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doctorbob
United Kingdom
145 Posts |
 Posted - 20/03/2014 : 15:51:16
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A simple question, do the bolts that hold the C type chassis together have the nuts on the inside or the outside of the chassis rails?
Cheers Bob |
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O.Thomas
United Kingdom
755 Posts |
Posted - 20/03/2014 : 16:07:35
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| Outside!! |
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doctorbob
United Kingdom
145 Posts |
Posted - 20/03/2014 : 16:23:43
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| Cheers! |
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tholden
United Kingdom
1638 Posts |
Posted - 20/03/2014 : 17:59:35
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...and should be drilled and split pinned with castle nuts.
TH |
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Hamish McNinch
United Kingdom
110 Posts |
Posted - 20/03/2014 : 22:41:56
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| Why? |
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tholden
United Kingdom
1638 Posts |
Posted - 21/03/2014 : 09:49:25
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OK Hamish...and should be drilled and split pinned with castle nuts if you want to do them as they were done originally..
TH |
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Hamish McNinch
United Kingdom
110 Posts |
Posted - 21/03/2014 : 10:41:47
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| I didn't realise you were there at the time, Terry. You don't look old enough!! |
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Simon Johnston
United Kingdom
6131 Posts |
Posted - 21/03/2014 : 10:57:15
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quote:
Originally posted by Hamish McNinch
Why?
Might it have something to do with ease of access? Presumably the bolts would have been drilled after the castle nuts were tightened up and that might be hard to do with the nuts on the inside of the chassis rather than the outside. Just a thought!
Simon J
J3437 |
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tholden
United Kingdom
1638 Posts |
Posted - 21/03/2014 : 11:35:02
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Thanks for the compliment Hamish.
I can only say that the old boy I used to know at Mann Egerton told me his first job at the factory was reaming the holes and split pinning the C type chassis and said how boring it was. Colin Tieche tells me that every bolt on 0276 was so fitted and on page 21 of Maintaining the Breed John Thornley says " Cars to this specification wired and split pinned in every hole and in all aspects prepared and ready for the track, were offered for ....."
I accept they may not have all been done like that and with todays smooth tracks, Loctite or locking nuts will do the job just as well but I think there was a good chance that the factory did them like that.
Simon bit difficult to drill them after the nuts are fitted.
TH |
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Simon Johnston
United Kingdom
6131 Posts |
Posted - 21/03/2014 : 12:04:17
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When I were a lad I remember working on a 4 1/2 litre Bentley crankcase where the castle nuts and studs were individually numbered to ensure they matched and the holes in the studs had been drilled to suit each individual nut when correctly tightened. Tedious to do, but possible as the hole doesn't need to be larger than the gap in the castellations of the nut. Of course once dismantled the effectiveness of this would be lost if the bolts/studs and nuts were reused. This sort of careful attention to detail would probaly be more relevant in an engine assembly than a chassis of course.
But back to the original query of why are the nuts on the outside, if it isn't for access to drill them individually, is there another reason?
Simon J
J3437 |
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tholden
United Kingdom
1638 Posts |
Posted - 21/03/2014 : 12:21:29
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Simon a lot but not all of the J chassis bolts were fitted with the nuts on the outside as well. The bolts holding the front knuckles, the front engine cross tube, the brake pedal mount and the rear chassis bolt were all like this but items fitted later such as the firewall mounting brackets, brake cable mounts and wings stays had the heads of the bolts on the outside.
Maybe when the basic chassis was assembled it was easier and quicker to fit the nuts on the outside.
TH |
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Hamish McNinch
United Kingdom
110 Posts |
Posted - 21/03/2014 : 14:25:27
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| I reckon ease of access would probably determine. And once the mechanics had had their first go they would have put them back in whichever way suited them best!I have no doubt Terry's old mate at Mann Egerton recalled correctly - certainly it's a boring and tedious job to do properlyly! And it very rarely is. The two advantages of bolts over rivets is that they are easier to get undone if something needs replacing and you can check they are tight on a regular basis - all good things on a car that is used properly. If you drill and pin them, you really ought to replace with new every time to repeat the operation because it will never be tight in the same place. The tendency is either to back them off or tighten them up to align with a slot each time - and either way has problems obviously. I think originality has its limitations. |
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tholden
United Kingdom
1638 Posts |
Posted - 21/03/2014 : 15:00:47
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I agree with you Hamish.
I guess most people tighten or torque up the nut, mark the bolt then align that in a jig for drilling. As you say that may be all right first time around but on re-tightening you seldom get correct alignment. To solve this an old engineer once taught me to pop the nut in the lathe and remove a few thou from the underside to achieve alignment. It sounds a bit hit and miss but actually you soon get the feel of how much to remove and it works well.
Probably not one for the purist engineer who would I am sure advice replacement of both nut and bolt - an expensive option these days !
TH |
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Simon Johnston
United Kingdom
6131 Posts |
Posted - 21/03/2014 : 16:12:51
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All pure speculation of course, but how about the nuts being on the outside simply to make it easy to visually check that they were properly split pinned? And I guess on the chassis it would have been easy enough just to pull the nut up a bit tighter to align the holes for the split pin rather than either drill them in situ (which is possible but tedious) or remove them to drill them on the bench (equally tedious I would have thought).
It's well seen we've nothing better to do on a Friday evening (well it's evening in the Caucasus!)
Simon J
J3437 |
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Foz
United Kingdom
769 Posts |
Posted - 21/03/2014 : 21:32:57
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maybe it was a youth employment scheme.....was not the young apprentice called Bathingtowell given the job on the C chassis assembly and broke all the drills so when they got to the D-types had no choice but to rivet them ...
Foz |
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