Who makes really good plug extenders?

Hi Birdman,

I've seen two or three brands of spark plug extenders for 308s, and with one of them the clip inside that goes onto the spark plug is larger and on the other the clip is smaller.

The larger clip gets closer to the perimeter of the extender than the smaller clip does, allowing for a greater likelihood of arcing. The wire of the larger clip isn't any thicker than that of the smaller clip; it's just a slightly larger clip in how it's bent around.

When I bought my car, it had the larger clip style; they were a bit older (but had fewer than 10k miles per the service history), and on my first long trip a few of them actually started misfiring from arcing. They burned tiny little pinholes that you could hardly see or not see at all. They were red or terra cotta colored (I forget), and it was only with very close inspection that I could see evidence of arcing; had they been black, I would probably not have seen it.

The faulty extenders had a logo on them made of stylized letters; I can't remember what it was, but it was something like MAIER [again, not certain] -- I just remember that one of the letters looked like an S but was really an I or something to that effect. I think it was a five letter word with the middle letter very stylized, but again not sure. Point is, in ordering new extenders, I set out to avoid those.

Anyway, a friend of mine had recently bought new extenders from the Ferrari parts people in Columbus, Ohio, and those extenders had the smaller inside clips, so I bought a set of those. My logic is that the more space those clips need to jump across, the less likely they will be to arc. So far I have gone 8k miles without any issues. Car is a 1980 GTBi, FWIW.

I hope this makes sense and is helpful; sorry I can't remember better!


- Tony

 

Birdman, you might try getting rid of them altogether.

http://www.ferrarichat.com/forum/showthread.php?t=261548

 

what is this the season of the witch?

i just replaced mine in hopes they would cure a running stutter.

i purchased them from gt parts in phoneix. 623-780-2200, ask for daniel kunsman.

you might also pm fastradio and get his opinion.

 

I think the ones TONY K was speaking of were MAFER. The F inthe word was much larger than the rest of the letters. I replaced them with the extenders with smaller clips inside and the car runs great. They have been in the car for a week so I can't tell you how long they will last. For 13.95 each, I can change them when they need it.

Hope this helps,
Steve

 

From my experience they are ALL JUNK.

Got a No-Name "small-clip" one that lasted all of 20 minutes. Cracked from the tip, half way down. The ones mentioned above (Maser/Mafer, whatever) are not any better.

Just keep replacing them (the bad ones) until you get a good set of 8. May take 10 or 12 to get a good set but when you do they will last for quite some time.

The quality of our parts has been headed down for quite some time.






Dave Helms, YOU listening?

 

I think this is really the answer.

I have a set of these Accel 7914 wires but need access to a lathe to turn down the ends. For now, they're holding down a shelf. Essentially, this solution eliminates the need for the extenders by allowing you to plug the wire directly to the plug. Someone (who?) needs to make a spark plug end like this that is the correct length for our cars.

 

Look at Kingsborne. I have a set I bought a few years back and they still look like new.

 

Just FYI, Im the guy who did this mod and I've had no problems with them at all with a few hundered miles on the car. THe biggest issue is to save as much wire as possible while modifing the Accell 7914 set. They are pretty close to the right length out of the box. Routing them for best cosmetic issue takes a little time but not too bad. I could only get yellow but I think they come in black, blue, red and yellow? But you have to be very patient and careful when turning them down on the lathe. All in all... its the best mod Ive done on the car since I got it. I still have my 8 extenders on the wall display! lol Joe

 

There has to be a better solution here...

I would agree that the extenders with the larger clips tend to burn through more and promote arcing to the head - have replaced mine (which were the larger clip variety) with the smaller clip version and I don't see any signs of arcing. The larger clip version tends to arc right at the clip end where it gets closest to the head.

I was thinking about trying some plug ends/extenders from an air cooled 911. The 911 has a similar configuration...namely, a deep-set plug...and there doesn't seem to be any problems with arcing. The original Beru 911 wires do have stainless braid shielding with the shielding grounded onto a valve cover stud - perhaps this helps? In any case, worth a try, and I'll give it a whirl.

 

+1

Jonathan,

I've been running my Electromotive for over 10 years w/o extenders. It was recommended that I do this by the race shop that installed it (I think I also verified it with Electromotive).

Henry

 

I've been using NGK extenders, rubber sealed at either end, with no problems whatsoever. They are cheap and they last.

 

Any part number on those?

I was looking at using MSD boots which are almost long enough, and then machining up a collar of sorts that would lock on to the top lip of the MSD boot and extend out the plug hole with a feature for someone's fingures to get around to grab it ... still use the factory seals or I could make it like an umbrella with an o-ring but I don't think that's necessary.

If you guys get real tired of the plug extenders you could just switch over to coil on plugs .

cheers

 

I like the Honda/Accel setup also but I like making my own wires ... looks like something is special about the end connector that goes on the plug perhaps to lock into the extender. I wonder if a standard MSD end would work.

There's also come Chrysler Hemi setups that look like they'd work ... a 2 piece deal with a short rubber boot in the end of an extension that could be easily trimmed and then use the factory water seal.

 

Birdman,

When I got the Electromotive from Nick, it came with a Taylor wire set. The wires went directly to the plugs with a collar that went on the wire and acted like an extender. But no separate extender. I liked that, as it eliminated one additional connection (wire to extender) and brought the shielded wire all the way to the plugs. I simply slipped the plug hole caps over the wire before installing the ends, and the whole thing worked fine. Nothing like a direct connection, coil to plug.

You might want to check out that Taylor wire set as an alternative. Worked great for me on the '78.

Steve

 

How about a pic of that setup? That collar sounds like what I wanted to do with MSD boots but if it's already done great! The collars were a Taylor part or something Nick has made?

cheers

 

I don't have the car anymore, so I can't take pictures of the wires. The only pics I have are with them installed, which just look like regular plug wires. Sorry.

The collars were a Taylor part. The wires were red, and the "collar" as I call it was a black rubber/silicon sleeve that went onto the wire, just about the same length as the extenders. The sleeve was tight and hard to get on, took a lot of silicone spray to slide them onto the wire. Then had to install the clip to the end of the wire that connects to the plug, and slide the sleeve down over the clip. It was a bit of a PITA to do this, but once done, the wires worked really well. I found it easy to connect them to the plugs, and then just slide the caps down to cover the spark plug holes. And they have a molded end piece that snaps onto the posts on the coils and looks good. I'll see if I have a pic of the final setup to show you.

 

Sorry, don't have a part number, all I know is that they are from some Merc application, 123 series IIRC.

 

I bought some extenders from Kingsborne Wire Werks at http://www.kingsbornewires.com.
The are the WSP-4813 Ferrari Spark Plug Extenders for $10.50.

The failure mode on my original extenders was "punch through" of the high voltage in roughly the middle of the extender right at a casting mark. it could be seen in the running engine by sliding the plug boot cover up the wire and looking for the arc. The arc also makes a distinct "tick" sound. I replaced one bad unit but within a year has done all 8. With the black plastic of the extenders and even knowing about where the pinhole is it is hard to see. Maybe it would be easier with red plastic ones.

 

I have a set from Dennis McCann's www.allferraripart.com red ones, PN 116613 and they've been fine for 3+ years now.