Propshaft problem

[Tiger]

Great news trail run gave almost no Propshaft issue.
However very poor ability to climb the smallest hill.
Seems over geared in top
We are on 450 tyres at the moment is there much advantage changing to 400

[David Stepney]

Sounds a bit if your engine is down on power. The Mk2 Ruby was the most powerful of the standard cars, with (as I recall) 17.5 bhp and the car that I knew some years ago would almost reach 60 mph given enough road. The rolling radius difference between 400 x 17 and 4.50 x 17 tyres give only a difference of 18 revolutions per mile (809 as against 785) so there would be no discernible difference.

Are your brakes correctly adjusted so that they are perfectly free when off?

[David Stepney]

Tiger, as an addendum to my previous post I note that, some time ago, you mentioned that your car came with the earlier low compression head and that you were minded to retain it for the time being. I presume, however, that the rest of the engine will be the later three bearing engine.

The most usual cause of poor performance, all things being equal, is timing too retarded. Your car should be fitted withthe later Lucas DK4 distributor, which has automatic advance using bob weights and, when in good condition gives about 16 degrees of advance (at the crankshaft). I would therefore suggest that you initially set the static timing to top dead centre and go from there. The cars with the earlier head will tolerate a little more advance; my RP is set to 20 degrees maximum advance, which equates to about 1 9/16 in on the flywheel rim. If the car still feels 'flat' with the static timing at TDC, I would advance it little by little. You will know if you have too much advance, as the engine will start to sound rough and growly.

Hope this helps.

[Tiger]

David
Thanks for your input.
My engine is exactly as you remember(you must have a great memory because it’s some time ago I mentioned the cylinder head). Must be the Welsh air !
However as you know it’s difficult to be sure of any A7 spec.
I have some doubts about the distributors advance /retard ability (DK4)
Next distributor off and examine
Also and perhaps before, I am doing try to mark the CS pulley to use a stroboscope ?
Tune in for the next instalment
Regards
Tim

[David Stepney]

It's not that my memory is good, Tiger, it's just that, before I put my post up, I did a bit of research to make sure I was not going to give you any incorrect advice, and came across one of your posts that mentioned that you had the earlier cylinder head.

There are a number of threads on this forum that deal with problems arising with the DK4 distributor, mostly centering on weak bob weight springs and worn pivots, which restrict the amount of advance. I understand that some of the bits are obtainable from such specialists as Distributor Doctor or the like.

Checking the timing with a strobe is a good idea. At least you can see what is going on as you rev the engine.

[Ivor Hawkins]

I used a three bearing Ruby motor with a low compression head for years and it was one of the sweetest Seven engines I ever had. I used the DK4 distributor as well and it would climb any hill, though it was in a lighter body.

[Tiger]

Distributor advance system looks DODGY
All loose so after alot of failed attempts to find advance springs I telephoned the distributor doctor.
Very helpful chap so new springs in the post.
So will will see !