Spark plugs

Discussion in 'Small Block Tech' started by maseusmc, Apr 10, 2015.

  1. maseusmc

    maseusmc Gunny G

    I check with you guys for everything from under the hood to the brake lights. I'm about to check my spark plugs because I'm being told by my mechanic friend that the engine could be flood. I replaced the starter & alternator and now the Lark is back firing from the carburetor. ( at least my buddy said it was ) So my plan is to remove the spark plugs. So my question, is the spark plug gap @0.035 or 0.032? Which is a good reliable brand that cost between 5-10 bucks?
  2. alec296

    alec296 i need another buick

    AC delco stock ones are fine. You could go with ac rapid fires or NGK(Alittle more $) but I would consider a points conversion . but you should figure out the " backfire" first. If plugs are right heat range and spark is good with proper timing it should not flood. Your friends advice isn't completely accurate. Its not going to flood if everything is working properly. Even with wrong plugs. Flooding will show a problem somewhere.
  3. chris 430

    chris 430 Member

    Hey guys ur5 good for hei 430 block
  4. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    The AC Delco plug is R43S. They are 1.46/ea over at Gap is .035.

    Replacing the starter and alternator should not cause your engine to back fire. If the engine still has points, check the point dwell first and adjust. Then check timing. Make sure you connected all the wires involved in starter and alternator replacement correctly.
  5. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Yes, UR-5 will work. GM HEI? Gap at .045
  6. maseusmc

    maseusmc Gunny G

    I'm sorry if either not probably explain the condition of the car. Prior to me replacing the alternator and starter she wasn't starting. I had the engine completely rebuilt and I drove the car a little while before she stopped on the road. That was in November last year. At that time I figured out my alternator and starter where worn out. This was after I tried to crank her a million times. The battery and cables were also replaced. Today I'm planing removing spark plugs and check to see if they need to be replaced. I will take all of the advice and troubleshooting techniques that you all provide. My main thing today is trying to ensure the spark plug gap space is .035 and not .032.
  7. 8ad-f85

    8ad-f85 Well-Known Member

    Maybe don't drag race with the UR5's until you make some short bursts and read them.
    The heat range is quite a bit warmer than an AC43.
    The conversion charts have plugs covering several heat ranges.
    I have good luck using those NGK's on stock or very mild builds.
    Others may have different results.
  8. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    My experience with that plug has been very positive. Of course my car is mainly street driven with one or maybe 2 trips to the track every year. I used the UR-5 in my car when it was a 13 second, 12 second, and now an 11 second car. The plug I have used since getting the aluminum heads on is the FR-5. It is the exact same plug except it is a flat seat gasket type plug. They are projected nose plugs and the theory is that they have a wider heat range because they place the gap further into the chamber. I believe I read somewhere that they run warmer at low speed and are cooled more by the incoming air/fuel charge at higher RPM. Not sure about that, but like I said, I believe I read that somewhere. The stock plugs for the 70's V-8's was an R45, and that crosses over to the UR-4. I believe the UR-5 is closer to a R43, and there is a UR-6 which is cooler still. NGK numbers go up the cooler the plug. In any case, these plugs look perfect to me when I take them out, golden brown to light gray. Might not be the best plug for a Race car but they do well in my street car.
  9. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    If I was you, I would jump all over this on E Bay,

    According to what I could find here,

    The plugs are AC R44S and they are gapped at .032, but between you and me, .032 to .035 isn't going to make a bit of difference. www.rockauto listed the plug as R 43S, but I would go with the Team Buick specs unless you find out otherwise. In 1966, the gap is listed as .035 in my Guide to Buick GS book by Steven Dove.

    I think you should check the point dwell before condemning the spark plugs. A weak ignition will just foul your brand new plugs.
  10. maseusmc

    maseusmc Gunny G

    I have that book from eBay. I will go with the .035. My distributor was loose and that just got adjusted.
  11. 8ad-f85

    8ad-f85 Well-Known Member

    Good info Larry.
    The color is an indication of mixture, if it really can be seen reliably with the variety of pump gas blends.
    It's nice when you can.
    Heat range can be seen by the first few threads of the plug body being burned to clean metal, that's just one way.
    Heat and timing marks can be seen on the ground strap, along with heat indications on the porcelain.
    For more reading Google "4 seconds flat, spark plug tech".

