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Bob yes I noticed the different application too... seems stock there (battery hold down) was a cheesehead - not sure a wingbolt there would be very practical since its very tight quarters for fingers...
I'm keeping my original "wing-bolt" strap bolt on there - because I'm constantly taking it off, and putting it back on. I mean, I don't know what I would do if I couldn't twist it on and off by hand...
I mean really, besides a concours original, do you really need a "wing-bolt" on there? Are we all constantly taking the strap on and off? I think I took mine off once to clean up the strap and body connection when I put a new battery in there.
A simple bolt with a decent sized washer would seem to do the trick nicely as a replacement, and like others have mentioned, would likely provide a more secure connection.
Have we covered all of the possible scenarios yet?
Of course not... alternate option put a battery switch there - sounds like thats what you need anyway - save you some time.
Since I also do a lot of work on my car - the switch is valuable - unbolting the regular bolt is a pain indeed - a wingbolt less but still you have to secure the end of the strap so it can't ground out...
One more alternative: Chinese battery disconnect "switches" just happen to have the correct thread size on there *****. Buy one for ~$4, use the **** and throw the rest away. These switches are designed to attach to a top post battery in series with the battery cable. The **** is a couple of inches in diameter and plastic covered. You can get enough torque with your fingers to get it tight.
One more alternative: Chinese battery disconnect "switches" just happen to have the correct thread size on there *****. Buy one for ~$4, use the **** and throw the rest away.
Thanks Earl, I have a couple of those lying around. I would have never thot to check.
Just tested with some bolts - one fitted to car has a 1/2 imperial head; bolt that fits is 5/16 BSW - 18TPI, same as 5/16 UNC, so ITS NOT METRIC guys.
Start looking afresh .
jp 83 Euro S AT 51k
Do you think it is possible that a PO stripped the threads on the original brass insert that is brazed into the body and repaired it by brazing in a new but imperial insert ? I just can't see Porsche using imperial fittings.
Apart from the brake lines that is.
Why wouldnt they use imperials where the wingbolts are off the shelf items? thats my guess anyway. Many people who use ball bearings just pick the cheapest (=highest volume) suitable size, without caring whether they are metric or Imp. The area in mine doesnt look bodged in any way, black paint in all the right places etc. A more likely scenario would be a stripped thread tapped out to next biggest size, but 5/16 is actually .0625mm smaller than 8mm, so I doubt thats happened. The fact that my bolt head is EXACTLY 1/2" is also a give away to me.
Those of you who have studs and nuts (wing or otherwise) there, please check the size of the nut for and report back, and if a unc nut fits...
jp 83 Euro S AT 51k
I can't imagine where one would buy imperial wingbolts in Germany, they've been Metric for nearly as long as France (Napoleon)
maybe some enterprising soul at Porsche buying department bought new old stock from a defunct British motorbike dealer.
Historic bike specialists is becoming the place to get the more esoteric imperial stuff in the UK, unless there is a thriving aftermarket supply chain for your imperial car (ie Land Rover pre middle 80's ish.)
I just checked my '91 GT and it is M8 1.25. I know an '88 and '94 are the same size. All used 13mm head cap screws before we started using battery *****. Maybe the old wingbolts were a different size?
if it helps, as ball park measurements:
the wings are about 2 inches long.
the bolt is about 1 inch long.
I have my 1980 has M8 with 1.25 pitch.
the above can help in chosing an aftermarket handle/**** substitute for the wingbolt
I replaced mine with an adjusting **** off of your basic office chair. I've tried several different ***** salvaged from "throw away" generic office chairs and, so far, they've all worked. I would, however, suggest shortening the length of the threaded portion to about half - three quarters of an inch - otherwise you're spinning it forever...
Cheap/free fix that works better than OEM. And, if you want to disconnect the battery and isolate it, you can just unscrew the ****, turn it upside down so that the plastic **** is resting on the chassis and slip the hole in the ground strap over the threaded end. No possible short, no draw.
11-18-2007, 12:34 PM
