What do you think it's purpose is?

Not original VW or Speedie conversion part.  Do you have a rear engine mount (cross bar) --- they are rare on stock engines.  Or could it be an exhaust support bracket.  I can't see where it hits body - appears its in the rear engine cooling tin see circled are - ignore note.

I took another look at lunch today. There is a cut out in the rear engine cover plate for the crankshaft pulley. The hole is covered by another plate (under the engine cover plate) with a well formed into it to allow for the depth of the pulley. So it looks like it's just a protective plate for the crankshaft pulley and to prevent debris from getting into the engine compartment. 

Well, I looked at Wolfgang's drawing and since it doesn't have part numbers to identify, I got lost.  I have that same sheet metal off of my engine right now, so here goes:

Those two "bolt" locations are to secure the rear engine apron to the engine breastplate (the tin piece just behind the v-belt pulley).  There are supposed to be two, 4mm X 1.25 pitch screws where you show them:  about 4" to the left of the edge of the pulley, and about 2" to the right of the pulley.  If they are loose or plain not there, the tin may vibrate or buzz at certain engine rpm's.  

Often, they get over-tightened or rust out and get stripped out.  The only salvage left to most people is to drill out the captive nut below the bottom tin (the breast plate) and run a bolt through them.

So here's the deal:  Go buy Two (you might as well do both) 1/4" X 20 bolts 1" long (1-1/2" if the tin's captive nut is still there but drilled out), four 1/4" fender washers (you may get away with a regular 1/4" washer if the holes aren't too big) and two 1/4X20 "Nylok - Nylon Insert" - Stop Nuts.  Put one washer under the head of the bolt and insert into the hole, then another washer under the tin and then the stop nut.  Run the nut up til it's nicely tight (feel good resistance, then another 1/4-turn).

Remember:  Getting them "as tight as I can make it" caused the captive nuts to fail in the first place, so just enough in the tightening department.

There is no rubber washer involved, but if you could find a couple roughly the same size as the washers you use (check the plumbing department) and put one between the tin and the bottom fender washer it might make things quieter - shouldn't need it, but what the heck.....Won't hurt, either.

The small metal piece below the second 'd" in "needed" is often missing (think only used in '70 up models).  It covers the main pulley nut. I bought a kit of button head SS screws with washers to replace all the tin screws.  You use a hex driver to install them.  Only $16 shipped.

http://www.thesamba.com/vw/cla...etail.php?id=1384319

Thanks Guys for the great responses. Gordon, the sound I've been hearing is exactly like tin and it only occurs (or I can only hear it) at various RPMs. And Wolfgang, I think I'll go ahead and the kit. I'm sure there are a few other bolts missing. 

thanks again

The large washer/bolt combination on the passenger side appears to be for blocking off where the stock breather hose would go and now helps keep exhaust heat out. The drivers side should not need that large a washer. That lower piece for the crank pulley also helps keep out exhaust heat.

Nope.

The breather hose hole is tucked in close in the corner between the fan shroud and the generator pedestal.  The hole shown is 3"-4" farther to the (car) rear and is where the screw goes to old the apron to the breastplate.  Trust me.......I've been cleaning and painting those exact parts for two days, now, getting them ready to go back on my engine.

This pic shows the breastplate, the slot/hole for the breather hose next to the dipstick tube and the screw hole in question in the foreground on the right, and the second hole (that he has to fill) just to the left of the pulley (mine has the captive nut in place).

Yes, my breastplate is a little beat up.  Serves it right for pissing me off....

Gordon, you are a man after my own heart. Beer in Carlisle just for showing this picture and making me feel, just slightly, like less of a knucklehead.

Yeah, and if you're astute you might notice that big, 3/8" vertical gap near the dipstick tube between the cylinder tin and the sled tin covering the bottom.  The sleds are original VW, the upper tins from China.  Guess which one was 3/8" too short?  I ended up custom-making an aluminum spacer to fill the gap, back when I built the engine in the '90's.  

The last of my engine tin is now painted, so I've moved on to new cans of paint and primer and am now sanding out the heat shields - painting those later today.  I have to paint them outside which wouldn't be too bad except for the 40-50mph gusts out there today.  

Remember when I had leaking wheel cylinders a few weeks ago?  Don't know wassup with those, but I got new cylinders from Aircooled and, sure enough, broke off one of the steel brake lines at the wheel cylinder fitting when trying to remove the leaker.  

I know....I shoulda tried to remove them before I hit "send" on my order weeks ago, but figured, "they're only 16 years old and live indoors (but 50 feet from salt water) - HOW BAD CAN THEY BE?"

Well now I find out that on a VW IRS rear end the steel brake lines are about 38cm (15") long.  Everybody in the parts world sells 8" and 12" and then there's a big jump to 20" long.  I actually found an old guy at a local CarQuest who looked at it and said: "Oh!  That looks like an old VW Beetle brake line - There aren't any of those cars left anymore so we don't stock 'em."

Nuts.  

Gordon,

Can that 20" be modified to 15"...or can the 20" line be installed with an 'S' curve without being shortened? 

I S-curved one on my car a couple years back. Bought a flaring tool this year but I don't think either it or I am/is good enough to do a decent brake line double flare.

It's a form fitted tube.  A 15" (38cm) will fit nicely, anything more or less will either not fit or look hokey.  And my flaring tools don't do bubble ends.

Looks like I'll have to do an online order.....

Gordon, try these guys, right down the road in Hartford......

https://www.bugcity.com/shop/s...0a6120EDA5yXF276AA6A

Click on "600" for brakes and scroll through all the metal lines are there.

The scene of my "Dave's not here!" story!