Talk Morgan Forums Morgan Sports Cars Morgan Plus Four, Supersport & Plus Six (CX & CXV Generation Vehicles) Ground clearance on the Plus Four

As I found over the past fortnight, the broad traffic tables are fine because entry and exit are shallow; it's the smaller ones with a sharper exit that can tickle the belly.

John
With our Plus Six (would also work on the Plus Four) we welded a SS muffler protector plate on the front and rear so that should we hit a speed bump etc. the muffler will ride up rather than be ripped off. Apparently some cars have such a fitment as standard.

With your dropping suspension I'll be very interested in hearing what KH have to say. According to both Williams and Melvyn Rutter none of their other owners have had this problem with the Plus Six and we were told to contact MMC.

Kerry

Good evening Chaps,
Krazy Horse have raised the rear of the car by following the advice they were given by the factory for Plus Sixes. Namely to lift the car so the wheels are hanging, slacken the wishbone, I think to chassis, attachment, which lowers those fittings. Tighten them up again and take the car off the lift. Please excuse my non-technical and therefore possibly mistaken recollection of what they said.

I can however confirm the following ground to inner edge of wheelarch measurements:
... Original........Home from KH......Now (following a 66 mile journey)
R OS......627...............667..............645
R NS......634...............663..............648

So the car is now more level side to side with an average 16mm additional ground clearance.

I'm off to Dorset for a couple of days on Wednesday so will report back then.

Best regards,
John

Nice easy fix John. I would imagine during build the cars are set up with a template or fixed measurement but possibly this doesn't adequately take into account the settling in of springs over time.

John
I certainly interested in what happens after a trip to your ride heights on the Plus Four.

When we came to dropping the suspension on the Plus Six to fit the SSL replacement coil over damper suspension units we found that the suspension must have been assembled in the Morgan with one person on one side and another on the other as the bolts were overtightened on one side and almost loose on the other side! I think all that KH has done is to release all the suspension bolts then torque them all up to the same tension. So within the limits of hand-made wings your heights should be the same on both sides

BUT I doubt if they will remain at an increased height. I get more height you have to either put spacers under the spring platforms, or fit replacement units with adjustable spring platforms.

Many years ago I was looking into building a kitcar.....Lotus7
Reading build manuals revealed tips on setting up the suspension. It was recommended to assemble the 4 corners but not tighten bolts fully until after engine fitment as that extra weight affected settings. Build a rolling chassis, fit engine ( and some other parts) then torque the 4 corners up. The reasoning being the car is at a ride height specification with final load weights.
Do MMC do this ? It’s been a while since a visit but are they tightening up the four corners before fitting heavy parts? The added weight could be reducing ride height after tightening. What is the MMC chassis build assembly instruction for the order/ method/ checks?
Should it be.....
Assemble and fit suspension torqued to a preset initial torque.
Fit engine, tank, other specified parts.
re-torque suspension and check ride height.
This ride height might be slightly different to the final fully built car one to allow for the extra weight of body, trim etc. So a couple of mm higher at the rolling chassis stage, this being removed by weight of everything added later.
Basically have a process for assembly that results in the correct end result.
If there are issues with faulty/ sub standard components such as weak wrongly heat treated springs then that is a separate issue. Mind you it might show up during the build. Is there a sampling/ test regime for spring deflection, for example? A simple test jig?

With the Trads, a red marker pen was used on all fittings once tightened. If that practice continues with the CX cars, it will be possible to see at what stage the suspension components are torqued up on a factory tour.

Chaps,
An update on the ride height of my Plus 4.

Measurements in MM from ground to inner edge of the wheel arch

The rear o/s was 627, after KH adjustment 667, a few days later 645 and today (27/10) it is 630

The rear n/s was 634, after KH adjustment 663, a few days later 648 and today (27/10) it is 640

The car has been driven mostly solo which may account for the o/s being lower but that being said it is disappointing to find that I am more or less back to where I started.

I'm off to the Lakes for a couple of weeks tomorrow loaded with two people and lots of luggage so I will report back after that. In the meantime I would be interested to hear other people's experiences.

Best regards,

John

Have you checked your tyre pressures ?

We will be interested to hear the results but it is a concern that it dropped so much so quickly.