MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - Firewall holes

Bill Chasser and I are having a discussion about where the ground wire goes on the left side of the firewall.

Chris Coopers firewall diagram has more holes listed than I have on my 1950 TD, one being what he has marked as ground on the left side.

https://www.mg-cars.org.uk/mgtd/mgtd_firewall.htm

I believe on my TD the ground went to the coil bolt.

I know there would be more holes on the later TD's with the separate fuse block, but do some of you that have early TD's have a picture of your firewall?

This would be a good point to clarify.




Bruce Cunha

Bruce,

Have a look at this from Chris Cooper's gallery.

They are pictures from an Unrestored 1951 MGTD (11272).

https://www.mg-cars.org.uk/mgtd/Pictures/TD11272/Thumbnails/mgtd_gallery_thm_TD11272.htm

Picture #68 shows the car to have a 5-contact regulator and separate fuseholder.

Picture #159 shows the left-side ground wire being connected to the firewall via the coil bolt.

This is the same arrangement used in my car, built November 1951.

cheers,
David
David Padgett

David, Thanks for looking that up. That is exactly how my 50 TD is set up.

So where or when did the hole that Chris's firewall picture labeled "Harness Ground" come in? (I also do not have the small hole next to the ground for the oil line. Mine goes through the battery box in the hole marked there as oil line.

https://www.mg-cars.org.uk/mgtd/mgtd_firewall.htm
Bruce Cunha

Bruce,

No idea when the 'Harness Ground' hole was introduced. My car doesn't have it either.

However, I do have the 'oil gauge pipe fitting' hole. It is used to mount the pipe/flex tube adapter to the firewall.

Also, from another scan of Chris Couper's excellent gallery, I found the following picture #56 from the 'Assorted Unrestored Pictures' group, and have included it below. (Thanks to Chris Couper). Unfortunately, we can't see the car number.

It shows an above view of the area of interest of the firewall but with some components removed.

The 'Harness Ground' bolt with ground cable fitted to it is in the red circle. The yellow arrows show the coil attachment holes. The green circle surrounds the 'oil gauge pipe fitting'.






David Padgett

Here's the TD 1250 bulkhead Bruce. I did add the opening for a temp gauge line to run to the radiator.




L E D LaVerne

Excellent, so again we show production changes not otherwise listed. Sometime after TD 11565 in 1951, they added three holes. One for the oil pipe connection, one for the ground harness, and one for the oil pipe.

I looked through Clausager's list of production changes and I did not see any that would seem to need the new holes.

It may have just been an observation by the production crew that putting these on the coil bolts was not as tidy.
Bruce Cunha

In looking a bit more. My guess is the holes were added when the oil pressure/temperature gauge was added.

February 1952 TD 13914.
Bruce Cunha

Interesting point Bruce, though I wouldn't have thought that 'tidiness' with regard to wiring in this area would be at the top of the list.

In fact the provision of an extra nut, washer and bolt, just for the ground connection, would certainly not adhere to modern manufacturing practices which demand savings by optimum and minimal usage of components.

Maybe they just had a few extra bolts on hand?
David Padgett

I wonder what the parts list shows? Sometimes that's the best source for changes. They often list a chassis/engine number for a part if there is a change.
Christopher Couper

In further discussion and evaluation, it is clear that one of the holes was added to move the oil line bracket from the battery box to below the coil.

I am unsure if MG moved the oil line off the head to the block (I know users have), and moving the bracket was needed due to the length of the oil line.
Bruce Cunha

Bruce,

Yes, another question with debatable answers perhaps!

I figure it must have been MG's decision to move the oil gauge line from the head to the lower block, based on the following.

The WSM shows the 'oil gauge line to head connection' in the exploded view of Engine Components, Page A2(WSM Issue 2). This is the only indication in the WSM showing the oil gauge line coming from the head.

However, Figures A1(Issue 4) and A35(Issue 2) each indicate the oil line connected to the gallery rear end, lower block. Also Fig.P1(Issue 4) shows pictorially the flexible oil line appearing from beside the coil (after coming thru the battery box)and dropping down to the block gallery, as above.

These figures are all from the same copy of the WSM which is obviously a consolidation of a number of Issues released at different times.

Also, I believe there are a number of other threads relating to the pros/cons of each of the two connection locations.

David
David Padgett

Interesting find. Most of those are artists renditions.

Look at Drawing A 30, A 33m and A 34. Again renditions, but they clearly show the banjo bolt on the head, not the threaded hose fitting.

Bruce Cunha

Chris Couper's picture #56 shown in David Padgett's post is of my car TD 23004.
Joe
Joe Olson

This thread was discussed between 20/10/2020 and 24/10/2020

MG TD TF 1500 index

This thread is from the archives. Join the live MG TD TF 1500 BBS now