Hi everyone I am putting some NGK Iridium plugs (BPR7EIX) in my 78 308, can anyone give me some advice on what I should gap them, they recommend .025, but I guess it depends on your carburator set up, and fuel to air mixture. Has anyone used these plugs, and if so, how has your experience been. At one time there was a great article on this site, back 3 years ago on spark plugs gapping, not sure were it went. I am starting to get disappointed with fchat, I find it very difficult to find old discussion, that were great, some engine rebuiltd, and clutch replacements, and a whole lot of people doing a lot of neat things, now I cannot find all those older chats, to bad I guess.
I use BP5ES in my 77 and gap them at .025". I also have Pertronix breakerless ignition system. Timing set at 7*BTDC at 1000rpm. I just recently changed them at 5 years and still will use the older plugs as spares or tune up plugs.
I use the NGK irridiums and do gap them. I had never heard anything about not doing it. Just as a note the plugs which I have used 4 or 5 different times vary a great deal in the gap as delivered. As much as regular plugs.
On older cars I wouldnt use the Iridium or platinum plugs. Iridium and platinum foul out much easier, the electode tip is very small. Those plugs are designed to suit Newer High voltage ignitions and precise fuel injection systems. I would use the NGK standard v-power plug. Just my opinion.
You probably won't believe this, but I use Autolite 63's in my '79 308 GTS with great results. They don't foul, they are cheap, readily available, and just as low-tech as my points-type ignition. Also totally reliable and can be gapped as you like. I use stock specs--.025 to .028 or so with excellent results. I used Champion N7Y's but have not been happy with start-ups or longevity.
I'm using BP6ES plugs with the Electromotive system that I installed last year and the car runs great.
Sorry, not true. Platinum/Iridium plugs virtually never foul out if proper heat range is used. 5-10 years is typical life with no maintenance whatsoever. My '72 Dino has stock point ignition. Dinoplex changed out to to Perma-Tune. Stock coil. NGK Platinum ran 50,000 miles. Decided to replace plugs during rebuild even though plugs looked good. Platinum was obselete, only Iridium available. Have 15,000 miles on Iridium and all OK. 0.025-0.030" gap is fine. I use 7 heat range for highway driving. Good luck. John.
Hi everyone, so I changed the plugs this morning, I did place the iridium plugs, and set the gap actually at about .028. I disagree that the iridium plugs do not need to be gapped. I was surprised to find one plug gapped out of the box at about .015, couldn't believe it. Thank god for magnets. I used a magnet to get the spark plugs out of pistons 5-8. Not much room to work on that side. I think I brought the car back to life. The bosch plugs I had in there were in pretty bad shape, I had never changed them since I owned the car. You normally need to redjust your carburetors after you put in wires, and plugs, because of the efficiency in combustion. I never, I basically ran the car this evening, I shut off the car, and pulled out spark plug in piston #1, it looked great, the car is burning rich, which is perfect for these cars. I ended up bleeding the radiator system, and gave the car an oil change also. I took it for a rip, knock on wood, it runs nice. I appreciate everyones advice. Thank you.
+1 the smallness of the gap is to facilitate spark at a lower voltages. Iridium is almost as conductive as copper and much more so than platinum. Andrew
I've used NGK's, Bosche, and all kinds of plugs in my ' 77 GTB. Finally I threw in a set of AC plugs for $1.49 a piece and the car is running the best it ever has run since I bought it. I still want to put in an electronic ignition, and then maybe I'll join the plug wars again. For now, I'm happy with the cheapest plugs in the store. Bob Wassam
I just had issues with poor running in my 81 GTSi below 3500K and just as a test put the Autolites the PO had in the car back again....runs better than the NGKs I have tried...not sure "hi tech" plugs are the way to go myself. I have heard Autolites were pretty common in 308s at one time. The ones the PO had in looked like they were there quite a while and still they run fine.
Check the Manual, that's too much gap... From memory the book says .015 to .025, the engine plate says .025, I have found the sweet spot is actually .022 with an NGK BP5ES.....on my carb cars. No need to go newer tech on those as the ethanol laced gas is devarnishing the whole fuel system, fouling them often if you don't use the upper rev ranges.......... no experience with the iridium, multi prong etc, that's obviously incorrect for a 30 year old system. The spares in the tool bag are Champion, IIRC.......and real rusty!!!
Once they get wet (bad cracked well seals) and 'short' or are damaged by an arcing extender I have never had them come back to life, myself...... There's a test tool you can use on the coils that shows the max gap for a fat spark, JRV used to have one, obviously the condition of the coil itself is a huge factor...once it's weak you'll have no end of troubles...
That'd be some chart! It's really a matter of brand loyalty and no doubt the specified gap varies widely in Ferraris over the years...just read your books. Also in some plugs the numbers are reversed, higher is colder, and others higher is hotter, so that's a good reson to stick with one brand as you trouble shoot.. OEM Champions just rust too fast for me, but I need new well seals! NGK is locally available and cheap enough a set.....it was clear on the carb cars, a warmer range for street use then you went colder on the track to avoid overheating at constant high revs...
All things being equal, an electronic ignition and modern high output coil will allow larger gaps. My book says .025 but I gap mine at .032 and my fouling problem was much improved. Of course I'm just masking a too rich condition, not solving it. Remember, stock carb 308's are old cars with outdated coils and ignition systems. If you've upgraded, it makes sense to me to upgrade the spark plugs (and gaps) as well. Ken
What's an "upgrade"????? LOL! Well, I have fitted MSD epoxy coils but they are still mounted sideways....... EVERYTHING I ever read of the Ferrari OEM oil-filled ones said: "Do not mount sideways".....LOL!
Agreed, I had the Crane Cams XR700 on my carb, 78 308GTS and ran NGK 6's with .034 gap. Running .025 caused a miss.
You're on the money. It also has to do with the reformulated gas having less energy per volume. This got explained to me once by the product manager at NGK, but it's gone in and out of memory. My wife says the same...., but I digress. For Daytonas, for instance, we've found one heat range warmer than stock, the BP6ES work with gaps of .030 to 0.35 work best with CA gas. If you're really going to run it hard, BP7ES, the normal heat range for a Daytona, will also work. I've run them with both. I use the 9 heat range for the GTO and F40. 8 for the TR, 512TR and 512M. 5 for the 166, 6 if running it harder. The NGK BP6ES, 7ES, etc. are only $1.50 or so plug, so they are cheap. The thin wire platinum plugs (DxEV and EVX) were about $3 to $4 a plug. The Iridium jobs another $2 or so more. I didn't notice a difference between the D9EVX and the Iridium plug in the GTO, but the D9EVX is no longer made. I did notice a difference in the BP6ES and Iridium plug in the Daytona. The cheap BP6ES was better. Go figure. Steve
A couple of you have mentioned using Champion plugs. We stopped using them in our racing application when their quality seemed to slip significantly maybe 12 years ago. We went to NGK and are still with them. NGK is a far superior product. Russ
Lotus recommended Champion 7 for the Europa, but no one uses them as "everyone" has fouling problems with them. Ken
I think you guys might want to rethink using the original gap as stated in the manual. Our modern fuels require a larger gap. My manual says .018 to .022, or there abouts and the plugs fouled like crazy when I used that gap. I started using a .030 gap and it runs better with the larger gap. Bob Wassam
