faulball67

iTrader: (2)

I've got a 350 I just rebuilt in my camaro. I'm currently running AC Delco R45TS plugs at .045 gap. I keep having to pull the plugs and clean them. They come out loaded with soot. I'm wondering if I should go up to a R46TS for a hotter plug or if I should switch from the AC Delco's to another kind of spark plug (splitfire, champion, etc.). My only problem with switching plugs is figuring out the heat range to use for the brand.

Sonix

iTrader: (1)

the obvious question that comes to mind is, are you running rich?

faulball67

iTrader: (2)

I've got it a hair above as lean as I can get before it starts to bog down and miss. I've got a rather large cam and 1.6 roller rockers, and running 10.5:1 pistons. It just seems to leave excess carbon. That's why I was thinking about going with a hotter plug. It would burn off more of the cabon from the plug. I just worry about detination with the hotter plug. I don't run anything less than 93 octane I was also considering a new plug I just found in Super Chevy. They're ZEX Igniter core. They're supposed to have a better spark and self clean the electrode and surrounding area.

F-BIRD'88

The plug heat range is fine. Infact for performance use its a little too hot.
the plugs are loading up because.
1. you have a manifold vacuum leak and are having to adjust in extra fuel to compensate.
2. the power valve is blown or the power piston ( metering rods) is stuck "up" in its bore.

or the carb gaskets need replacing ( holley metering block)

3. need more initial ignition timing at idle.
This will allow you to return the carbs throttles to the optimum position at idle. (.020-.030" transitin slot exposure)

4. did not hook up a PCV valve or are not venting the valve covers on a carb with a PCV vacuum fitting on its base( most street carbs) causing the idle circuit to be rich(er)

5 ignition problem causing missfireing or a weak spark.
Coil cap rotor wires. ignition box, grounds. ( mismatched coil and HEi module ( very common ACcEL problem)

A combination of all the above.

When you get it all sorted out you'll find that a cooler performance oriented plug like a R42T Or TS will add some detonation protection yet stay clean at idle and not load up.

What cam,,, what carb,,, what jetting what intake manifold???? are you using.

faulball67

iTrader: (2)

I running a comp cams magnum hyrdaulic flat tappet cam with 244int./244exh. at .050 inch lift. The carb is a holley 4 barrel 750, 4160 series carb with 69 jets and vacuum secondaries. The intake manifold is an older edelbrock scorpion which is going to be replaced with a new performer manifold in the near future.

I'm thinking I need more timing add too get a whole new distributor setup.

Sonix

iTrader: (1)

not quite sure what you meant by your last line....

nonetheless, thats a lot of cam, and would like a lot of initial timing, like 16* or more, and i'm guessing it's not quite high enough....

TABBOO

I would appreciate if F-Bird 88 could elaborate on the Accel coil & ignition module mismatch problem. I have an Accel ignition module & an Accel (superstock) coil. I think it is called a superstock coil. It is the yellow one that is made as a direct replacement for the stock coil in an external coil TA.
My car is an 87 TA with a 305 TPI.
I just had a mechanic tell me my Splitfire triple platinum plugs were fouled & he said I was better off with AC Delco r43ts plugs. Something about V-8 motors not running hot enough for platinum plugs. Could it be my coil & ignition module combo or was he just lying about the platinum plugs not working in my car.

Sonix

iTrader: (1)

platinum plugs suck. They last longer, but they aren't as good. Get good at changing your plugs, and use good 'ol copper plugs.

faulball67

iTrader: (2)

Just meant I think I needed to advance the timing some more and go with a better ignition setup instead of the stock style hei with built in coil. I 'm wanting to switch over to a MSD setup with an external coil/box setup for getting more accurate and more powerful spark. It just costs so damn much and I've already spent more than I had planned.

F-BIRD'88

Your problem is the idle /low speed carb circuit and idle throttle position ,,not the jetting.
Go buy a set of new Champion RV8C or GM DELCO R42T plugs and gap them at .035" accuratly. Put them in. your old plugs are now trash.
A expensive plug , hot plug or trick plug is not required.
A MSD6al will not correct this problem.

Correcting the timing at idle and resetting the carb correctly,, will...

You need much much more ignition timing at idle for that cam.

I would: Lock out the mechanical advance for full advance all the time. (34-36deg).
you can do this by removing the rotor, remove the advance weights and springs and using plastic tie wraps fix the mechanical advance mech fully advanced so it cannot move. Orient the tabs of the tie wraps down to clear the rotor. re time the ignition timing using a light ( 36deg)
Then remove the carb flip it over and look at the throttle blades.Reset the throttle blades in reference to the fuel transferslots (.020-.030" exposure on both primary and secondary. reinstall it.

Hook up a PCV to the carb just like a stock vehicle and vent the other valve cover.

Install a 3.5" power valve. change the carb jetting to 72 pri and 83 secondary. The old scorpion intake is air gap design and will take longer to warm up than a stock intake will.

you'll find that the car now idles much better.

Now running the distributor timing locked out tends to put a lot of strain on the starter when hot. So now recurve the distributor to achieve 24deg initial and 36deg at high rpm. (10-12deg of mechanical travel) You have to physically shorten the mechinical advance travel limit within the distributor to get this. then use mediun weight advance springs. ( lightest ones are unnessary and unstable at idle)
you will want to tame down the vacuum advance travel also. The typical 20deg at high vacuum will be too much. Limit the travel to 10-15deg at high vacuum. by limiting the vacuum advance rod travel.

