Spark plugs for 350 what are you using and why?

Discussion in 'Small Block Tech' started by scott kerns, Apr 11, 2010.

  1. scott kerns

    scott kerns Silver Level contributor

    Wondering....:idea2:
     
  2. V8Sky

    V8Sky "Scarlett"

    AC Delco.
     
  3. Phil

    Phil It really *is* a 350...

    I use AC plugs but I know they're "colder" than stock. Good thing is I have no engine knock, bad thing is that until the car warms up it runs a little rough.
     
  4. GotTattooz

    GotTattooz Well-Known Member

    I run Bosch Platinums. It's the only plug I've never had a problem with.

    -Josh
     
  5. smokum

    smokum Well-Known Member

    I've used E3 plugs on 4 Buick 350-equipped cars I've had, and I've noticed they never foul and always look really clean.
    They advertise that their plugs have better fuel burn and produce more power and gas mileage. They don't have to be gapped like traditional plugs because the electrode and strap are open in a "diamond" shape that lets the spark expand out more than a regular plug.
    They're not cheap (usually $5.99 ea. through Summit or Kragen/O'reilly), but worth it. They have a 5-year gaurantee too.
    That's my take on the matter, but I was really pleased with their performance.
     
  6. ceas350

    ceas350 "THE BURNER"

    I used E3 3 newer cars that were above 1995 and had missfire and ran lean everytime. I always did wonder if the E3's would work on engines with carbs. Do you have any issuse with them like having to tune the engine to run with those plugs?
     
  7. Firehunter

    Firehunter Well-Known Member

    X2. :beer
     
  8. gstewart

    gstewart Well-Known Member

    ac delco R45TS work fine in my car, thus, no need to change.
     
  9. CraigFaller

    CraigFaller Well-Known Member

    Have AC's now, had Bosch plats in for about 10 years, no problems... just wanted to put in new ones.
     
  10. ddjayl

    ddjayl G-body Buick Freak

    I use NGK's whenever possible.
     
  11. Mart

    Mart Gold level member

    I use the R45TSX AC Delco's gapped at .060 with full MSD Ign. & 8.00 MM wires. They burn very clean as they are designed for the high energy ignition systems. (Hence the .060 gap). Plus I got 11 sets from a friend for $10.00 :TU:
     
    Mark Demko and MrSony like this.
  12. Justa350

    Justa350 I'm BACK!

    NGK V-power (or something like that). I use them because they have multiple sharp edges around the electrode tip and resist fouling better than regular tip plugs. They are also really nice with the turbos, solid firing, no glow plug effect that platinums have.

    That said, if I were still running N/A I would be using the Bosch Platinum-4's. That's what I had pre-turbo. Killer plugs. Really hot at the tip so they never foul or load up, even with the rich idle our 350's like. I was able to run loads of initial timing and a really aggresive off-idle tuneup with the Platinum-4's and the car loved it. It would break the big Mickey's loose with just a tap of the gas.
     
  13. TXGS

    TXGS Paint by numbers 70 GS 455 4spd

    I run NGK UR4 Vpower in my 449hp 350. Runs Great
     
  14. drflow

    drflow New Member

    When I removed the heads from my 1979 350, I noticed that AC Delco plugs (with the slightly extended shell) fit flush with the combustion chamber.
    I had planned to change over to Bosch plugs and noticed that some threads in the head were left exposed because they did not have the extended shell.
    Not wanting to grind out the exposed threads, I used the OEM replacement AC plugs.

    Paul S
     
  15. gymracer01

    gymracer01 Well-Known Member

    Plugs should come to end of threads and not extend into chamber. Problems arise when someone has been using a short plug and you try to put the correct in and the threads are carboned up. Then the holes need to be "chased" with a 14mm tap.
    Jim N.
     
  16. RipRohring

    RipRohring 53 SUPER V8 12 Volt

    :Do No: Following the thread, but can I add a Question ?
    .
    On my 322 Nailhead; vintage 1953 - my mechanic pulled and threw out my A/C Delco plugs and replaced them with some NGK's. :dollar: :af:
    .
    $80 w/labor.
    .
    Swears by 'em - they run hotter - he told me. :bglasses:
    .
    He puts 'em in his Concourse 1948 Caddy Convertible.
    .
    I wasn't having any backfires BEFORE he pulled the plugs, and the car is running good now. I don't know the part # for either set. :rant:
    .
    Any ideas or comments ? :3gears:
    .
    RipRohring :Comp:
     
  17. mjt

    mjt Well-Known Member

    $80 to change out plugs? Wow.

    I'm running NGK BP5HS in my 64 - I pulled them after about 700 miles
    and the coloring looks great. The manual calls for a ACDelco 44[ff]s,
    which, of course, is not made any more. The recommended replacement
    is the R43fs, which is a colder plug. Rumor has it NGK manufacturers
    plugs for ACDelco.
     
  18. EasyCompany7

    EasyCompany7 Semper Fi

    I tried the Bosch platinums in this 350, but within a week they fouled out due to the richer than stock jetting in my Qjet. I went back to the stock ACR45TS and they burned cleaner and consistently from #1 to #8. I've experimented with different gaps........

    less than .030 has a rougher idle and the plugs accumulate fouling over a week, no miss at 5300 rpm.

    .030 to .035 has better idle, takes a little longer to foul, no miss at 5300 rpm.

    .035 to .040 has good idle, no fouling, no miss at 5300 rpm.

    .040 to .045 has good idle, no fouling, some miss at 5300 rpm.

    .045 to .050 some idle stumble, some fouling, noticeable miss at 5300 rpm.

    At this point I installed an MSD 6AL because I wanted the multiple spark at lower rpm and consistant spark at spark at 5300 rpm. After the MSD install, the idle was smoother, another .5 inch of vaccum, and consistant pull all the way up to 5300 rom, (whereas with the stock i could feel the flatness above 4800). I experimented with the gaps again, but didn't bother with the small gaps because i was looking for the largest gap for the most burn without the high rpm miss. Found that i can now run between a .045 and .050 with the best idle and no high rpm miss.

    I have Accel U-grooove 276's in there now at .045, this summer i'll experiment with the gaps on those no doubt.

    BTW, it's the stock '72 distributor, points converted to petronix, installed limit bushing, lighter springs and weights. no vacuum advance, 12 degrees initial, 33 degrees all in at 2400 rpm.
     
    Quick Buick likes this.
  19. scott kerns

    scott kerns Silver Level contributor

    Wow Easycompany! I admire your experimentation and the posting of the results. I was hoping for information just like this. :TU:

    Thanks


    Anyone else?
     
  20. Steve Craig

    Steve Craig Gold Level Contributor

    X2.
    Also note the "R" indicates use for radio interference suppression.
     

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