Cortina one?

Need to know what size hole to use to allow the cortina one to pass through through the plate.


Cheers!



No idea of the size of the maxi b/j

I did find a pic of the Cortina b/j mod.


Description
Description

the_big_1 - 25/7/16 at 09:30 PM

Hi ya!!

Perfect! The hole is actually a cut out.
I can measure the cortina ball joint and work out cutout size etc!

Top man!!!

Minicooper - 28/7/16 at 06:07 PM

Hello,
I have drawn out the Haynes Roadster front suspension and I can only ever get 3 degrees of castor so my question is where is this 5.3 degrees coming from?