Remember those hot Splitfire plugs I showed you back in a previous post, they were clean and white like new, even after 250 miles. Well, I put my old Autolites back in, with the nice lightbrown coloring. Will this help in keeping the engine running cooler, or is some change in the engine keeping the plugs cleaner? Currently, I am just swapping them out to test them. Still need to buy that Edelbrock Metering Rod set, but have to wait til next payday.
if you want to use the splitfire you probably need to jet up a few sizes. at least until you see some color. if you can't get any color i'd stay with the original plugs. and if it is burning lean it will run hotter.
I put the old light brown plugs back in today, but got sidetracked (found some new bucket seats, can't wait to install...) and never got a chance to test drive it. Hope it cools down a bit.
Got to drive the mav today with the old plugs. I drove about 15 miles, and idled in the garage for about 20 minutes while I made adjustments on a newly installed 2" carb spacer. Had to adjust the throttle, because with the 2" rise, the throttle was open to 2500 RPM with my foot off the gas. Anyway, highway drive for about 10 miles at 70 (3250RPM) and city drive about 5 miles, and never got above 180. Actually stayed right below 180 the entire time. I am happy with that. The plugs raised my running temp about 15-20 degrees. Also, air temp was low 80s, so I guess there are too many variables to verify that temp drop.
Surprising that the plugs would make that much of a difference. I wish I could find some colder plugs to run but never can find any. I'm running the large plugs in the early 351W heads clint
I checked the plugs today, and they are still light brown, but not as brown as before. I may be just cooking the old brown off. Still running lean, and need that metering kit.
I've always heard that it's extremely hard to read plugs with todays gas. Also always heard you need to have new plugs to read them and to read them after a hard launch like at the track but to shut it down without idleing it. I read somewhere that the splitfires were bad about the tips,being so small getting too hot and causing pre-ignition. I've heard alot but know nothing. lol clint
I actually liked the splitfires, for the couple hundred miles I used them. I will put them back in when I get the metering rods and get the mixture correct. I used the .040 gap that came stock with the splits, and since it worked so well with the new coil, I re-gapped the old plugs with .040. I hear that will heat things up a bit also. But, I figure that since I get a bigger longer spark with the better coil, I ought to use it. Might try .044 later. but got to get the mixture right first.
Ran it hard today, 4000 rpm at 90-ish mph. It stayed at 185 degrees. Even at idle. 86 degrees and humid on this beautiful south Texas Memorial Day! Can you say "summer"? I need another beer....
Scott, could you feel if the car ran a 'little' better at higher rpm's with the spacer? It might take a trip to the track to compare against last week's numbers to know for sure (but then again, the air temp/barometer/humidity/etc would have to be close to the numbers on your last trip)/
It may be all in my head, but it felt like it took off better, and ran better at higher rpms. I like the performance over all rpms above 1000. Idles like crap until warm, but once it warms up, it just kinda lopes a little, actually sounds good. But until I get to 170 degrees, I either have to keep the choke on or rev it periodically to keep it from dying. I will make some adjustments and fix this. So far, very happy with the spacer.
