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MG MGB GT V8 Factory Originals Technical - Original Buick/Olds starter - problems

Hi
Im running an aluminum nosed Olds 215 starter and it has a hard time turning the motor over quickly enough to fire the car up. Is anyone else using the same starter as I am, and if so, are there starting problems? I tore it down before installation, cleaned the contacts, checked the brushes, lubed the bushings and fitted a new solenoid. My motor is a buick 215 w/ 9.75:1 pistons and block huggers that run close to the starter, too close for a heat shield. Or could it be a battery without enough CCA's? Any help would be appreciated.
Jake

Jake,
I've always run that starter on mine and it will do fine with that CR. However I did have mine rebuilt with high amperage field windings, done by a reputable shop, and have never had any problems with it. There were two starter bodies (field windings) used with that starter, one of which was a larger diameter and produced more torque, but I do not recall if the larger one can be used. If it does fit then that's the one I'm using. The other thing I did was move the mounting bolt holes to rotate the solenoid to a more favorable location. HTH

Jim
Jim Blackwood

Jim
Thanks for the input, I think ill pull it tomorrow and take it up to the local auto electric shop and see what they can do. I checked my battery, it puts out 450 CCA and 525 CA, are these numbers sufficient for the V8 or should I look for a better battery too? Or maybe just a mini hi torque gear reduction unit?
Jake

Jake - before you do - try a second earth strap
RMW

Quite right, I have a heavy (6v) battery lead going from the battery ground to the tailshaft housing of the transmission. Overkill perhaps, but also pretty flawless. A heavy lead to the starter is also a good idea, I used welding cable becaise I couldn't find 6v battery leads that long.

Jim
Jim Blackwood

OK guys, thanks. I know GM apps usually run from the battery ground to the engine/tranny first and then to the body for the lighter amp loads, so Ill try that.
Jake
Jake

Measure the volt-drop while cranking between the hot battery post (not the connector) and the starter hot connection, and the ground battery post and the starter body. Ideally you should only see a tenth of a volt or two in each leg, anything over 1v indicates bad connections that are worth investigating, I have seen as much as 3v total losses in a slow cranker.
Paul Hunt

well, I put in a 4 gage ground cable from the battery to the tail housing of the T5, and the car cranked over faster than it ever has and started right up, even after repeated tries and after it got a little warm it was still cranking like it should. Thanks for the help guys. I also saw that the driveshaft flange to differential flange bolts had all come loose so I'm glad that this came up and I had to take care of it. Thanks again.
Jake

That was fortunate.
That's one ground strap that really should have been done by the factory. It's reasonably short and gets the juice right to where it's needed instead of routing it through the bodywork. It's good you won't have to worry about that. When you get to the show, find Justin and see if he's done that mod, he's having some starter trouble.

Jim
Jim Blackwood

I do have 2 grounds; both 4 ga wires. I've always hated my starter. It has never seemed to have enough juice to crank over my motor (10.5:1 comp) I'm going to get a gear reduction starter this weekend. The only unknown is whether or not it will make it home in a box or under the hood.

Justin
Justin

I see. Well, that does seem to be the preferred upgrade. Easier to fit in as well. Best of luck,
Jim
Jim Blackwood

I have to say that, like almost everything on the MGB, it works perfectly well just as the factory sent it out as long as there are no correctible faults with it. The body is a jolly-sight lower resistance than any cable. If fitting a new cable direct from the battery to the gearbox solved the problem then either the original battery ground strap, or engine/gearbox strap, or their connections were at fault. Personally I'd always much rather fix the real problem than do a work-around.
Paul Hunt

I don't disagree with you at all Paul; getting things to work properly is always better than a work around. In the stereo world I've found that sometimes you have to put things on different ground paths to get them working optimally. I wouldn't doubt it if the same held true for car electrical systems.

The starter I 'was' using was 40+ years old and has been rebuilt probably innumerable times. Sometimes you can't salvage everything.

My new starter works great though. :)

Justin
Justin

"The body is a jolly-sight lower resistance than any cable"-- well, um, not exactly. Copper has lower resistance to electrical current than steel, and so does aluminum. The body does have more mass and arguably more area to conduct the current, but over a given distance the voltage drop through steel will be greater than through copper. A #2 cable 2'-3' long will not have any appreciable voltage drop at cranking currents, nor will the transmission housing. But the juice travels a longer path through the body and two ground leads as well, and has the higher resistance of the steel so the drop through that circuit will be somewhat greater, and the body attachment points are concentrations of current into a thin ring of sheetmetal. These losses just make the direct cable method more efficient. Take the high current directly where it's needed so to speak. The OEM works fine as you said, as long as all is right, but deterioration can and does take it's toll and rust has more resistance than steel.

Jim
Jim Blackwood

Ooooh, that's the sound of a gauntlet hitting the ground if ever I heard one. An ounce of practice being worth a pound of theory I went out and checked mine. I generally reckon on losing about 0.2v from the hot battery post to the solenoid stud on one side, and the same from the ground battery post to the starter body, and sure enough that was what I was getting. But when I measured between the bolt securing the battery ground strap to the body and that securing the engine ground strap to the engine mount it dropped to 0.04v, and that still included a couple of connections. If had wanted to push the probes through the paint to the metal of the battery cage and chassis mount I'm sure it would have been even lower. Whilst copper certainly is of lower resistance than steel per unit cross-sectional area, the cross-sectional area of the body metal has to be many times greater than any practical copper cable one might use to replace it. Whilst one might expect this to give a *lower* volt-drop on the ground side than the hot side it does have four connections to the two of the hot side and things seem to balance out. Or maybe my body is in much better condition than yours ;o)
Paul Hunt

Well, my body's been through a lot so you may be right. And as is often the case we differ yet again on methods, but of course both are valid.

Jim
Jim Blackwood

This thread was discussed between 09/08/2004 and 20/08/2004

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