71DropTop

I have been told that I need a hotter spark plug . I have been using the r34ts or r44ts ac delco but I don't know what I have in right now .The heads have been shaved a little if that makes a difference. Any suggestions??? :cheers:

lbell101

43s are stock for your engine. Maybe I'm thinking backwards here but I would think shaving the heads or building up the engine would require a colder plug.
What kind of problem are you having? Are your plugs fouling? What color are the insulators on the plugs?
Alot of times people try to cover a different problem by running hotter plugs.
Man that car looks good!

71DropTop

Larry, The mechanic did a little carb work yesterday and suggested a hotter spark. as for problems where do you want me to start :sad: :sad:
mainly carb, vac and timing but we are almost there..
BTW between me and you :lol: how would you feel if you thought the BB was running great and not knowing that the secondaries were not even opening because they were stuck :D thats what I get for never owning a vette before :D

cardo0

Hello Drop Top,
Plug heat depends mainly on your compression and cam. The old method that I recall was to run colder plugs (any manufacture) one attemp at a time on the street untlil your producing some black smoke on acceleration or at least some black soot on the plugs.
For performance at the strip/track (wide open throttlle), the coldest plug possible is desired but may not work well enough for street use.
My recommendation would be to dial in the carb first - get a O2 monitor installed. Then set up your timing for your use. Fine tune your fun machine with plugs almost last.
Big blocks make big power and I'm shure your have lots of on your discovery channel.
Best of Luck :chevy

SanDiegoPaul

On cars w/headers, we use Accel Shorty plugs. Available in most heat ranges for SBC and BBC motors. :chevy Keeps the wire boots off the headers far enough to where they won't burn.

Good luck.

MotorHead

I have read a couple of your posts and I would get a second opinion if I were you.
1) Your mechanic recommended hotter plugs, usually when increasing the compression ratio etc. you go to a colder plug.
2) Your mechanic was suggesting that your cam was pulling in so much gas that the spark plug would not ignite it. Get a second opinion on that too, however a MSD igintion will not hurt.

Just my 2c and just trying to help out :D

norvalwilhelm

Foir a bigblock I like accel #276 normal heat range and #274 one step colder. I run staggered plugs. The front passengers side tends to run lean so it gets a colder plug. They also come in S276 which is shorter for tight locations.
If your running into plug fouling problems then the carb is not set lean enough. Running hotter plugs is just to keep them from fouling and not solving your richness problem. You will wash the cylinder walls down with raw fuel, get terrible gas mileage and make less power then a leaned out motor. You can run your plugs just about white or 15-1 for normal cruising with a proper set up powervalve the mixture will richen up to a safe 13-1 when you call for power.
Go with normal Accel #276 plugs and get the carb fixed. :)

71DropTop

As much as I hate to admit it I think the cam is too much for my application .
trying to look stock but perform. so I have decided to take the cam out and replace it with a close to stock cam. This should eliminate all the problems from the past 6 mos... :mad :mad

cardo0

Drop Top you need to drop more information about your troubles. What is wrong? Rough Idle? Backfire? Surge? Stumble? Carb type? Cam size/duration? Compression?
Did you know that a larger cam reduces the bad effects of high compression? The more overlap the less chance of detonation. The large overlap hurts your carb idle circuit as the idle ports somtimes won't flow enough air. The Holley scientists will sometimes drill holes in the primary butterflies to let the carb breath at idle. Other carbs may use a different trick. You really need a good dyno or at least carb specialty shop to do what they can.
I got the impression you might be spending gobs of $$ and/or effort and be going the wrong way with a cam change. You may be in over your head and should seek out the pros in your area unless you enjoy pain. :confused:

71DropTop

I have been talked into an msd#8572 as long as I can still use the stock Dist cover and the ms6 box.. I will try this before anything :smash: :smash:
one step at a time