For Palm Readers and Spark Plug readers

[jd52cranbrook]

Had a miss in my car intermittently over the weekend going to the dirt track races (45 miles, 80 degrees) while climbing a medium grade hill. Found this plug out of number three hole. Compression is still good in it, put in another plug and was on my way. Bad plug?, or a hint of things to come?

[Niel Hoback]

If the other 5 are alright, and you didn't hear any serious pinging, I'll bet its just a lousy plug. Keep an eye on the new one until your comfortable with it. Keep an ear on it too.

[Reg Evans]

It appears that the electrode fell out of the center of the plug. Hope it made it out the exhaust OK.

[Joe Flanagan]

jd52, your mission, if you choose to accept it, is to crawl back over the 45 miles on hands and knees to see if you can find that electrode.

[jd52cranbrook]

I'm going to say the Road God ate it for a sacrifice and call it good.

[Joe Flanagan]

Out of sight, out of mind. Out of hearing is good, too.

[martybose]

The good news is that there don't seem to be any flecks of aluminum on the remains of the sparkplug, so it probably didn't detonate itself to death.

Marty

[greg g]

If you know anybody with one of those lighted boro scopes, pulling the plug, inserting the scope, and having a look at the top of the piston and the valves might be a good idea.

[jd52cranbrook]

Thanks, but I don't know of anyone off hand who has one.

I did drive it over Sunol Pass, turned around and came right back the next day, which was a hotter part of the day then before. No problems both up and back in fifth gear. I will pull it once a week or so to check it out, but I am hoping its a fluke.

[Flatie46]

I'm never that lucky! If it'd been me that electrode would have jumped between the valve and seat as soon as it fell out. You need to go buy a lottery ticket.

[jd52cranbrook]

With all the weird things I have experienced with this car on my travels, I am due a break or two.

[jd52cranbrook]

But I do have questions, that I am not sure I want the answer on another issue with plugs. I will take pics tomorrow when I pull them and show ya......

[Don Coatney]

My Briggs engine 30 seconds after a small roll pin made its way into the combustion chamber.

[Joe Flanagan]

Don, I'm sorry for your Briggs, but that is a museum piece. Fascinating. You can see how many times the pin got slammed before it finally blew through.

[Don Coatney]

Don, I'm sorry for your Briggs, but that is a museum piece. Fascinating. You can see how many times the pin got slammed before it finally blew through.

I was really lucky that the pin made it past the intake valve in the split second it was open with no damage to the valve. I installed a new piston and a new head and the briggs now runs like new.

[jd52cranbrook]

Plugs are lined up left to right, 1 through 6.

Note numbers 5 and 6.

I am running dual intake, dual carter weber carbs.

It would seem to me if it were the carb running rich I would see it on the 4th plug also. The valves in 5 and 6 were set a little looser than the rest, my engine builder said they needed it because they run the hottest.

Swapping carbs is a option to try, but I think its the valves.

Any ideas?

[Don Coatney]

Plug gap looks very wide?

[jd52cranbrook]

I've been changing it up and down to look for a difference. Has not changed anything. These are set at Langsdon's recommendation. I usually run smaller.

[greg g]

What is the compression on the rear two cylinders. Seems to me that if it was carb related that #3 would look very similar.

Detonation can also wipe out a center electrode, so it may not have borken it may have melted.

[Joe Flanagan]

Guess who's pulling his 5 and 6 spark plugs this afternoon.

[Don Coatney]

Is your intake manifold common (no baffels) to all 6 cylinders? Is your carburetor linkage balanced? I believe blueskies fabricated a device to use the flow meter to balance his linkage. Any difference in the air filters on your carburetors? I found that my plugs would fowl with a single air filter element on my B&B's. So I doubled up and stacked them to fix the problem.

[jd52cranbrook]

Yes, I have balance carbs, I use the unisom (sp) with plumbing fittings to get a good fit over the carbs.

The plug that had the bad tip was out of a different cylinder, these two black ones are 5 and 6.

I am running auto lite 306s, The auto lite site says I either need to go to a hotter plug, 308, or my choke could be out of adjustment.

But I still feel I would see something close to similar out of the fourth plug if the carb was acting up.

Anyway, I have two 308 plugs coming tomorrow, will run them local a few days and see what I find.

Interesting read about spark plugs. There is lots of info on the different manufacturer's site.

[jd52cranbrook]

Also,,, runing a offy dual carb intake, I would assume it would be uniform throughout the chambers.

K&N air filters, due for cleaning, will add to my list too.

Compression is 5=150, 6=155

Edited June 30, 2010 by jd52cranbrook

[Tom Skinner]

JD52,

This may sound ignorant but would a Champion Plug suit your engine better?

Autolites tend to be a cooler burning plug. Champions hotter burning.

I have no Idea about the dual Carburetor set up so I may just be grasping at straws here.

Tom

[jd52cranbrook]

You might be right Tom. But I just picked up these two autolites. Will try them first, plus make sure my choke is shutting down correctly, but I think that part is ok.