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TR2/3/3A ground strap on a tr3

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sp53

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Could some please post a picture of the location for the ground strap on a tr3? I used to have it on my old server. Thanks
 
Here's how I did mine:

TR3Battery.jpg


O'Reilly's (and no doubt others) sell a braided ground strap. If the firewall is thoroughly painted you will want to scrape the area around the bolt hole clean of paint, a star washer will also improve contact.

The other ground strap is the one from the body to the engine block -- generally from the left hand engine mount to a bolt on the timing chain cover.
 
Mine is similar but I think I got my braided strap at Tractor Supply Co.
 
Here's a nice photo of the upper end from Don Elliott:


And a not-so-nice photo where you can almost make out the lower end
 
This brings up something I've been pondering for a while. My car came with a "modern" sheathed cable attached to the positive ground side of battery and running to the engine block, mounted at the coil bracket bolt. I knew this was not original, but it works. I know the concern with the ground cable was to provide a substantial ground for the starter, which this configuration accomplishes. I haven't changed it over, because it worked and there were more pressing issues up to this point. Is there anything I am losing by just leaving it this way....other than originality points. All electicals work fine.
 
I would look at it this way. The engine and transmission sit on rubber mounts, so what is needed is a ground wirer/strap to go from the engine to the frame or the trans to frame so that the running gear is not isolated from the ground of the battery which usually grounds so the body tub. Perhaps with your configuration the lights, gas gauge, and wiper would ground through the choke cable which connects the engine to the body. I think you need a better ground.
 
Kleykamp said:
...Is there anything I am losing by just leaving it this way...
Click to expand...

I suppose that depends on whether you still have the above-mentioned ground cable from the timing cover to the left motor mount.

If that is in place then I see no serious problem with your set-up other than it looks wrong - but if something looked wrong on my engine and was so easy to set right I would not leave it that way.
 
Efficient grounds have been the bane of all LBCs. For sidescreen TRs, the fuel gauge wins. As Geo Hahn says, get it done but don't make it obvious. Moss has the strap you're looking for (736-040) Even though it isn't exactly right for a sidescreen TR, it fits and can't be seen by a judge. It is what I installed & it fit fine, engine side left motor mount to frame side left motor mount.
Frank
 
I too have a black ground cable that comes from the battery down to the engine/trans. I put it there on purpose. I don't find it looks bad at all. I do have the ground strap near the mounts, but I think my bolt/nut with star washer lug provides a more secure grounding point. I know it's not 'correct', but it's my car, it works fine and few notice it's 'wrong'. I think the important thing is that the battery is 'earthed' as well as the generator/engine/accessories.
 
It’s not easy to get a picture. The two above are about as good as it gets. Geo is the only one I know who may have a better one. Geo...you out there?
 
LBC's and grounding should be as big or larger than supply cable. and tided to motor and frame and body. Body to frame may have poor contact to common ground. Some electoral ground to body ( lights ) others to frame ( horn ) The TR 6 ground has a braided cable with two mountings to motor and body very clean at firewall. NOT OEM on TR 3 but clean. Madflyer

I was at an aircraft sale and there was a British cargo plane with Lucas elect. I think grounding was the best place for it. sorry UK
 
Madflyer: will the TR6 ground strap work on a TR3? I’ve been asking around, but no answer
 
The strap from the frame to the motor?

If it is long enough and the bolt holes are the correct size I would think any braided strap should work.

David
 
Mine uses one bolt trans to motor and one bolt at firewall and battery cut off. Grounding is first thing then clean look any braided strap. ROCKAUTO web has braided cables for a start. Madflyer
 
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