MGA broken front spring!

[Matchless]

I could buy "new" springs but they are generally Chineeseium and I have this pair of springs from a BMW kit, they have the same dia wire, same internal and external dimensions, two slight issues, MGA spring is flat both ends, new spring has flat one end only and it needs shortening, second issue is that the new spring has one coil less for the same length, I am quite happy to heat the last coil and bend it down, then grind it flat, or I may be able to find a rubber spring end to seat the spring, but what about the one less coil, should I cut the spring a bit longer? or should I try to compare the pressure (using my hydraulic press) needed to compress the old unbroken spring to a set length ......................................I am a tight bugger and the springs are too similar not to use them! The old springs are original from 1960 so did quite well ! may have sunk a bit .

 

[dobbslc]

I don't know about cutting them down but I can say the old ones will definitely have sunk a bit, I replaced the Surf springs all round with quality standard height ones and after measuring it the truck stood 2" taller all round!

 

[Nick67GT]

Try finding some ‘New old stock’ or good used items. I find that this is generally the best route when faced with oriental copies.

Won’t comply with your financial approach though!

 

[Cobbler]

When I broke a spring on my MGA back in the Neolithic period I think it was MGB GT springs I fitted, I can’t recall the details, but remember it rode very slightly higher. This could have been due to the old ones being knackered, the memory is a bit sketchy now as I sold it when wifey was pregnant & could no longer get in it, sons 48 now!

 

[Master-of-none]

Ideally you want to know the BMW spring rate which would be measured in kg/mm & can be converted to lb/inch as used by MG.
A quick look at the Brown & Gammons site says MGA front springs come in a range of lengths and spring rates, so decide if it is within the range.
If you cut a spring, you reduce the whole spring rate by the percentage that is cut off, so shorter & softer.

 

[tigdlo]

If you cut a spring, you reduce the whole spring rate by the percentage that is cut off, so shorter & softer.

I'm confident it will be shorter and stiffer the same if you shortened a torsion bar, which a coil spring essentially is.

 

[minimutly]

Ideally you want to know the BMW spring rate which would be measured in kg/mm & can be converted to lb/inch as used by MG.
A quick look at the Brown & Gammons site says MGA front springs come in a range of lengths and spring rates, so decide if it is within the range.
If you cut a spring, you reduce the whole spring rate by the percentage that is cut off, so shorter & softer.

Increase?

 

[bricol]

Yes, cutting the BMW spring will increase the rate compared to its original rate.

If the BMW spring is indeed the same in those measurements quoted, and you keep the same number of coils, accepting it will lift the ride height, then it should be similar in rate - material difference might make a difference though.

I would be bending and grinding - if you don’t locate the bare end correctly in a formed seat, the stress will concentrate half a coil around and it will break - although if you only do limited miles, it might not happen for a good number of years.

 

[Master-of-none]

Increase?

My bad, I misremembered old advice.

 

[addjunkie]

Dont heat the spring, you will probably change the metal properties in the heated area

 

[minimutly]

If you cut it the rate will increase agreed? If you keep all the coils it might be a similar rate but might sit high because it starts out longer. But, more coils need more room, so it might get coil bound on full bump. This is potentially dangerous, if it happens mid corner you might find you take a trip to the scenery...

 

[Matchless]

I think I have found a good solution, the old springs were bent and ground flat both ends, the new springs are bent and ground flat on one end, if I heat, bend and grind the other end it may have a slight risk of cracking but to be honest I don't think that is a big risk, what worried me was that I may need to shorten the springs again once the car is up to full weight, that would mean re cutting, heating and bending for a second or third time, the solution is a Mercedes rear spring rubber cup with a spiral ramp to convert to a flat end, it would then be easy to adjust the spring length.

 

[RWD3M]

Playing devils advocate here, where do you think those BMW springs were made? I doubt it was Germany.

Seriously, for £40 each, just fit the ones from B&G. They aren't going to stock carp. It's an MGA for goodness sake, it deserves better

 

[brightspark]

most of the springs on new cars are krap and break ive had 4 break on newish vans see loads of spring ends bust on the railway crossing where i live . only ever had a leaf spring snap and one coil on old escort vans i had

 

[Matchless]

Playing devils advocate here, where do you think those BMW springs were made? I doubt it was Germany.

Seriously, for £40 each, just fit the ones from B&G. They aren't going to stock carp. It's an MGA for goodness sake, it deserves better

The red springs are from what I seem to remember was an M3 Alpina or similar coilover kit, £1800.00???? we bought the kit for an accident repair and used the shocks etc. they will be good quality, and remember I am a retired tight bugger, anyhow £80.00 for springs, I only paid £100.00 for the whole car!

 

[badabec]

I only paid £100.00 for the whole car!

When was that? 1970?

 

[CompoSimmonite]

When was that? 1970?

In late 70's a colleague asked my opinion if the steering wheel off a MGA was worth anything. Turned out he was fed up of a coupe cluttering up his garage so got scrap man to take it away but for some reason he kept the steering wheel ! Like a lot of cars, at one time they were worthless.

 

[Cobbler]

When was that? 1970?

I bought my MGA in 1973 for £185 & sold it in 1975 for £300 & was very lucky to get it. The person that bought it was stuck with it for a long time. It was a tatty runner & when I sold it it had an MGB engine in with a stage 2 Piper head, it was an absolute flyer & I used it as a tow car for my trials car & trailer, worth sod all though.

 

[Matchless]

When was that? 1970?

1973, paid £10.00 a week............... got it running on 3 cylinders and drove it home 1 mile with no brakes................