Thread: Lifted P38 on air - questions

17 thou = .4318mm

Of which .48mm is listed as a medium drive interference fit for pipes 18-30mm in the engineers Black book.

So, I suppose it should fit - just.

[Thanks for that. The 0.817" o.d. bung is only available with a 5/8" thread. I'm going to pursue a 3/4" jack screw thread - which makes things a little more difficult.

I'd have to drill out the front panhard rod using a 59/64" (0.922" or 23.4mm) drill bit to accept the smallest size weldable bung that has a 3/4" thread.

I'm not sure I'd be able to drill that diameter at home. It'd need a lathe I suppose. But how would you mount it? With a drill bit in the chuck?

The option of welding a socket over the o.d. of the panhard rod then becomes the favoured option. Problem is I can't find anything to suit, off the shelf. The 30.3mm o.d. is a funny size. I can't identify it from any tubing schedules. Hence why I've enquired with the ebay seller linked above - they appear to have a machine shop that makes the required sockets, albeit at a different diameter to the one required.


QUOTE=benji;2066824]17 thou = .4318mm

Of which .48mm is listed as a medium drive interference fit for pipes 18-30mm in the engineers Black book.

So, I suppose it should fit - just.[/QUOTE]

Would it be simpler to turn the bung down?
I'd fit in a lathe easier, and it'd retain the strength of the rod.

Dont think you can. You'd end up cutting too much meat off the bung. At 19mm thread, you'd have to get the od of the bung down to 20.3mm.

With a 5/8 thread you get away with it. In fact there are bungs available to suit that need no turning. But is 5/8" enough for the jack screw.

I've had a reply from the ebay seller - ill post it asap. They're recommending a press fit (plus welding) over rod approach, allowing the screw to run inside the panhard rod.

Reply from the ebay seller, who's selling the panhard rod jack screw kits (see link in piror post):

Dear davidsonsm,

hi sean
ah, I wish it were as easy as you describe. maybe I should appoint you as project manager for these, you'll probably do a much better job than I do - haha.
but of interest, is that we use UK made nuts.

well we probably should make them for the P38+ and the good news is that being hollow tube, of the right internal dimensions, we can make them so that the screw retracts into the rod. a design that we use on most other models, only the rovers and one other local car have solid rods.

we actually make the press fit to a very close dimension, so I would need to acquire a sample so we can get them to press fit onto the od perfectly.

yes we can make them. however, right at the moment we have production tied-up making engine mounts. it will probably be about 4 weeks before I could look at making the parts.
are you able to wait that long?

cheers
robert

My thinking for the front is to thread the panhard rod. Rear, with bungs welded in. Given most of the problem appears to be the rear rubbing on the chassis rail I feel priority should be put to the rear bar. All been well I should catch up my engineering mate tomorrow. I'll take the bars with me for his opinion.

Gary

To thread the id of the front rod would involve shrink fitting a sleeve I'd imagine. Because at 20.3mm plus threading, what jack screw could you use?

Very interested to hear a professionals opinion. All good stuff. I'm reluctant to take any meat off the 5mm wall thickness, unless it can be reinforced with an insert.

A7/8 UNF if one can be found.