I have a 540 with Comp cam, MSD 6-AL box and MSD 8207 coil. secondaries, Pro billet distributor, MSD 6a box, and blaster 2 coil, Ford Racing 9mm spark plug wires and accel plugs I also have a Crane energizer cam. Make sure the ignition switch is in the Off position. plug gap 555, I'm not an MSD fan anymore, what with their pieces being made in China now, and I run a 25+ yr old setup with a Ford Duraspark dizzy, Taylor wires, Jacobs #8 computer and 380672 coil, and run the gap at .080. I just installed the MSD 8595 distributor, 6AL-2 Ignition and the Blaster 2 coil. The cam is a CBXR280R-10. Spark plugs seem like a simple component and it can be believed that a hotter plug is always the best choice when in reality too hot of a plug can be very harmful to the engine. This is why we recommend you stay away from the so-called âhype plugsâ. However, we do recommend following the engine builder or manufacturerâs specification for spark plugs. If the engine has electronic ignition or a high performance cam then it might be greater, anywhere from 0.45 to 0.60â³. 4,213 Posts . For example, with an HEI system, you must have a coil and module that is strong enough to jump a wider gap. The motor is a 390fe .030 over 9.0:1 compression, RPM Performer heads and intake, 750 holley vac. MSD judges the plug gap by compression and components: We are also aware that using the MSD with platinum plugs may increase the chances of pinging and detonating. I just want to get some feedback on what everyone thinks the best spark plug is? As mentioned a spark plug operates in the range temperature 450 â 870°C, at 450°C carbon deposits being to burn off and if a plug may have a very black insulator nose at a lower temperature. A proprietary ceramic material enhances the dielectric strength of the plug housing forcing the spark, even under extreme cylinder pressures, to jump across the plug gap to the ground electrode,â MSD â¦ Typically, plug gaps are dependant on ignition. Within the bounds of the ign system. White Wire Trigger: If you are using the White wire (points or electronic amplifier) of the MSD to trigger the ignition, follow these steps. I've searched about the same thing, HEI GM plug gap and .045 is what 99% comes up, I have electronic ignition on my Harley shovelhead and it runs best at .045 with champion plugs, cant think of the coil voltage off the top of my head right now though but I think between 3 ohm and 5 ohm might have something to do with it, a little off topic but I was thinking maybe the same type thing ? Itâs important to have a quality spark plug for the best performance, since there are so many combinations and manufacturers, MSD does not recommend any specific gap. 6. ok well here's the deal. The gap of the plugs can be opened in 0.005" increments, then tested until the best performance is obtained. The traditional spark plug uses a "J-strap" design for the electrode that extends over the tip of the plug. I was running NGK Iridium plugs (Part # WR5IX) before. It is recommended to follow the engine builder or manufacturer's specification for spark plugs. The silicone jackets of the spark plugs provide extreme resistance against heat and the so does the straight boots of the unit. What spark plug gap 07-20-06 04:19 PM - Post# 971900 In response to murfs66 Plug gap size is dependent upon how strong your ignition system is. I was seeing everyone saying that they gapped their plugs at like .040 or .050 Where my stock gap is .034. should i be enlarging my gap also or is this for a different type of setup not pertaining to my equipment In plug lingo, the A-engine used standard plugs and the Magnum used a resistor-type plug. Right now I'm running number 2 heat range AC rapid fire plugs. The MSD box will fire a $ .99 cent plug with the exact same intensity that it uses to fire a $6.00 plug. Personally, on gas I run an NGK cold v-type plug at 0.9 with MSD and a bosch coil (the little black transformer type). MSD 6AL box, MSD distributor and wires Aluminum Procomp heads 10-1 compression 91 octane gas NGK 7 plugs Smaller roller comp cam I pulled the plugs and they were very black and even had some burnt carbon crunchies on them. I read one Chevrolet mechanic that gaps his plugs at 0.42â³ in small block 350 engines. MSD summed up for us on their educational site what is exactly happening within the ignition process: A typical (meaning stock) 12-volt automotive ignition system operates by taking in a low voltage with high current from the carâs battery and changing it into a higher voltage with lower current to jump the spark plug gap to propagate combustion in the cylinder. Wider gaps can be used with certain high-energy electronic ignition systems. The wires feature 500 ohms per foot of resistance for improved spark delivery and power, with a helically wound conductor that suppresses EMI. Find MSD Street Fire Spark Plug Wire Sets and get Free Shipping on Orders Over $99 at Summit Racing! Spark plug gap and MSD I am running a MSD Pro billet ready to run. âThe center tip