Complete Misfire on Three Cylinders

[Zed Head]

3 hours ago, Captain Obvious said:

So here's a question for today. If you look closely at this water jacket hole... Up by the timing chain and cylinder one, on the left side of the engine. It's threaded.

The paper towel wad is stuffed into the head bolt hole, and the other hole just goes down into the water jacket. There's a corresponding hole in the gasket and the head. but question is... Why is it threaded?  :

It's a performance modification, adding an extra head bolt.  The PO is actually an expert in Z engines.

[Captain Obvious]

Actually I'm pretty sure those threads are stock from the factory. First off, they are straight and not at some screwed up angle, so I doubt that my PO did it. And second, that same hole is threaded on my F54 block, and I don't think that engine has ever been apart until I did it.

And interestingly enough, the water jacket hole at the rear of both blocks on the same (left) side is threaded as well.

10 hours ago, Patcon said:

Sometimes people will block holes like that to change or restrict water flow.

That's exactly what I was thinking, and actually, why I asked. I've been looking into head gaskets and the 83 gasket uses a smaller hole there than the previous versions. I was thinking I could run a restrictor plug into that threaded hole.

[Patcon]

5 minutes ago, Captain Obvious said:

Actually I'm pretty sure those threads are stock from the factory. First off, they are straight and not at some screwed up angle, so I doubt that my PO did it. And second, that same hole is threaded on my F54 block, and I don't think that engine has ever been apart until I did it.

And interestingly enough, the water jacket hole at the rear of both blocks on the same (left) side is threaded as well.

That's exactly what I was thinking, and actually, why I asked. I've been looking into head gaskets and the 83 gasket uses a smaller hole there than the previous versions. I was thinking I could run a restrictor plug into that threaded hole.

I know this is used sometimes in water jackets and in oil lines sometimes but I don't know enough to speak to when to do it and why.

[Zed Head]

30 minutes ago, Captain Obvious said:

Actually I'm pretty sure those threads are stock from the factory. First off, they are straight and not at some screwed up angle, so I doubt that my PO did it. And second, that same hole is threaded on my F54 block, and I don't think that engine has ever been apart until I did it.

Might be for assembly in the factory or servicing.  A lifting bracket might install there.

[Captain Obvious]

So I'm still waiting for alignment dowels and head gasket to get here.

In the meantime, I spent a little time cleaning up the header surfaces where they mate with the head. My PO put on a 6 to 2 header of unknown origin. No idea where he got it. So I'm looking it over and see huge welding goobers inside the tubes and pieces of MIG wire stuck in there from where the guy who welded it got the wire stuck and burned off pieces of it.

Here's the worst. About an inch of wire stuck in there:

I pried it up with a screwdriver:

And pulled it out with a pair of pliers:

And there are other testaments to the workmanship, like this huge goober. It was on the upper side, so I used a little mirror to get a good pic. I stuffed a paper towel down the pipe a little and tried to pry it loose. No joy. I'm leaving it in there:

So today's question(s) is... What welder has so little pride in his work that he'll leave junk like that in there? Is it just me? Are my expectations too high?

[Mark Maras]

The mark of a true Craftsman is one who cares about quality more than time and money. Are your expectations too high? Not at all. I suspect that the PO or his mechanic had never done quality work and didn't understand the concept of Craftsmanship and pride in a job well done.

[Captain Obvious]

On ‎7‎/‎27‎/‎2019 at 9:30 PM, 240260280 said:

I've seen numbers on the block and on pistons. I think it was how they selected best fits in plant.

I found the numbers on the block. Here's where the "34" pistons live. I got five of these:

 And I got one of these. This is where the "45" piston lives:

I haven't measured the bores to try to figure out a correlation between the actual numbers and the measurements. It's another of those, "because then I would know" issues. 

The "STD" piston lives in one of the number three marked cylinders. I have no doubt it's aftermarket installed by my PO, but I don't know why. No idea what happened that necessitated replacement of one piston. But I do know that the block wasn't bored.

[jonathanrussell]

Do the valves that correspond with the piston you think was replaced look different from the other valves? Maybe a valvetrain issue caused a collision...which caused the head to get worked on but not really rebuilt?

[240260280]

3 hours ago, Captain Obvious said:

I found the numbers on the block. Here's where the "34" pistons live. I got five of these:

 And I got one of these. This is where the "45" piston lives:

Good.... I was starting to doubt my memory.

[Captain Obvious]

5 hours ago, jonathanrussell said:

Do the valves that correspond with the piston you think was replaced look different from the other valves?

Nope. They all looked like arse. The only one that stood out from the rest was an exhaust valve from a different cylinder. That one looked like bent arse.

Of course, there's no telling if my PO swapped the pistons around. Based on the fact that the "45" piston is in the bore marked "4", I don't think so, but at this point, who knows!!  

[Captain Obvious]

It's alive!!!!!!!

I ran a compression test before I started it (so it was stone cold) and the highest cylinder was 175 and the lowest was 160. The max differential between any two adjacent cylinders was 10 psi. After all the crap I found wrong done to that engine, I'm pretty happy with that.

I have all the valves set a little loose because I'm thinking they might tighten up a little bit over the first batch of miles as everything beds in. I don't want any of them hanging open, so I set all of them (intakes and exhaust) to .011 cold.

The plug into the water jacket seems to be holding, and it sure is nice to be able to tighten down all the bolts on the valve cover down and have it not seep oil. That's a new one for me with this car!

Might just be wishful thinking, but my oil pressure seems a little higher. I'm thinking that since it's not gushing out the seam between the cam tower bearing and the head anymore and actually feeding the cam bearing. @jonathanrussell the cam seems to be quite happy in it's new home!!! So far, so good!

I'm gonna drive it for a couple days and then give everything a once over to see how it's doing. Pull the valve cover and see if I'm wiping any lobes off. Check the lash. Change the oil. Do another compression test. I forgot to pick up new plugs too, so I reused the old ones. I'll pull them and see how they look, but I'm not sure it'll be an accurate representation. I'll replace them soon.

So, about the only thing that I'm worried about is I don't think the exhaust header is sealing properly. Stupid header. Not sure if it's a gasket quality issue, or a header quality issue. My copper nuts worked out great, but didn't make it seal.

[rcb280z]

10 minutes ago, Captain Obvious said:

I have all the valves set a little loose 

I may be way off here but will this create a lower compression reading? 

Edited August 12, 2019 by rcb280z