Flathead killing spark plugs?

I have an 8BA flathead in my roadster and it keeps killing spark plugs! I've tried two sets of Autolite 216's, a set of Champion RH10, and NGK BL6's. Tried gaping them at everything from .020" - .035" and nothing seems to make a difference.
I get about 4 days out of a set.
Engine is nothing crazy, stock bore and stroke, isky 400 cam, edmunds heads, weiand intake with three 97's. I've tried running all 3, and just one, makes no difference.
Stock distributor with points.
Any ideas?

 

Try an NGK spark plug. I don't have a number as I don't know the "reach" you need.

 

Could you please be a little more specific about what you mean by "killing spark plugs"? Are they fouling, the electrodes getting burned, or what?

 

If you read the post he said he tried NGK B6L's.

I had a similar problem last year, very similar flathead setup to yours, two carbs. not as bad, would start misfiring and popping after a 1000 miles or so, replaced plugs and it dissapeared.did this three times, gave it a big tune up went down two jets in the 94s and changed a few other things and it went away..never really got to the bottom of it..I guess it was a bit rich..If you are running three carbs that may be the trouble. good luck!
Oh and Im running NGK B6L's now, they are all that is easily available here. Champion H10s are dear and hard to find in a hurry.

 

By killing spark plugs I mean they quit firing. It will start popping out the exhaust and missing then just quit firing all together. Change the plug and it runs great again...for four days or less. Last month I changed the plugs 3 times, drove the car maybe 200 miles.

 

What color are the electrodes when when they fail, black, brown, white?

 

Try using AC's.

For some reason, NGK's fail like that. I had the same problem more than once.

Somethimes over-torquing can break them internally

 

I doubt if it's plugs. You ask 10 guys and you get 10 different plugs to use. I always run the good old Champion lawn mower plugs. I've got a similar engine with about three years on them.
Why are you running the stock distributor with dual or trip carbs? That Loadamatic is the sorriest piece of shit that Ford ever made....
The condenser might be going away when it gets hot. I'd look toward the ignition.

 

Charging system and ground wires >>>>.

 

When they fail they are black and soaked in fuel. The rest of the plugs are a little rich, but not wet.
As for the distributor, the reason I'm running a stock is my Mallory Mag Spark was too finiky. One day it would work, the next day it wouldn't.

I too think it's something ignition related and not plugs. Could it be the cap and rotor maybe? Hairline crack?

 

Also another thing I should mention. Plug number 1 and number 8 are always the first two to go. I've changed those two plug wires with new ones, and they still failed.

 

My 33 pickup did that. I had two 97's on it, it was too rich (221 C.I.). It would foul plugs all the time. Threw a couple 81's on it and have had the same plugs in it ever since

 

I'm running2 94's on a 239flattie.I'm using#48mainjets and 7.5powervalvues.I alsorun champion H12's for plugs.If you got a stock distributor,make sure the vacuum is hooked up to ported vacuum.
Butch

 

It's not the plugs. You're running too rich and your don't the correct advance curve with stock distributor.

 

I'm also guessing you have stock main jets, 45s. as well, which could be a big part of your problem.

 

How can you be running 97's with a stock 8BA distributer. You are not getting the correct advance at all. Read about these distributers. You need to change that thing right now.
94's with the venturi vacuum are required with a stock 8BA dizzy.

 

Exactly. The dead plugs are the result of a problem, not the problem itself.

Bob

 

The plugs are failing because the engine is running too rich. There could be a couple of reasons why. Timing, jets. Where are you getting the vacuum for the distributor? Are you using progressive linkage for the carbs? I also suggest reading the thread about the distributor vacuum above. If you have the vacuum correct, THEN look to the carb main and idle jets, contact Uncle Max Musgrove, he can suggest the proper sizes.

 

Hear, hear!

 

The vacuum advance is currently hooked up to a port in the intake manifold. I've been researching this all morning and now know this will not work.
I guess my next question is, what needs to be done to the stock dizzy to make this work?
I've searched here on the Hamb but haven't been able to find much.

Thanks for all the responses so far! Much appreciated!

 

just get ahold of GMCBubba and get one of his sbc conversion dizzys. Make everything better. Its like viagra, rogaine and HGH for a flatty. (without the negative side effects of course.)

 

Stock distributor fix, throw it in the trash can! buy a converted GM distributor from GMC Bubba. Also look at running smaller jets.

 

you need to replace it! have gmc bubba build you one!

 

I agree with the comments on the stock distributor. One other thing that you can easily check is to make sure that the little plunger in the power by-pass valve is working freely. Mine were stuck in the open position allowing excess fuel to flow into the cyclinders. I've ran NGK B6L's for years without any problems.

 

You are definitely running retarded at full throttle with your hookup, likely running not too far from decent advance at cruise/part throttle with vac to manifold. Retarded somewhat mimics results of rich, but in any case you CANNOT flog carb tuning when advance system is known to be FUBAR. Kill off the known problem FIRST, then figgerout carbs.
Converted Chevy distrib is a good path. I would skip current Mallory as it needs complete restoration and recurving new out of the box! Don't know anything about MSD flathead distributor but suspect it is likely good. Do not buy Chinese knockoffs of MSD...
A reason to go th the Bubba distrib is to get one that has a known decent curve and can just be run...simultaneously getting a distributor with unknowns and triple carbs would be a serious tuning headache as you chase problems in the wrong system!
PS...while the wrenches are out, I would throw on the stock manifold temporarily and run in the ignition and then each carb separately with single carb. Then you are ready to tackle the triple!

 

I would try an MSD box first. Makes the points last longer too

 

That won't help...the '49-53 distributor does fine lighting the sparks, and points'll go fine for 10,000...its problem is a worthless advance, especially at open throttle, that gets worse with almost any engine mod.

 

got ya

 

You mean, no erections lasting longer than 4 hours?

 

Ok so with the bubba dizzy, does he build them all the same, or custom for each application?
Reason I ask, my shoebox ford has a bubba dizzy in it, that I was thinking of swapping in to try.

Another thing, what did they do back in the day to fix this problem?