Spark plug question

[wahya]

A few months ago, I started noticing that my car was getting harder to start. Travels and other things got in the way and the car sat for about 3months. The other day I attempted to get it started and it cranked good, but not even a cough or sputter. I tried again the next day and the same thing. I was getting gas to the carb so I figured maybe no spark.
I pulled the plug wire to #1 and held it with pliers next to ground while my wife cranked. To my surprise, the motor started right up. I put the wire back on the plug while running and no difference in the idle. So I shut the motor off and took the plug out. It was black and sooty looking and also had a bit of oil on it.
I called a friend about my concern and he asked if I had a leaky valve cover. Sure enough, it was leaking oil that had pooled a bit around the plug. Ok, so I guess that in the process of taking the plug out, oil ran down the threads,
I bought a new set of plugs and first replaced just that one bad one. I pulled the wire while motor running and it now made a difference, put it back and it made a difference. I went ahead and replaced all plugs, btw , all the old ones look the same, all black and sooty looking. I know that I’m running rich (at least I think so), but I was wondering why removing the one wire aloud the motor to start. Could internal of the plug ground out the ignition, or somehow having the oil leak there cause this issue.

 

[Geoff 2]

I think it was just coincidence. What engine? Stock or close to stock should use NGK 5 heat range.

 

[493 Mike]

A few months ago, I started noticing that my car was getting harder to start. Travels and other things got in the way and the car sat for about 3months. The other day I attempted to get it started and it cranked good, but not even a cough or sputter. I tried again the next day and the same thing. I was getting gas to the carb so I figured maybe no spark.
I pulled the plug wire to #1 and held it with pliers next to ground while my wife cranked. To my surprise, the motor started right up. I put the wire back on the plug while running and no difference in the idle. So I shut the motor off and took the plug out. It was black and sooty looking and also had a bit of oil on it.
I called a friend about my concern and he asked if I had a leaky valve cover. Sure enough, it was leaking oil that had pooled a bit around the plug. Ok, so I guess that in the process of taking the plug out, oil ran down the threads,
I bought a new set of plugs and first replaced just that one bad one. I pulled the wire while motor running and it now made a difference, put it back and it made a difference. I went ahead and replaced all plugs, btw , all the old ones look the same, all black and sooty looking. I know that I’m running rich (at least I think so), but I was wondering why removing the one wire aloud the motor to start. Could internal of the plug ground out the ignition, or somehow having the oil leak there cause this issue.

By increasing the gap the coil produced a little more voltage to jump that gap, hence the start. My guess.
Mike

 

[wahya]

A bit aggressive cam solid lifters. Old plugs still at .35. (360) Not sure of heat range on this, I know, Champion plug.

Increasing the gap? All I did was hold the wire close to ground (block), I thought I might be able to detect a spark. Should the gap on plug be increased.

The car doesn’t get to be driven the way it should. I’m thinking that might help on the plugs, but always thinking one of these idiots around here is going to run a stop sign and pull out in front of me.
When I was adjusting the TQ carb a long time ago the motor seemed to run best a little rich. I’ve leaned it out a little. May go more. This is that #1 plug.

 

[493 Mike]

A bit aggressive cam solid lifters. Old plugs still at .35. (360) Not sure of heat range on this, I know, Champion plug.

Increasing the gap? All I did was hold the wire close to ground (block), I thought I might be able to detect a spark. Should the gap on plug be increased.
No. .035" should be good. What type of ignition system do you have?
The car doesn’t get to be driven the way it should. I’m thinking that might help on the plugs, but always thinking one of these idiots around here is going to run a stop sign and pull out in front of me.
When I was adjusting the TQ carb a long time ago the motor seemed to run best a little rich. I’ve leaned it out a little. May go more. This is that #1 plug.

View attachment 1739927

Mike

 

[wahya]

Sorry Mike, I didn’t see you question imbedded in there. Old school points and condenser. Ron.

 

[Geoff 2]

I can see a Champion '14' in the pic, which is equivalent to an NGK 5. That should be hot enough in terms of heat range.

Plug looks very rich. Is the car smelly at idle? Rough idle? TQs are a great carb. The best 4bbl.
With the engine idling, using a torch, look down the pri throttle bores & see if you can fuel dripping. Report back.

I would also think about losing the points & switching to a GM HEI 4 pin module. You could keep the points & they can trigger the module. HEI allows bigger plug gaps, more reliable ign. Used with an E core coil, you get over 80% more energy than points/condenser ign.

