Quote:
Originally Posted by Geoff
Sirrotica,
I am quoting from real world experience, started when I rebuilt my first engine in 1965.......& am still doing it today.
Anybody who doesn't read books to enhance their knowledge base is a fool.
I studied electirical engineering for a total of 6 yrears at a technical college.
Getting back to the frame issue.
Using the frame for grd return is a good idea, has lower resistance PROVIDED the cable connections at each end are clean & have good surface area contact.
Here is something else not mentioned. Starter cable is made of stranded copper wire. Many strands. There is an air gap between each strand. I couldn't find any battery cable for this comparison, so I used domestic power cable. It was stranded, 7 strands; I stripped the insulation off & measured the od with a micrometer: 0.102". Measured the OD of a strand, calculated the area & multiplied by 7. Combined area came to 0.073". A big drop from 102. The same principle applies to batt cable. you might strip the insulation & measure it at 5/16". But it would have the SAME resistrance as a piece of solid copper of a much smaller OD. Steel frame is solid, no air gaps, whsat you see is what you get....
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Spoken like a true engineer, how did I predict that was your background? Simply by your attitude. I bet you love Lucas electrical systems too. The Brits do have a way to make wiring in an automobile as frustrating as it could possibly be.
There's a joke that goes along with Lucas electrical systems. Why do the British drink warm beer? Because they have Lucas refrigerators...............LOL
As I said previously you want to make something simple hard, and you ASSUME it's going to work out in real life just the way it's laid out in a classroom, or in a technical manual.
I went round and round with an engineer about an overheating 4-53 Detroit, did all his suggestions, and listened to his calculations. I told him my opinion was the transmission cooler in the radiator was overcoming the heat rejection ability of the radiator, causing the overheating of the engine coolant. I suggested an auxiliary transmission cooler. I got the same answer you gave me "NOPE". A year later after installing the largest custom made radiator that would physically fit in the machine, reversing the fan pitch, ruining the rings in the engine from continual overheating, and having to have the engine rebuilt under warranty, they tried an auxiliary transmission cooler, and it solved the overheating problem, the first thing I suggested to the engineer a year earlier. By this time the customer was disgusted, bought another machine that didn't overheat and the Gradall company lost their ass in wasted money because their engineer said on paper. "it can't overheat".
We have different weather in the US than you have, we have a lot of corrosion problems with wiring and electrical systems, the OP said that 20 some years ago the car worked with a frame ground, but now it doesn't. Your answer was maybe his engine is to tight, really that's your summation of his problem, and how he should solve it?
Believe me when I tell you that I tried your way in my own car, and until I ran a dedicated ground the engine would spin slowly when everything is heat soaked. It didn't work for me, and there have been numerous people on this board that have had the same problem when relocating a battery to the rear.
I did some due diligence about remote batteries, yes it required reading so you can retract your comment about reading.
Seems there are people split roughly 50/50 about using frames versus dedicated grounds. Some interesting facts that I found, that even though a frame/body ground will work without a dedicated ground, 2 drawbacks show up. The motor components have a reduced life with frame grounds, and there is electronic interference with onboard electronics. ECMs and stereo systems were among the most mentioned systems not getting along with frame grounds with remote batteries. While some people were able to get adequate function from a frame ground, the motors ran hotter, and gave up sooner than with a dedicated ground.
One thing you mentioned previously was tinning all the connection points. You intend to get under the car and tin each connection point where the cables attach to the frame, you must have way more time to screw with an electrical system than most people do. Would you be doing this to prove your frame grounds work. or just to save $50 on buying a ground cable?
Electric winch manufacturers used to ground their units through the winch cases, but due to the high amp draw stopped using a frame ground in favor of a dedicated ground cable. Warn was one of the manufactures that now supply's ground cables to reach the battery terminals, before they just supplied ground straps. An electric recovery winch also draws huge amounts of current, in case you're not familiar with them. The winches draw is likely equivalent to a heat soaked Pontiac starter. The winch draw is around 450 amps on average loaded heavily.
To sum it all up you can make all your tinned connections and screw with short ground straps connected to the frame, or spend $50 for some cable for a dedicated ground with 2 connections, and extend the starter motor life. You'll also be safeguarding any electronics that may not play well with frame ground connections. It's the OPs choice how he'd like to attack and solve his problem.
I suspect you'll have a laundry list tomorrow of why the frame ground is superior, engineers have a lot of pride and tenacity, but I've said my peace.
I'm going to get some sleep Geoff, it's 2:30 AM in Ohio.