Hello ferrari chatters. I have just replaced my plug extenders. I bought qv replacements from Superformance. My problem was that my old extenders are 100mm long and the new ones are 107-108mm long. This leaves my leads not sealing around the lip on the cam cover. I phoned Superformance and they tell me that 2 valve extenders are 100mm long. My car is definatly a qv, so whats going on here? Is their some qv's that took 2v extenders? Is their any difference other than length between the 2v and 4v extenders?Your help would be much appreciated. Dean NZ
It has been many years since I replaced my extenders, but what I recall is that the QV extenders are a few millimeters shorter than the 328 extenders. I suspect the one you have are for 328's. Superformance is probably using the longer ones for both models now. I use the 328's on my QV because they don't have any resistance. The shorter QV units tended to open up (hi resistance) and cause a miss. I have a handful of the shorter QV units on hand if you cant find the shorter units and decide you want to keep them (PM me). The longer units require a little work to get the boot cover to fit over the valve cover hole, but they will.
Thanks for that. Superformance did say that the 328 extenders were a couple of mm longer but not 7-8mm... I dont seem to be able to work the lead down over the cam lip, I may get it down a couple of mm but will pop off after a drive.my old extenders allowed me to fully cover the cam lip and also the lead would press down a further few mm. Its possable my originalls are also incorrect in length. Does anybody know the original 308 extender length?
Hmmm, Interesting. So i wonder why they sell us the longer extenders (328)when the 2v extenders are the same length(100mm) as 308 originals. Maybe they have a different resistance.....
Don't get me wrong, I like Superformance but it seems like much of the stuff I get from them is "almost" perfect, just not quite. The last item was distributor caps. Half of the bores for the leads were not deep enough to allow the connector needles to catch end of the lead. I had to take a drill to them. Shouldn't have to do that with a new part.
Superformance doesn't know a Ferrari from a Ford, and many of their parts are cheap repros that they sell at massive margins. Look out when you return items ... they conveniently "forget" to credit your card.
Time to get rid of those pesky extenders. I did so many years ago on my 85QV US model and I live in California with strict smog inspection and passed easiliy. See attached and you can basically replace extenders and complete set of wires for about $150. I never tried attaching a pdf file to this site but hopefully it works Joe
Wow thats a much better way Joe. I wish I had gone down that road before I spent such a fortune on new leads and extenders. Thanks for the pics.
You're welcome Tonksy1. A lot of f chatters have already done this and no more worries about defective extenders. The extenders were like an extension cord for your home appliance which is not good. Ferrari changed their design later on and eliminated the extenders and have a setup similar to mine. Your car should run smoother, no misfiring, and startup easier. Joe
Thanks Joe, was about to email but I guess you worked out the pdf thing Anything to change for a 78 carb? My boots are different but that shouldn't present a problem.
Not too familiar with your 78 carb. Maybe the WSP-C737C part on my diagram might be a different length for your car?? You could order one WSP-C737C and try it out. The last time I purchased seven years ago, they were $2 a piece.
You got the wrong ones! Send them back and get the correct ones. I just replaced all 8 on my 83qv, they were the exact same length and color as the ones that came off. Not a problem with the boots fitting down in the spark plug tubes and sealing as they should.
The extender design is to provide better heat protection than bare wires. Superformance replacements work well, with a large cost savings. $500 spark plug wires are good for a chuckle. If you must have the original CAVIS wire, you can get it from the good folks at Midwest Bayless. Low cost ($35) aftermarket wire, E.g. Accel, works just fine. There's an excellent post on rebuilding 328 wire assemblies here: http://www.ferrarichat.com/forum/threads/ignition-lead-rebuild.428411/