    One thing I like to do is try different ones on the same bank, 3 at a time with the rest being your favorite plug.
    The engine will let you know what it wants.
    This works well with odd combos or things like motor homes with ign. recurve work and headers.
    The book is often way off on those.
  12. maseusmc

    maseusmc Gunny G

    I think the engine was flooded before and I never tried to fix it. Could that be a major - minor issue? I'm look at the NGK 7189 and the ac delco rapid fire
  13. P-R-N-D-3-2-1

    P-R-N-D-3-2-1 Well-Known Member

    sometimes plugs can become gas fouled and then refuse to spark but often work fine once dry.

    had a old dirt bike once that had 2 spark plugs in the head just for that, you only used one at a time n moved the plug cap when one went funky so you weren't stranded.
  14. Nothingface5384

    Nothingface5384 Detail To Oil - Car Care

    Ive never paid any mind about to the spark plugs
    ive purchased
    but id imagine everyone gets resistor spark plugs versus non resistor due to radio/cd player and other electronics?

    Thing is it doesnt seem like you cant find a straight up coopper spark plug in resistor..theyre usually nickel tipped which is worst conductor
  15. maseusmc

    maseusmc Gunny G

    So I bought the AC Delco spark plugs. They're .035 gapped and I checked the gap with the gap tool. Even bought a torque wrench . So this is the weekend I will finally have time to take 30 mins out my day and put the new plugs in. Before I replace the plugs, should I use anti-seize or not? I want to lightly lubricant the treads with some. What are your thoughts on it?
  16. maseusmc

    maseusmc Gunny G

    I bought the ac delco r43s off rockauto for less than $2.00 each. Shipping took extremely long. I should've just went to auto zone around the block from my house....
  17. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    IMO, you do not need anti seize for plugs in iron heads. Anti seize can interfere with heat conduction from the plug to the head. The plugs for iron heads are tapered seat. Tighten them by hand, then just another 1/16 of a turn, that's it. Don't over tighten them.
  18. maseusmc

    maseusmc Gunny G

    So here are a few photos of my spark plugs I'm also adding the rusty thermostat. I replaced the old parts with new ones.. Still no start. The car is cranking just not turning over. I have sprayed starter fluid in the carburetor, no start. I did hear a few snaps & pops but it didn't turn over. I tried a couple times and it didn't work. The car was running before. So, tonight I took all the spark plugs out and I'm letting it sit overnight and tomorrow I'm putting the new spark plugs back in along with the new wires, and OE fuel pump and filter ($70.00 NAPA). The battery was purchased roughly 2 years and I haven't had it check. Maybe that's the first thing I should have checked but doubt it's the problem. Could someone look at these plugs and let me know what type of problems the engine has? Please note, this was a rebuild that I had the service completed at Woodall Service Center in Leander, TX.

    Attached Files:

  19. puddle

    puddle Silver Level contributor

    I'm thinking it is not the spark plugs that are bad, from reading this thread. First, you need to determine that you are getting spark or not. Pull a plug wire and using a plug out of the engine, ground the plug. Have a helper crank the engine and watch the plug for spark. If you have spark, I would say you have a timing issue since you mentioned the distributor was loose. If that is the case, use a timing light while cranking to get the distributor back in a range where it will start. Then set the timing to spec once it is running. If you have no spark, check the points for gap. Turn the distributor so the rubbing block on the points is on the high part of a cam lobe so the points open as far as they will open. Measure the gap--it should be .018" for new points and .016" if used. If that does not do it, check the condenser and coil.
  20. Mopar

    Mopar Well-Known Member

    The only thing I have ever saw make a car backfire through the carb is bad timing, or plugs wires put on wrong. Also be careful when you
    have a backfire cause there is a small roll pin in the gear of the distributor that will break when stressed too much and it will mess up your timing very badly.

Share This Page