Does anyone know where to get a set of air injection plugs?

Verrel is having them made, and we will be the reseller. Expected delivery date is around Jan 1, IIRK

 

They are based on Steve Magnusson's design, with some minor mods from discussions I recently had with him, see his drawing & pictures in this thread:

http://www.ferrarichat.com/forum/showthread.php?t=189974

They will have short (10mm long) tips, thus will not require removing the header & trimming the tip to the port profile.

Material will be brass which is galvanicly compatible with Al, so won't corrode & sieze up, & isn't subject to galling in Al the way SS is.

Ricambi will have them by the end of the year.

Don't be scared off by the early prices I tossed out in that thread, I've found a machine shop that gave me a significantly better price that I was working with when I made those posts.

 

Will these work if the pipes have rusted off and all is left is the hole in the header? Or is it time to remove the header and get it fixed ?
Thanks in advance

 

You are confusing the air injector plugs with the plugs for the header sampling ports (which is what you need) -- do a search on "110860" (which is the PN for the plug for the header sampling ports) for threads discussing your problem (if the male fitting of the exhaust sampling tube has really disintegrated, you probably will need to drill out/pick out the old bits and chase the theads in the bung with an M12x1.25P tap -- which for the 5-8 bank does probably require removing the exhaust header).

 

Verell -- Actually, 308GTS was asking Rock if the ones that he was offering in this thread had the tip -- but no harm clarifying what you'll be making (but you decided to increase the length of the tip from 8mm up to 10mm?).

Rock's part had that super-extra long tip (that needed to be trimmed before installation on an assembled engine or could be trimmed to match the exhaust port wall shape if you had access to do so) -- but I guess he angered the gods because his posts here, and in that other thread, have been deleted.

 

Steve,
Pls check the dwg you sent me in the other thread. Per the dwg & our eMAIL exchanges, the tip length is 10mm max & desired length(6mm min length only if last piece from bar). Perhaps you're remembering the tip OD which is 8mm max.

From previous threads most people seemed to prefer the 'short tip' style, & those who wanted a 'long tip' solution could go to Rock.

I just noticed that Rock's posts had vanished from the other thread. You're probably right. I'd suggested to him that if he was offering product he ought to at least be a subscribed member, & preferably should have a web site.

 

No, my intent was to say "the nominal tip is 8mm long (1/2 way between the max of 10mm and the min of 6mm), but it could be as short as 6mm if the piece of bar stock you find to make my small order of 24 pieces is a little short". I could've put 8mm +0.5mm -2mm on the drawing, but sometimes the machinist will recalculate the nominal target as 7.25 mm from such a specification. My target for the nominal tip length was/is to be 8mm long (10mm would really protrude unnecessarily into the port).

PS I have to say that putting that big tolerance range on the tip length has caused a lot of confusion for many -- I now wish I just would've put "8.0" on the drawing (and let the tolerance be controlled be the +/- 0.3 mm default tolerance), and not worried about if my Machinist could find a long enough piece of bar stock

 

Steve,
THANKS!!!! for the length clarification. I obviously missunderstood the drawing. I've changed the nose length to 8mm +0.5mm -2mm with a note saying 8mm is the optimal dimension.

I'm sending you an updated .PDF of the CAD drawing I'm planning on sending to my machinist. Any feedback you might have time for would be appreciated.

308GTS,
Sorry, I don't have any & won't until the production run is delivered next month.

 

Verell -- please resend your email -- there was no attached .pdf file.

 

Steve,
Did the .PDF arrive? I did a resend w/the PDF attached almost as I realized I'd failed to attach it(DUH). Couldn't have been more than 1 or 2 minuites after the initial send.

 

308GTS,
It's not a matter of clearing the headers, that's not a problem with any plug length. See the QV air injector picture in post #5 of this thread:
http://www.ferrarichat.com/forum/showthread.php?t=131252
It's a question of making the plug's cylindrical nose just long enough so it pretty close to filling the hole into the port, but doesn't protrude into the port & interfere with exhaust flow. Steve's earlier post in this thread told me that the optimum nose length is 8mm, not the 10mm I'd missread from his drawing.

 

No, I only got one email without the attachment. Could be that my email service has some sort of delay involved, but please resend again -- I can just ignore anything duplicate if it does show up.

 

As Verell said, the issue is making the tip long enough to fill the hole, but not so long that it starts to (needlessly) obstruct the exhaust port. I have no reason to think that the 308-2Vi heads are any different than the 308 carb heads so my drawing in the other thread is my best recommendation of how the plug should be made -- i.e., the nominal distance from the underside of the hex head to the end of the tip should be 18mm (For example, if you are getting some of Rock's pieces cut down -- Rock's part may, or may not, have the same length of the threaded portion so the optimum length of the smaller tip itself on the end may, or may not, be the same as my design -- but the overall length from the underside of the hex head to the end of the tip should be 18 mm).

The header really isn't involved as the plugs go into the cylinder head (as shown in this jpeg) -- not the header:
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Did I mention you can pull the nozzle, cut off the tube and plug the top of the air line fitting with a ball bearing??? LOL!

 

Guys, I'm the fellow who made up some DIY plugs out of my old damaged nozzles.

With the headers removed, I scribed each plug unique to the cylinder for a smooth gas flow.

Here's a couple of different pictures of these plugs, each one specific to a given cylinder.

Point of this post is that if you are going to make a one-size-fits-all plug with a square end, rather than the beveled ends that I used, the straight part should be about 1/2" long per the pictures, rather than the shorter distance as shown in Steve's drawing.

The final picture shows one such plug installed, looking up into the exhaust port. Note that there's no "hole" in the port at the end of the plug due to the bevel (the yellow paint was sprayed in the port so to make the picture easier to see; it's dark in there!)

A minor detail, to be certain, but no reason not to try to make the plug end as unobtrusive as possible to the gas flow.

Cheers - DM
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Steve,
Sent you the .PDF, but then noticed it's BIG (4MB), so sent a .JPG, not as detailed but less than 200KB.

 

Verell -- Got the email with the jpeg, and just sent back my response.

 

No argument with your observations on your particular part set Dave -- I just wish I could remember what I really did My best recollection is that I scaled the drawing shown in Section O of the 308GT4 OM, but I can't recall if I intentionally left it a little short just to be safe if the tolerances all stacked-up the wrong way, nor if/how I used my actual parts (maybe my particular carb head castings were a little different, or they changed things slightly in later years trying to protect the nozzle a bit more and improve the heat transfer). I do recall that my priority at the time was to "protect" the small web of aluminum at the bottom of the hole and keep the hole as clear of carbon build-up as much as possible (because I was switching back to stock every couple of years). I do agree with you that, with a square end, it would be best if it filled the hole as much as possible without protruding.