RCinXS

Changing to distributorless ignition.

My machinist buddy made a one inch thick, fairly tight fitting aluminum plug. (see Pic)

Tight enough that I can't remove it.

But it's not quite air tight.

Wondering how much oil will accumilate at the bottom of the distrubtor housing.

The drain back to the block is right at the bottom.

Might there be a chance that the oil could fill the housing and leak at the machined plug??

If so, I need to find a way to seal it.

Input and opinions welcome!

Mrmerlin

is there a rubber seal in this plug? is it leaking oil ,
not sure of your question or problem

BigAl1

RC, I was just staring at this last night and thinking something like this.

James Bailey

When I used Electromotive 20 plus years ago on a 911 they supplied just such a plug as drawn by Big Al with rubber o-ring....worked great ! You do need the o-ring to seal and the hold down to keep it in place.

Fogey1

<MORE>, please.

RCinXS

Thanks for the replies.

Searched and searched for a normal block off plate.

Couldn't find one with enough reach to be able to bolt it down.

I can not remove the plug he made. It has a bolt in the side. Looks to me as though he drilled a tapped it with the plug in position, so the threads are probably just enough resistence to prevent me from knocking it out from behind.

Used a mirror to look up through the back plate. The plug is all the way down to where the nylon distributor seal would be.

I filled the back plate with parts cleaner an let it sit upside down. It doesn't leak, at least with a thin fluid.

May have been mistaken about it not being air tight.

Looks like he machined the plug to fit where the nylon seal would be and also machined the plug at the top to fit the recess.

As far as I know he remachined the back plate to get perfect fit.

I'll talk to the machinist tomorrow to see if he sealed it.

If not, I'll have to figure out a way to remove it and address the seal.

I guess, if nothing else, I could weld the top of the plug to the back plate.

Still would like to know if there is any real pressure build up in the distributor backplate.

Looks like the oiling for the gears comes from the run off from the bearing. Like the gears sit in a bath of oil rather than being sprayed.

James Bailey

So it is really stuck in there.....

RCinXS

Hi Jim,

Yep. Really and truly a tight fit.

I'll call him tomorrow and explain that I need to add a seal.

I have a hat seal that would fit nicely beneath the plug.

Since the plug is solid, I could drill and tap a hole in the top to put a bolt that might help me pry the plug out.

Before I do anything, I have to talk to him.

Heads are on. Need this resolved, to bolt on the cam towers.

atb

Any chance of getting more? Got an EDIS system going in soon!

Bart-Jan

I've converted my 16v to EDIS and also made a plug similar to yours. In order to be able to remove at some time in the future, I made a blank hole in it and tapped it with M6 or M8 (can't remember). To remove it, simply screw a bolt in and pull. You'll probably be able to drill a hole (be sure not to go all the way through) and tap thread in. The only downside is that it'll probably be difficult to be 100% centered and straight. But than again, it's only needed for removal.

I wouldn't rely on the plug to stay in there just by gravity and friction between the two parts. Some sort of mechanical or chemical fixture would be more reliable. I've made another simple bracket to keep it in place and is fixed in the way the distributor was fixed as well. I'll make pictures tonight.

RCinXS

Great sugestions.

Sliding the engine back in on 6-13-11. Lots of thing still on the to do list.

I'll work on some other parts of the Spring project and will also call the machinist today.

Looking forward to the pix.

Thanks!

Lizard928

I just took the factory distributor and cut it up, then welded a piece of aluminium overtop of the hole.
It uses the factory ring, and hasnt leaked a drop!

RCinXS

Hi Colin,

That's what I was going to do.

The machinist is a buddy of mine and wanted to do something a bit cleaner.

The plug does look real nice. Since he's my buddy, I feel the need to use it.

How to present the problem to him graciously. After all, he's taken the time to help me out, on many custom parts for the project.

All for pizzas and beers.

WallyP

Just mention to your buddy that there usually is some pressure build-up in the 928 crankcase from blow-by, and you are curious as to how he sealed the plug to be air-tight. He may have put an O-ring on the plug...

RCinXS

I like that Wally.

If he didn't. He just might say "Dohhh".