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MG MGB GT V8 Factory Originals Technical - coil spring dimensions?

Could someone measure the freestanding height of a stock MGB front suspension spring and the diameter and give me the figures? I'd like to have both CB and RB versions. Thanks,

Jim
Jim Blackwood

Jim,

Paul Hunt has that info on his website, The pages of Bee & Vee" :

http://www.mgb-stuff.org.uk/wn_suspensionframe.htm

Click on spring specs.
Carl Floyd

Thanks Carl, that's given me most of what I need, but now I find I also need the fully compressed height. Nothing's ever easy, is it?

Jim
Jim Blackwood

I had a set of RB front springs garage that I had used for two or three years. Freestanding height measured 10 inches.

Replaced with a set of lowering springs that are 1 inch shorter.
Jim Miller

Jim,
I have just sent an email to you with a chart of the spring rates and fitted dimensions for the CB roadster and CB GT models.

I hope it comes out OK at your end.

Cheers , Pete.
Peter Thomas

"but now I find I also need the fully compressed height"

Good luck with that, Jim. :)
Carl Floyd

Pete, it was usable, and does help as it confirms what I thought were the correct spring rates. Paul's table shows ~100lbs/in which is closer to the rear springs. I'd guess he got the ends of the car switched there.
Jim, thanks. Again, more helpful verification.

I had to approximate the compressed height from the suspension of my own car, but since it's almost on the bump stops anyway it wasn't a tremendous leap. About 5-1/2" should be a good working figure, although 5" without coil bind would be the safe way to go. That means 4-1/2 to 5" of working range or nearly double that at the wheel and I don't believe the front suspension is capable of moving up and down much more than 6".

Hey Carl, think maybe I ought to find a spare spring and clamp it down in the bench vise to get that measurement? :O (No, really if I was considering something like that I have a press that would let me do that with a 1-1/2" acme screw down the center to keep it from getting away, leaping out of the thing and leaving a large swath of destruction in it's wake.) Unfortunately that would only give me the coil bind dimension though.

Jim
Jim Blackwood

Jim,

This may add a little to the info. From the Special Tuning manual for MGB tourer and GT:

Three coil springs listed

fitted deflection at working load rate
height working load

7" 2.965" 1030lb 348lb/in

6.6" 2.49" 1193lb 480lb/in

6.14 2.49" 1193lb 480lb/in

The manual also gives details of the standard springs for CB cars up to (I presume) its publication date of 1969. These are:

Tourer

coil diameter 3.238in
wire diameter .498"
free height 9.9 +/- 1/16" (1.6mm)
static laden length 7" +/- 1/32" (.8mm) at
load of 1,030lb

GT
same order as above

3.28in
.54in
9.1 +/- 1/16" (1.6mm)
6.6" at load of 1.193lb +/- 20lb.

Now I cross my fingers and hope the formatting half way holds.

Regards
Roger
Roger T

Ok, should have known better.

The first lot of data reads correctly for the four figures eg first line comprises:

7"
2.965"
1030lb
348lb/in

The four headings are (in this example):

fitted height
deflection at working load
working load
rate.

Roger
Roger T

This thread was discussed between 18/07/2006 and 20/07/2006

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