Lowering a Minor - Torsion Bars - Marina?

[Oddball67]

I'm considering lowering my Minor and just wanted to know how best to go about it, any problems I may incurr and/or, should I consider fitting the Marina Torsion bars because they're meant to be thicke?But are they a straight swap?

I read somewhere that Marina LCV's one's are the best to fit but a) they're pretty rare now-a-days and, b) you have to conduct some modifications to them.

As usual, your help and assistance would be appreciated.

[bmcecosse]

Marina bars are not a straight swop - need special brackets at the rear and I don't think available now - and can you find Marina bars anyway?? Limited lowering possible at the front or you will simply hammer the bump stops through the inner wings....... And lowering the front unfortunately throws even more +ve camber on the wheels - so even worse handling....... Biggest improvement is to add -ve camber with a thick washer behind the eyebolts, and put more viscous oil in the dampers......

[IslipMinor]

Do you want to lower, stiffen, or lower and stiffen?

Lowering is achieved by adjusting the rear reaction arm on the crosmember end of the torsion bar. Depending on where the arm is bolted through the 5 step adjuster bracket, you can get up to about 1" lowering if all the steps are available. Jack the car up so that the suspension drops on to the rebound stop, make secure with axle stands and with care you can lever the end of the reaction arm down so that the bolt can be removed and the bracket slid along to get the next level or maximum amount of lowering, before replacing and tightening the adjuster bolt. Check the tightness after the car is back on the ground.

For more than is available from the adjuster bracket, you will need to take the load off the suspension and torsion bar, slide the rear reaction arm forward and move it 1 spline upwards, looking from the side of the car, slide it back into position, and using the same position in the 5 step plate, you will get ~1 1/4" lowering.

For stiffening, Marina/Ital torsion bars can be fitted, the van being a bit stiffer than the car. They need to be shortened by about 3/8" with an angle grinder and a special adaptor used at the crossmember end. Owen Burton used to sell them, and ESM, who do many of the OB parts, have chosen not to do the adaptor, so that would make it a bit difficult to fit them without it.

The Morris MInor Centre in Birmingham list uprated torsion bars at 50%, 75% or 100% at ~£300 per pair including VAT and delivery.

I would suggest trying just lowering, with some thicker oil in the front and rear dampers, SAE30, (assuming you have the standard lever arm ones?) and as Roy suggests, you will need to space out the front eye bolt to correct the camber geometry that goes positive as you lower. Further benefit is that as you space out the eye bolt, the wheel end of the suspension arm comes forward very slightly, increasing the castor angle and improving the 'turn in'.

If you are going to remove the suspension to space out the eye bolt, then fit polyurethene bushes everywhere before refitting it.

Doing this altogether will make the car very much better to drive!

[bmcecosse]

Anyone know if the 'uprated' T bars are of heavier section - or are they just heat treated and more heavily stressed! ??

[chrisryder]

it's achieved by diameter.

[bmcecosse]

But - presumably they must reduce to the original sizes at the two ends - which must put tremendous strain in the metal section there......

[chrisryder]

i recall that standard bars are normally smaller than the ends, which then increase in diameter at the ends to get to the spline size. the larger diameter bars just reduce the 'step' but are still smaller than (or possibly up to the same size as) the splined ends.

[minor_hickup]

But - presumably they must reduce to the original sizes at the two ends - which must put tremendous strain in the metal section there......

Why would they reduce to the original sizes. They would have to be a monstrous diameter to need to taper down at each end. My 100% uprated set are the same diameter all the way along. The originals have a taper about an inch from the splined section and then are much thinner than the uprated bars.

[bmcecosse]

They would reduce if larger diameter - but it's been explained that the diameter remains less than the splines, but larger than standard. My concern really was that the standard steel bars had just been 'heat treated' to increase the spring rate... Clearly (and reassuringly) this is not the case.

[charlie_morris_minor]

I can confirm that the diameter of the upradted bars is indeed greater than the standard one but still less than the diameter of the splines..

acording to JLH the 100% uprated ones can be a bit harsh on anything other than smooth roads.. which i read after i purchased mine.. so i will be able to tell you eventually when I get my car back on the road.