 

[wahya]

Yes very rich, that’s the one that failed, but they all look the same. The car is smelly at idle, but once it warms up a bit it runs fairly smooth. It’s when I try to lean it some, that’s when it runs rough. I noticed that when I turned one screw to the right maybe a little less than a quarter of a turn, the motor starts to run rough I backed off on that and it got smoother. The same with the other side. At that setting, the motor doesn’t run as smooth, but it is less smelly.
A torch, as in flame, or is that a down south term?
I may look into that HEI. When I first bought the motor, my builder told me what to get (I don’t remember now), but the dang thing would run about 15 minutes and die. I went up to the auto parts store and bought the original equipment and it’s been there ever since, I believe that was about 12 years ago.

 

[493 Mike]

"torch"=flashlight
Mike

 

[wahya]

"torch"=flashlight
Mike

Glad I asked.

 

[RJRENTON]

"torch"=flashlight
Mike

The term "torch" came from U.K. (British or European origin) ....and does connote flash light......
BOB RENTON

 

[493 Mike]

The term "torch" came from U.K. (British or European origin) ....and does connote flash light......
BOB RENTON

It does in the answer Geoff 2 responded with.

 

[RJRENTON]

By increasing the gap the coil produced a little more voltage to jump that gap, hence the start. My guess.
Mike

The coil produces the same secondary voltage every time, as determined by the coil's volts/turn ratio. The plug gap determines when/if the available voltage can jump the gap or if any crud on the center electrode/insulator inhibits the spark from jumping the gap. The plug's electrode configuration (V gap, J gap, cut back gap, side gap, etc.) helps to determine the ease in which the spark can occur. Consult the Champion or NGK design examples, by application.
BOB RENTON

 

[lewtot184]

If it were me I'd chase the fuel problem first and do spark plug stuff second.

 

[wahya]

If it were me I'd chase the fuel problem first and do spark plug stuff second.

I was thinking the same thing.
geoff2, hopefully get that other info today. Got wore out yesterday taking hurricane shutters down, cleaning up the yard and pumping water ( drainage sucks around here).

 

[RJRENTON]

If it were me I'd chase the fuel problem first and do spark plug stuff second.

Simply re-jet the carb several steps leaner, via metering rods and/or metering jets, to see if there is an improvement in plug coloration. The Champion -14 plugs are "hot"; after correcting the carb, consider a Champion N-12Y or current venue RC12-YC ot the NGK equivalent. If the application can tolerate more ignition advance, 36° Total @ 2600 - 2800 RPM without vacuum advance (neither ported or manifold sourced). Just an additional consideration.....
BOB RENTON

 

[wahya]

Without getting in over my head on some of this, I have leaned it with the adjustment screws. The exhaust is more tolerable now as far as smell. I’ll probably leave it like that and check the plugs again after driving a bit.
Geoff2, I have checked the carb at idle and can’t see any gas dripping (with light).

From what I can tell, this is carb for 1980 360 truck if I have read it right.

I got to thinking. Many years ago, I was talking to a neighbor about the unused “nipples” at the rear of the carb. He was saying that the large one, second from right side, went to bowl. He said “back in the day, it was common to run hose away from engine that way”. I don’t know if that was true, but I ran the hose outside. I noticed that there was a slight suction on that hose and I put an inline filter on the hose, not wanting to suck in any crud. Should this hose be left open, or what. I read somewhere about a solenoid going there.

 

[Geoff 2]

I can see at the back of the TQ the emission hose on the driver's side.
What are the cam specs? My guess is that the t/blades need to be open more at idle [ normal with more cam duration/overlap ] & this is causing a rich idle...& sooty plugs. If the idle mixture screws do not have much affect on idle, & will NOT stall the engine when fully seated..........then that is a good indication of the above scenario.
Is the air valve dashpot on the carb? It mounts under the passenger side rear mounting bolt/stud & it's rubber hose plugs into the nipple on carb base, nearest the mounting bolt.
I do not know much about the emissions stuff on these later models.

 

[wahya]

That hose on the driver side is blocked off. Sorry, I don’t know the cam specs. I do know that the mixture screws have affect and will stall motor if I go to far in. Yes on the dash pot, (edit)
When I was looking for an engine a long while ago, I saw a 340 that was for sale on eBay. It turned out that the guy that was selling it lived about 10 minutes away. I went to his place and we were discussing what everything was going to cost and he said, hey I’ve got this 360 here. As far as your bang for the buck, it might be the way to go. I told him I wanted a slightly aggressive cam. He built the motor, threw in the TQ, headers, a few other things that I needed and helped me with the install. I should have asked more about details of the stuff you’re asking. I had to go and look up what a dash pot was.
All I know is this motor will run. I only got on it good a couple of times and I squished one of the motor mounts. (Cheap, but lifetime warranty)