Over the weekend I got my '49 F-2 out of winter storage. Last year before storing it for the winter it wouldn't start, it was too dang cold that day to mess with it so I pulled it down to the storage shed and parked it. This weekend I started working on it to see what the problem was, feeling it was an ignition problem. The truck has a stock 226 flat six engine. Started checking for spark, first place spark plugs. When I pulled plugs I noticd the gap looked too small. Checked the shop manual and sure enough, the gap was about half the size. Any idea why the gap would close up? I'm 100% positive the gap was correct when I cleaned and reinstalled them last summer. Ran fine last summer after I tuned the engine up. I am sure I have the correct plugs.

BTW, the reason the truck stopped running was because I crossed #2 and #4 wires. I had to stop driving the truck toward the end of last summer because I broke the driver's side front spring and didn't have a replacement at the time. In the mean time I bought a parts truck with a 226 that was messed up and I swapped parts from the F-2 to get it running. I must have crossed the wires when I replaced the swapped out parts with new parts. I just never attempted to start the F-2 until I went to place it in storage.

 

Bob,

Its usually a case of "rectal-cranial" inversion that causes the gap to be a little close on spark plugs. At least in all the ones that I've done. Unless something is banging on each one then there's not really anyway they can close up on their own.
I'm betting someone, and I'm not going to mention any names here, but I think his initials are Bob Jones, might have had the wrong numbers in his head, or was disctracted by something else, or was slightly confused, etc when they put the plugs in last year.

Glad you were able to get it up and running
Bobby

 

Does your plug gapper have both metric and SAE dimensions imprinted, like mine??Were you wearing your glasses that day?LOL!

 

There is no way the pistons could be spanking the electrode unless the plugs were the wrong reach, or the head has been milled pretty excessively. Were the gaps uniformly wrong (same small gap)? If so, then I think either of the above responses are probably your answer.

 

All stock engine, nothing has ever been milled, at least not since I got the engine 30+ years ago.

I have the correct plugs, must have gapped them wrong last time but it still ran decent. I don't have a spark plug gapping tool small enough so I use a feeler gage.

I can tell you one thing, sure is a good feeling once you find the problem and the old girl fires right up, time after time. That old flat six is one heck of an engine. I've beat it pretty good at times but it just keep coming back for more.

 

If you set the gap and watch the plug all night I think you might see some shrinkage in the wee hours of the morning.

 

I would expect a little expansion in the morning, maybe not with such an old truck but maybe one that is 18-30 years old. Oh to be 20 again.

 

For reasons to numerous to mention .

 

Really should use a wire loop type plug gauge, feeler gauges can give an erronious reading. I've never seen a non electronic ignition engine that called for a gap that wasn't on a standard plug gauge. You probably have a "modern" gap measuring tool for electronic ignitions. You want one that covers .020-.050 gaps. I've always used a gauge that looks like a small jacknife, with wire gauge "blades" and a heavier piece with a slot that you hook on the vertical part of the side electrode and lever the electrode open. You close the gap by tapping the side electrode against a clean hard surface until the wire gauge fits thru the gap with a fair resistance when pulled across it.
According to the internet: 226 cu in 6 engine
Spark Plug Make: Champion H10
Spark Plug Gap, Inch: .030

That is a very common gap found on all gauges I've seen, such as this one: Craftsman 940816 - Craftsman Leaf Spark Plug Gap Wire Gauges - Overview - SummitRacing.com
Also check your DIY store around the gas powered lawn tool accessories for a tool, They still use spark plug gaps in the right range
Sure there isn't carbon or metal spray transfer buildup on the plug electrode closing the gap? Always file the electrodes on used plugs with a point file (thin flat fine cut file) before gapping, especially when using feeler gauges to set. File the center electrode until flat and smooth, File underside of side electrode until shiny with minimal pitting. When gapped underside of side electrode should be parallel to center electrode and end over the center or far edge of center electrode. If you cannot get this geometry at proper gap use a pliers style gapping tool or replace plug(s).

 

I think its a combination of the high compression put out by all the Ford Flatmotors and the cheap Chinese (See Jon Finn) sparkplugs found at the stores we are forced to deal with so that we can pay cheap prices.

 

I've been literally gapping plug for nearly 50 years. It probably was one of the first jobs my dad gave me when I starting walking and he was up to his neck into repairing cars in his auto repair business. I just used a feeler gage because I had a spark plug gapping tool for more modern cars that did have the smaller wires for older cars. I was sure I gapped them according what was stated in the shop manual. Some how must have screwed up.

I did buy a truck once with a 226 that started running like crap. I pulled the plugs and found plugs for an Oldsmobile were installed. The electrode closed up because the plugs were too long but the threads fit the head.

 

Sounds like a shameless plug for American made, lol.

 

Dick that there is funny!
Now be sure to use both hands when you stir.

 

Stir what?

 

Bob, I just have to say, you're the first person I've ever seen admit their vehicle did not "run when parked".