The Ford Barn

COE Dan · 11-17-2015, 11:22 AM

Fordbarners,

I'm having ignition problems on a '34 Ford pickup and discovered the truck was equipped with Champion UD16 plugs by a previous owner. These plugs have an auxiliary gap, presumably inside the porcelain insulator designed for anti-fouling purposes and cause the plugs to run hotter. However, I believe a higher coil output is needed to fire them than what the stock Ford 6V ignition is capable of producing. I believe this is why I'm having hard starting issues.

Additional data:
- Stock heads - Plugs need to have 18mm threads & 7/8ths-inch nut size
- Distributor/coil/condenser is a '37-'41 Ford 6V circuit (stock for those years, obviously not stock for a '34)

I know the '34 Fords were originally equipped with Champion 7 spark plugs. As those plugs aren't produced today to my knowledge, I need to find a workable alternative. I don't need concours plugs as I'm not trying for a EFV8 Dearborn award - I just need driveable plugs.

My questions are:
1) Champion makes a D16 plug without the auxiliary gap (colder plug) - is this the Champion I need? If not, which Champion is the correct type, if any?
2) Autolite 386 is the listed equivalent plug type for '34 Fords. Is this correct?
2) I know there are other brands but I'm not familiar with any other numbers - can anyone tell me which brands/plug numbers work on the '34 Fords?

Thanks, Dan

Seth Swoboda · 11-17-2015, 11:29 AM

Have you tried Champion H10 or Autolite 216? I have always used Autolite 216's with good luck.

COE Dan · 11-17-2015, 12:16 PM

Hey Seth, how's things in your part of IL?

I run the H10s in my '39 and '47 and I use the Autolite 216s in my '66 Falcon - they are both 14mm threads.

The '33-'34 heads use 18mm thread size spark plugs. Are the H10s/216s available in the 18 mm size?

Dan

flatheadmurre · 11-17-2015, 12:34 PM

The idee behind the UD plugs are that there is a gap in the core that forces the coil voltage to go higher then whats needed to fire a normal plug and that it should blast away the carbon on a fouling plug.
So if your coil is on the weak side it might not work well.
UD and D doesnt set the heat range so a D16 should be the same heatrange.

Seth Swoboda · 11-17-2015, 12:41 PM

Quote:

Originally Posted by COE Dan

Hey Seth, how's things in your part of IL?

I run the H10s in my '39 and '47 and I use the Autolite 216s in my '66 Falcon - they are both 14mm threads.

The '33-'34 heads use 18mm thread size spark plugs. Are the H10s/216s available in the 18 mm size?

Dan

Correct, they are bigger in size. I forgot about that.

Everything is going well. I'm getting ready to start a 59A engine build. Other than that pretty quite out my way.

I assume you finally got that '34 pickup in your hands?

COE Dan · 11-17-2015, 12:54 PM

Sponsored Links (Register now to hide all advertisements)

Seth, I PM'd you so I can keep this thread on track...

Flatheadmurre - thanks for the clarification on heat vs. anti-fouling properties.

11-17-2015, 11:22 AM	#1
COE Dan Senior Member Join Date: May 2010 Location: Now in Wichita, KS Posts: 251	Correct spark plugs to use on a '34 Pickup? Fordbarners, I'm having ignition problems on a '34 Ford pickup and discovered the truck was equipped with Champion UD16 plugs by a previous owner. These plugs have an auxiliary gap, presumably inside the porcelain insulator designed for anti-fouling purposes and cause the plugs to run hotter. However, I believe a higher coil output is needed to fire them than what the stock Ford 6V ignition is capable of producing. I believe this is why I'm having hard starting issues. Additional data: - Stock heads - Plugs need to have 18mm threads & 7/8ths-inch nut size - Distributor/coil/condenser is a '37-'41 Ford 6V circuit (stock for those years, obviously not stock for a '34) I know the '34 Fords were originally equipped with Champion 7 spark plugs. As those plugs aren't produced today to my knowledge, I need to find a workable alternative. I don't need concours plugs as I'm not trying for a EFV8 Dearborn award - I just need driveable plugs. My questions are: 1) Champion makes a D16 plug without the auxiliary gap (colder plug) - is this the Champion I need? If not, which Champion is the correct type, if any? 2) Autolite 386 is the listed equivalent plug type for '34 Fords. Is this correct? 2) I know there are other brands but I'm not familiar with any other numbers - can anyone tell me which brands/plug numbers work on the '34 Fords? Thanks, Dan

11-17-2015, 11:29 AM	#2
Seth Swoboda Senior Member Join Date: May 2010 Location: Southern Illinois Posts: 3,795	Re: Correct spark plugs to use on a '34 Pickup? Have you tried Champion H10 or Autolite 216? I have always used Autolite 216's with good luck.

11-17-2015, 12:16 PM	#3
COE Dan Senior Member Join Date: May 2010 Location: Now in Wichita, KS Posts: 251	Re: Correct spark plugs to use on a '34 Pickup? Hey Seth, how's things in your part of IL? I run the H10s in my '39 and '47 and I use the Autolite 216s in my '66 Falcon - they are both 14mm threads. The '33-'34 heads use 18mm thread size spark plugs. Are the H10s/216s available in the 18 mm size? Dan

11-17-2015, 12:34 PM	#4
flatheadmurre Senior Member Join Date: Apr 2015 Location: Sweden Posts: 3,045	Re: Correct spark plugs to use on a '34 Pickup? The idee behind the UD plugs are that there is a gap in the core that forces the coil voltage to go higher then whats needed to fire a normal plug and that it should blast away the carbon on a fouling plug. So if your coil is on the weak side it might not work well. UD and D doesnt set the heat range so a D16 should be the same heatrange.

11-17-2015, 12:54 PM	#6
COE Dan Senior Member Join Date: May 2010 Location: Now in Wichita, KS Posts: 251	Re: Correct spark plugs to use on a '34 Pickup? Sponsored Links (Register now to hide all advertisements) Seth, I PM'd you so I can keep this thread on track... Flatheadmurre - thanks for the clarification on heat vs. anti-fouling properties.