Rob Edwards

I recently re-plated a bunch of parts including an oil pressure sensor that appears to have survived the ordeal. So I am now going to replate another engine's worth of bits, including 4 FPR's and 2 dampers (or is it 4 dampers and 2 FPR's? anyway...) The trick is protecting the inner guts during plating. The vacuum connection is easy, I have some silicone cpas used for powdercoating (an post the size if anyone cares...)
The threaded fittings on an FPR are M16 x 1.5, which is the fine thread pitch for M16 stuff. I cannot find M16x1.5 acorn nuts, and the only thing I could come up with was M16 x 1.5 nuts and some short bolts. Total cost is $6 per FPR (3 bolts, 3 nuts). Anyone got a more elegant solution or source for big *** acorn nuts? I can't find any car lugnuts in that size, maybe some big german truck somewhere?

Here's the current solution on a just bead-blasted FPR: (I'll add some PFTE tape to better seal during plating):

Thoughts?

worf928

Hmmm.....

Plastic cap nuts?

http://www.componentforce.co.uk/en/i...tcategory&id=7

BTW, what kind of plating are you doing? Chromated zinc? Or something else?

dr bob

Rob--

There's usually enough room to plate the threads without risking bind-up with the nuts. Check and see how tight they are, maybe with a thousanth or two for new metal space. If that works, use the silicone plugs that the powder-painters use and plug the ports. Ditto the vacuum connection-- use a silicone plug instead of a cap and the outside of the nipple will be correct with no plating seam. Are you replating the metal fuel lines and the nuts? Might want to mask the inside threads on the nuts if you can. Depends on how much slop there is in the threads. If that turns into a big issue, attach the fuel lines to the regulators/dampers and plate them together, with the other ends of the lines plugged where needed.

I'd rather be doing what you are doing today. It's garage door maintenance day: a little sanding, some stain touch-up, a few coats of new varnish. Car is outside drying its little black measels where touch-up was done. Should be ready to shave and finish by the time the bottom panels on the door are done. A monster's work is never done...

Rob Edwards

Dave-

Great idea- I sent for some samples but am not sure I want to buy 5000 of these caps...

Bob- I think the threads were plated originally but I'm covering them while beading to avoid getting beads in the FPR's (which will ultimately migrate either into the injector nozzles or into the cylinders.....) I'm not confident that a silicone plug would stay in place during plating though perhaps the process is more gentle than I think. I know Tony had some FPR's re-plated and haven't heard him mention them having been blown up or ruined.

PS- Move to a stucco McBox like mine and you will have more time to obsess over more important stuff like sealing FPR's for replating. You guys still headed to VCR in the AM?

worf928

Ouch. Well, I'll help ya out. I'll buy 100 of em.

Actually, I'll bet that we could find a distributor that'd sell to us if we were only buying a couple hundred.

dr bob

Rob--

The silicone plugs are amazingly durable. Maybe some HD rubber stoppers from your lab? Use them for plugging the ports and have a blast on the threads. If you are concerned about them getting loose, drill a small hole real close to the big end, and safety-wire them or tie-wrap them together around but not touching the FPR body.

Leon Speed

Rob, can you please share what you wound up using for the fuel parts, dampers, FPR, fuel rails, hard lines?

Hilton

I recently plated my fpr and dampeners - I used a few of the caps that come on new receiver driers for the 928 AC system. They have the same thread plus they have a rubber o-ring which ensured none of the (corrosive) plating solution got inside to damage the diaphragm. I also stuck a piece of tissue paper inside first so I could be sure it stayed dry on my test part (an 86 fpr).

For the barbs I used tight silicone vacuum caps.

Jadz928

Interesting stuff! I saw smaller QTY purchases here: http://www.stockcap.com/

Fabio421

The problem I see is that you are trying to cap off a fluid connection with a bolt/nut. Go to a hydraulic supply store, the larger the better, and have them sell you some hydraulic caps. They may need to order them since they are metric.

danglerb

Maybe get a few sets of these Thexton plugs?

http://www.tooltopia.com/thexton-312.aspx

I think I have a couple sets and maybe left one with Greg if you want a test fit.

NoVector

Based on the inside of my FPD that I discovered last week, I think coating the inside would be a good thing! Don't know if it's common for them to rust on the inside. I'm guessing air was getting in through the diaphragm(?) Anyway, new one on the way from Sir Tyson. The thought of that crap going to the injectors sucks...

Leon Speed

Thanks for the info all!

danglerb

The catch with coating them inside is that while shiny, they don't work anymore.

Looks like you had water in the system.