of the plug is made from iridium to promote the best spark and increase resilience. Discussion Starter â¢ #1 â¢ Apr 29, 2006. Spark plug gap for Points is .035 and any electronic or MSD is .040-.045 General Guideline- Pump gas street engines would use a -5 to -7 heat range, high compression race engines may use a -8 or -9 heat range, and boosted/nitrous engines may use a -9 or -10 heat range depending on levels of boost/nitrous. A high-performance engine responds to an increase in plug gap because the wider gap produces a more energetic and powerful spark. Re: New HEI for 70's built 350. Checking The MSD Ignition For Spark. I wasn't sure what to gap my spark plugs when I put them in. Rufas just to know that most of what you and Dave are discussing is over my understanding. of the spark plug boots, MSD offers Pro-Heat Boot Guard, PN 3412. Other tips include running a tighter gap, since high cylinder pressures place much greater demands on the ignition system. While spark plug gap does not have a direct effect on timing, excessive gap in a power adder application can easily cause engine misfire. I have a lot of experience with the MSD on street trucks and cars. The MSD can fire some pretty big gaps, but it really depends on how good of condition the high voltage side of your ignition system is. Close the gap, and you get a longer 'cold' spark. Yes, .080. The cranking history has been very good in past. Spark Plugs: Choosing the correct spark plug design and heat range is important when trying to get the best performance possible. You want to run as BIG as you possibly can before expeirencing misfiring. Since there are so many engine combinations and manufacturers, MSD does not recommend which plug or gap is exactly right for your application. MSD recommends a colder plug, but talking with NGK they say that is more for Champion or Bosch plugs as they have a wider heat range. Magnum plugs use a gap of .040 inch. Plug life isn't what it could be, but plugs are cheap. The tests for the upgraded HEI were with 0.055 plug gaps. we suggest the use of the MSD spark plug wires PN# 31199. MSD's spark plugs are engineered to improve the efficiency of the combustion process to create the most power possible combined with increased durability. I just installed a new msd 6A MSD kit in my 1968 el camino. The NGK 6619 Iridium IX Spark Plugs snags the top pick in our spark plug comparison because they offer the best mix of high-performance, fuel efficiency, durability, and dependability. Stock gap on the 87-93's is 0.052-0.056" SO the gap the shop gave you sounds right for an N/A car. If you have a coil that can fire a strong spark through the gap (they can), then it will contribute to a better, more consistent ignition of whatever is in the chamber. Its a stock 302 with e7 heads, carburated, e-cam, long tube headers, x-pipe, holley 650 d.p., MSD 6-AL box, 16* timing, and the cam gear is advanced. So I when with what was on the MSD box for the compression. Probably 0.35â³ for a carbureted engine. The center tip of the plug is made from iridium to promote the best spark and increase resilience. I do have a problem with a question about spark plug gap. If you get the Davis Unified Ignition for AMC which is basically a souped up HEI, they recommend .055-.060. I was wondering what was the best spark plug i should go with and the size gapping on my car. The Bosch [ Australia ] HEI system specified 0.065" plug gaps on engines with well over 9:1 CR. The Performance Distributors coil and module equipped unit was good for a solid 9,200 rpm (Performance Distributors claim 9,000). I'm going to upgrade the ignition even more with new 8.5 msd spark plug wires. MSD Street Fire spark plug wire sets deliver high performance at value prices. At 870°C a spark plug will have a very white insulator nose which will blister if this temperature is exceeded and the ground electrode will melt. Common sense tells me that the greater the plug gap, the greater exposure the mixture gets to the heat of the spark, the heat in the spark being what ignites the mixture. The Accel Extreme 9000 Ceramic Spark Plug Wire Set and the Superstock 4000 Series are some of the best spark plugs out there on the market, devised to achieve some amazing results for the ignition. Magnums use one plug. The gap makes a difference (in theory.....). Gap. The following test will determine if your MSD is producing a spark. With that, you can then experiment with the plug gap to obtain the best performance. I checked the gap and it was set at .028" which seems small. Every Ignition Has Two Sides. Remember, a spark will jump the path of least resistance, which could be a bad plug wire, or a carbon tracked cap or rotor. A-engine plugs use a basic gap of .035 inch. The bigger the gap, the more power required to jump the gap, hence the spark ends up 'hotter' but shorter. The reason is the bigger the gap, the larger the spark and the better chance of igniting all of the air/fuel mixture. No misfires, EVER, hot, cold ,lean, rich, whatever.