Twin Plug Accesories

[alphie]

I've done some searching here but haven't found very much.

What's the deal for machining lower valve covers for twin plugging? Is this a machine shop only task? Is there a template I can give my machinist?

Where can you buy the little metal tabs that hold the plug wires down for the lower valve covers?

And finally, can someone recommend a source for wires? I'm using EDIS (two coil packs) with EFI.

Thanks,

-Rob

[cgarr]

You really dont need a template, just get them close, I could give you the measurements, I used a mill but you could even do it with just a hole saw and file. I dont use the metal clips but if you want them just get some spring steel, (banding Strap) and make some. Wires are easy, get some bulk wire, crimp on some m3 ends and screw the stock boots on them from an old set of wires, that way you can make them all a custom length to fit perfect..

[Quicksilver]

I would expect a machinist who is setup to correctly machine the heads would have the setup to do the valve covers without blinking an eye.

If they haven't done this before I would send the whole job to someone who has done a lot of twinplug conversions and who knows all of the little details. The combustion chamber isn't a good place to let a machinist experiment on your dime. For example: If you have exposed threads you can get preignition.

If the machinist can't deal with the whole job I would box it up and send it to Ollies in Santa Ana, CA. I believe the current price is still less then $300 and that includes the valve covers.

[alphie]

Henry Schmidt did my twin plugging on the heads.

Speaking of which I noticed an issue when putting a set of plugs on the lower side of the heads. I found that there was no way a plug tool could be inserted without hitting the barrel nuts. There was only about 1mm of clearance between the top of the barrel nut and the socket part of the plug.

I ended up grinding a bit off the barrel nut, a convace bit at the top, and I ended up grinding the porsche spark plug tool to reduce the clearance. I finally got it right so the tool could get past the barrel nut. I imagine if I was using different head studs with different non-barrel nuts this wouldn't be an issue.

Has anyone else had this problem???

[randywebb]

Must be someone experienced in E. Canada. If not, is it a big deal to ship them to the NE US?

Defintiely agree re experience...

[cgarr]

Barrel nut clearance problems can be solved by using 12mm plugs.

[syncroid]

Originally posted by alphie
Henry Schmidt did my twin plugging on the heads.

Speaking of which I noticed an issue when putting a set of plugs on the lower side of the heads. I found that there was no way a plug tool could be inserted without hitting the barrel nuts. There was only about 1mm of clearance between the top of the barrel nut and the socket part of the plug.

I ended up grinding a bit off the barrel nut, a convace bit at the top, and I ended up grinding the porsche spark plug tool to reduce the clearance. I finally got it right so the tool could get past the barrel nut. I imagine if I was using different head studs with different non-barrel nuts this wouldn't be an issue.

Has anyone else had this problem???

I had the same problem getting my spark plugs and socket past the head nuts when I did my twin plug engine. I ended up beveling the offending barrel nuts. When I go in there on my next service I will be replacing them with the 993 head nuts.

[Jeff Alton]

Mine fit fine with 14mm plugs, but I am using ARP headstuds and nuts.

I can email you some detailed pics of the covers if you want, Lance did mine.

Oh, and you let the cat out of the bag in regards to who did NOT chamfer your heads....

Cheers