Chuck’s engine build thread!

WFarm said:

“Wisdom comes from experience. Great Wisdom comes from really ****** experience.”

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This and also “good judgment comes from experience and experience comes from bad judgement “.

Well, I give up. I’ve tried so hard to no avail today. It fires right up, but I have a miss that I cannot get rid of.

It cracked off first crank but had the miss from the get go. We stopped and checked compression, even 190 on every one, no low spots. We found a cracked plug wire, so I ran to town and replaced them all, and I had a distributor cap so I threw that on at the same time. Timing is well advanced but I bumped it forward a bit more and no change (not that I thought that it would be the issue.

I’ll check the rockers and lash, but I don’t think it would be the case if I have the same exact compression on each cylinder. I have a hard time thinking that I fouled a plug, they all looked pretty good and it had a miss from the very first revolution.

I’m done for now, I need to step away and get out of the garage for a while.

ChuckN said:

Well, I give up. I’ve tried so hard to no avail today. It fires right up, but I have a miss that I cannot get rid of.

It cracked off first crank but had the miss from the get go. We stopped and checked compression, even 190 on every one, no low spots. We found a cracked plug wire, so I ran to town and replaced them all, and I had a distributor cap so I threw that on at the same time. Timing is well advanced but I bumped it forward a bit more and no change (not that I thought that it would be the issue.

I’ll check the rockers and lash, but I don’t think it would be the case if I have the same exact compression on each cylinder. I have a hard time thinking that I fouled a plug, they all looked pretty good and it had a miss from the very first revolution.

I’m done for now, I need to step away and get out of the garage for a while.

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Probably a doa spark plug. New doesn't mean good anymore. Isolate the dead hole and replace that plug. Or play whack a mole and see if the miss changes holes.

My money (with everything else being right) is a bad plug.

Radiohead said:

Probably a doa spark plug. New doesn't mean good anymore. Isolate the dead hole and replace that plug. Or play whack a mole and see if the miss changes holes.

My money (with everything else being right) is a bad plug.

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Well, too early to tell, but after a little research, I’m my own worst enemy.

I’d read that aluminum heads need anti-seize for the plug threads. But first of all I didn’t know that you’re not supposed to use copper anti-seize. And if you use anything at all, it’s supposed to be a pinhead sized drop on the 3rd thread, no more. Well, in my usual “more is better “ line of thinking which is something I constantly battle against, I smeared it all over the threads.

But worst of all, NGK plugs have a trivalent coating for anti-seize properties and are specifically designed to be used dry. So that wasn’t helping either. (Of course that’s not readily available information and I didn’t know any of that).

So, I marked all the spark plug wires, pulled them off and pulled out the spark plugs this morning. Then I took one of the old plugs, and use it to clean all the threads out by running it in and out of the threads in the head until it came out clean.

I’m going for a bike ride with my friend this morning, I have new plugs on order that I’ll pick up after that. I’m not saying that’s the actual problem I have, but for now I’m going to plug my ears with bees wax and pretend that it was for my own sanity until I find out otherwise.

I’d pull the valve covers and give the valve train a once over.

When I put the engine back in my 76 and the first fire one of the pushrods dislodged itself, either #4 or #6. Didn’t bend the pushrod or damage anything, put it back in and relashed the valve and double checked everything and then proceeded with cam break in etc.

That was at the end of 2018 and that was the last time I’ve had the valve covers off of the truck and lot of miles since.

legopnuematic said:

I’d pull the valve covers and give the valve train a once over.

When I put the engine back in my 76 and the first fire one of the pushrods dislodged itself, either #4 or #6. Didn’t bend the pushrod or damage anything, put it back in and relashed the valve and double checked everything and then proceeded with cam break in etc.

That was at the end of 2018 and that was the last time I’ve had the valve covers off of the truck and lot of miles since.

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Maybe you’re right- engine is dead solid quiet though, and I’ve got even compression everywhere- if that were the case and I had something off with the valvetrain, wouldn’t that show up on the compression? Not against checking anything though.

In my scenario above, no noise other than the miss.

If it was an exhaust pushrod, the intake is still opening and able to fill the cylinder with an air charge, still creating compression.

Also put a vacuum gauge on it, that will provide some insight too. Could even be an intake gasket leak.

legopnuematic said:

In my scenario above, no noise other than the miss.

If it was an exhaust pushrod, the intake is still opening and able to fill the cylinder with an air charge, still creating compression.

Also put a vacuum gauge on it, that will provide some insight too. Could even be an intake gasket leak.

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Really! That’s interesting. I’d have thought that it would be popping out the intake. I’ll take a look today.