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MG MGB Technical - MGB Engine to chassis ground cable

I have a 1976 mgb roadster. Every thing I read leads me to believe that there should be an engine to chassis ground cable. However, I have looked and looked and can't find one.

Where should this cable be located on the 76 MGB?
Kurt Valentine 1

Kurt,

Not sure about the 76, but on my 69 it is attached on the engine mount beneath the carbs. It is attached via the bolt system securing the mount, both above and below the rubber block, so allows current flow around that 'insulator'.

Regards
Roger
Roger T

It should be from one of the bell housing bolts to somewhere on the body. We didn't have one on PopTop so I went to Advance and bought one (after I convinced the doofus there that I actually DID know what I wanted - I guess a female in the parts store is suspect).

Ours is grounded to one of the bolts that was already in the engine bay.

TheMiz

Hi Kurt, I have been looking where the groundstrap is on my recently acquired car (58 A with MGB 18V engine). Have not found it yet but I just purchased 'Your Expert Guide to MGB & MGB GT - problems and how to fix them, by Roger Williams. Started reading it a lunchtime today, and, it has a picture of this on page 16 - on early cars the earth (ground) strap loops across the rubber engine mounting at the front of the engine (and is arrowed in the colour picture).The text says that it is 'fron gearbox to chassis rail on later Bs'.

PS. This is my first posting. Hope it helps.

Ted Leis, Washington state.

T Leis

Mine is a 78B. Not sure where it is 'offically' supposed to be but I just have the one across the left hand engine mount as Roger describes. As long as there is a strap somewhere from the engine/gearbox to the body I don't imagine it really matters where it is as long as it can't flex too much.

Simon
Simon Jansen

Kurt, et al. On the 75 and later cars the ground strap is located on the right hand side of the transmission. It is attached to one of the bolts holding the right hand tranny mount (forward bolt) to the transmission cross member (the single bolt holding the tranny mount to the cross member). It seems to be made of braided stainless steel and has an electrical connection at each end with the connector at 90 deg to the long axis of the braid.

Pre-rubber bumper cars did have a ground strap in the engine compartment. My 68 does. But, on the later models look for it on the right side of the tranny to cross member mount.

Les
Les Bengtson

My '66 B came from the factory with two grounding straps (as described by Les). One was at the left engine mount and the other at the left transmission mount.
Steve Buchina

Hi all.

It isn't a bad idea to have two (or even more) earth straps. It is good to have a strap that is long enough to have a loop in it (like a flattened 'omega') as this allows it to flex over it's whole length rather than tending to flex at a single point (usually near the end).

Braid flexes well in one direction, but doesn't do so well when flexed 'sideways' (the strands rub and wear).

I wouldn't have thought that a stainless steel braid would have been a good idea, as most stainless steels are quite hard and brittle, and are relatively poor electrical conductors.

This reminds me of a thought that has been in my mind for a while... the HT currents flow in a circuit, just as any current does, and the earth strap is part of that circuit. Is there any merit in providing an earth strap between the head and the coil to improve the high-frequency characteristics of that circuit ?. Morris Minors had the coil mounted on the engine rather than the chassis, and were always very reliable starters.

Don
Don

This thread was discussed on 07/04/2006

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