Let the car fully warm up.

readjust the idle mixture screws to get best idle quality and adjust the idle speed screw just enough to get a steady idle at 800rpm

Accel coils come in different types that match diferent specific HEI modules ( coil wire color) They can cause a stock GM HEI module to not function properly.
if you don't have the right one.

I prefer MSD HEI coils and modules. Much better and do not interfer with the Stock GM module if you choice to use it. the MSD HEI stuff is just better stuff.
I use a stock GM distributor with modified advance, a stock GM module and a MSD HEI coil. MSD heli coil wires.
My car is just a radical as yours is and my plugs last years.
This is all the ignition power you need.
I've never had much luck with ACCEL products except the high perf ignition points back in the day. the rest of the product line ....seems to leave a lot to be desired.
if it works for ya fine.
Be sure to electricly ground the engine to the firewall. makes a difference.

Once you correct the timing and carb setup your new plugs will stay clean. A hot plug or super duper ignition box is not going to fix it.

Sonix

iTrader: (1)

?
I just have one little q f-bird, if I may:
why tell him to lock out his dist for full mechanical advance to 36*(that means 36* timing all the time right? with no change?), then re-curve it? why lock it out in the first place?

you could also use manifold vacuum on the vacuum advance, then not have as much initial advance, and not have to mess with the mechanical advance, correct?

F-BIRD'88

Locking out the distributor (temperairly) with full 36deg at idle will allow him to get the carb setup correctly and get the engine running right.
then he can tear down t the distributor and modify it.
for best timing curve for his cam.

you need high physical initial timing at idle with a big cam like the 292H magnum. the engine wants a full 36deg at idle but 24or so at idle will get you by and not strain the starter motor.
(camOverlap's EGR effect ( rough idle) at idle slows the fuel burn rate requireing more timing lead at idle)

Trying to get more timing at idle with vacuum advance at idle will not work and is unstable because timing will drop as the manifold vacuum drops resulting in a serging /hunting unstable idle.

More initial timing and ported vacuum advance ( no vacuum advance at idle) is much more stable.

the car will run clean with 24 initial 36 total all in by 3000-3500rpm and additional 10-15deg vacuum advacne at high cruise.

A "crank start retard" box would be ideal allowing full timing at idle and easy starter cranking.

Sonix

iTrader: (1)

huh, you should tune your carb with your engine idling at full advance eh? Never heard that before... Or I guess with the amount of advance it *should* have at idle...

oh yea, that won't have a lot of vacuum anyway...

faulball67

iTrader: (2)

I'll give it a shot and see what happens.
Thanks

Wayne's 383Iroc

sent you an E- mail faulball67, may help

1983Fbody

Just thought I would throw in some advice here for anyone locking out their mechanical advance. Dont' use 1/8" poprivets to lock out your mechanical timing, I can't imagine small zipties would be strong enough either. They will break in a matter of time. 1/4" pop rivets are holding mine together as of yet, tack welding is probably the best solution or the larger zipties will work for awhile. If you end up using rivets be careful not to get metal bits down into the timing pickup when drilling.

F-BIRD'88

Zip ties (electrical tie wraps) will hold fine. Mine have been doing the job for years. Allows you to go back and reinstall the weights and springs too if your combo changes.

Sonix

iTrader: (1)

aren't you only locking it out with the zip ties temporarily? like 1/2hr max?

F-BIRD'88

Mine is "locked out" all the time. The zip ties are working fine. I guess you could find some cheap stuff that will fall apart, but.....My cam is big enough to need this much advance at idle. I have a programable ignition retard box (nitrous) that also knocks back the timing up to 20 deg while starting the motor. to ease the load on the starter. It restores the set timing as soon as the engine starts. Most must be used with a CD ignition like MSD, mallory or ....

factory Ford "Duraspark ignitions" had this feature built in as well. one of Ford's few "better ideas"

Either way works. Locked out with carnk retard or employing as much initial at idle as your starter will withstand. and then curving n the mechanical to get 34-36 total. I found 22-24 initial about right overall for cams over 230@.050 with a rough idle.

Exhaust header heat is real tough on GM starters but incorrect timing just make the motor, cylinder walls, cylinder heads and headers hotter and eventually kills the starter (usually sooner than later) Slow burn with retarded timing heats up the surfaces of the inside of the motor more than pushing the piston. ( making power)
A starter heat shield really helps.

GM should have designed this start retard into the HEI ignition module.

faulball67

iTrader: (2)

My dad always told me to do the little things first. Just needed a brand new set of plugs. Got a set of R43TS and gapped all to .035 and she fired immediatley. Adjusted my timing and she runs like a dream. I guess I flooded the old plugs a couple too many times and they just weren't sparking right.

michal_larson

hehe, initial timing rulez
----------
my inital is at 32 degrees, and it likes it.

faulball67

iTrader: (2)

Thought I'd beat the dead horse again. I finally got my MSD 6A installed (only a year later) with their start/retard module. This has got to be the best setup I've had by far. It takes 10 degrees of timing out for starting (can go up to 25) and hooks up to my nitrous and retards the timing (currently set for 7 degrees retard) as soon as my window switch activates it. This is perfect with my mechanical advance being locked out now. Just like to thank F-bird'88, a little too late, but better late than never.