You cant keep a good 82 down !!!!

[rlux4]

Why didn't we think of that? Of course; counter guy sold you the wrong plugs, gap got closed. Duh! Talk about not seeing the forest for the trees.
I couldn't be happier for you.
WooHoo!!!
Ron

[BEEK]

just wondering what spark plug they sent you. if i may have the number, i would like to do a little research, secondly, does your engine have high compression pistons?

[kmac33]

Craig,
Very glad to hear that it was such a simple solution .

[ventura ace]

Glad to hear that you found the problem, Craig . . . . but I'm really puzzled about those spark plugs getting hit by the pistons. There was another thread recently, where a member here thought the plugs were hitting pistons, so it struck my curiosity to look at my engine (which is apart), to see how much clearance there would normally be between the piston and the plug. I can't remember the exact numbers that I measured, but there was about a mile of clearance, and I have tall 8mm domed pistons. I'm going to check again tonight, because I'm curious. I'm thinking that there was more than 3/4" between the face of the head (including head gasket) and the tip of the spark plug electrode.

Do me a favor, Craig and measure one of the bad plugs from the tip of the electrode to the sealing crush ring on the spark plug. I'd like to compare that to the length of the correct plugs. I'll get an accurate measurement of the dimensions on the head tonight. It's a 2L head.

Alvon

[BEEK]

Glad to hear that you found the problem, Craig . . . . but I'm really puzzled about those spark plugs getting hit by the pistons. There was another thread recently, where a member here thought the plugs were hitting pistons, so it struck my curiosity to look at my engine (which is apart), to see how much clearance there would normally be between the piston and the plug. I can't remember the exact numbers that I measured, but there was about a mile of clearance, and I have tall 8mm domed pistons. I'm going to check again tonight, because I'm curious. I'm thinking that there was more than 3/4" between the face of the head (including head gasket) and the tip of the spark plug electrode.

Do me a favor, Craig and measure one of the bad plugs from the tip of the electrode to the sealing crush ring on the spark plug. I'd like to compare that to the length of the correct plugs. I'll get an accurate measurement of the dimensions on the head tonight. It's a 2L head.

Alvon

this is the same thing im wanting to work on as well

[ventura ace]

this is the same thing im wanting to work on as well

Good, we can compare numbers!

A

[4babycar]

Voila! I bet the coffee tastes better, the sun shines brighter and all those little things that seemed so gigantic yesterday have gone back to their proper importance. Speaking of which, now that you have a fun car to go to the parts store with you should consider keeping and re-building the 76. I know you are concerned it will sit and not get done but how about if we all sign up to spend rotating weekend days in God's country helping. I mean just look at what you learned in a short visit to your mechanic friend yesterday. think how much an engine rebuild will teach you!

Count me in!

[So Cal Mark]

my bet is that the plug came crushed shut. I've looked at that space and Alvon is right, there is a mile of clearance

[ga.spyder]

Hey guys,
Those are pretty good points re. clearance.I went by the shop today,and Gary mentioned the same thing after thinking on it.Is it possible it came closed?...I would say no.I did gap them.Is it possible that I did it myself somehow?Absolutely.I swapped plugs around 1 time,but it was before I isolated the dead cylinder as #4.I could have had a closed plug in one of the other cylinders and moved it into #4 I will get the numbers and measure the length when the plugs are back(car is at the shop awaiting new oil pan install.Thanks for all the help and concern,and I will post my findings.
I drove the car today and it seems to be running fine,no signs of the miss(knock on wood!)

[jimincalif]

You did check it for something rattling around loose in #4?

[ga.spyder]

Yes Jim,we did.We took a fiber optic camera and searched it ,and the other 3 cylinders for a sign of debris or damage.A little carbon discoloration,but that was it.After talking with my friend and the posts by some of the experts here,I am 99% sure it was something I did. The best move I made was to let a pro and a couple fresh set of eyes have the car.I had done so much pulling of parts that I was losing track!!

[ventura ace]

After checking some measurements on a 2L head tonight, my conclusion is that it is very unlikely that you had contact between a spark plug and piston on your 2L engine.

0.910": from shoulder of crush washer to tip of electrode, NGK BPR7ES and BPR6ES spark plugs
0.632": from tip of installed spark plug to face of cyinder head, including standard head gasket resting on head.
0.315": from top of block to top of 8mm domed pistons (crown of piston is flush with top of block)

This is about the tallest piston you'll find for these engines -- yours may not have any dome if they are standard pistons, and the pistons may not even reach the top of the block at TDC. So, even with the tallest piston, you would have about 0.632 - 0.315 = 0.317" clearance with the NGK spark plugs listed above.

And, if the spark plugs are indeed longer than the 0.910" dimension for the NGK plugs, the plug would be bumped by the valves before it would be bumped by the piston. For this cylinder head, it looks like the electrode of the spark plug could bump the intake valve if the spark plug was about 0.150" - 0.180" longer, and depending on which way the electode was pointed.

My guess is that the spark plugs were bungled by handling, unless the plugs are >1.1" long from electrode to crush washer, in which case they may have tangled with your valves. It's really easy to bend the soft electrodes from just dropping a plug onto a hard surface from 1 or 2".

Glad to know you have it running good now, here's hoping you get renewed energy to get the 76 figured out!

Alvon

[ga.spyder]

I agree that it was operator error,resulting in the closed plug.The Autolite plugs that came out were slightly longer than the NGK's that we put in.But definitely not enough to make contact.Guilty as charged.I will get some exact measurements when the car comes home.My apologies to the pimple-faced kid at Autozone ,that always asks''A what''?
I worked at the shop today ,on their roof.I went to drive the car w/ the new plugs,and it didnt want to start.OMG...not again.The old mag p/u wires had been a little frayed and must have gotten into the rotor part.The new part(which I had removed ) solved that.I really need to retrace and put all the new parts back and check every connection,etc...