Rebuilding the 4.3L V6 and distributor questions

FriendlyMan

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Last two paragraphs for the important stuff.

A friend of mine has a 1997 GMC Jimmy with a 4.3L V6 with somewhere around 160,000 miles on it. This summer we've been working on it together and trying our best to get it up and running. It had been sitting and hadn't been run for many months, probably around a year or more. I figured since I had a few weeks off I might be able to help out. I have a little experience working on vehicles and also thought it would be a really fun learning project, he agreed.

On the first afternoon we set out on our adventure and cleaned the leaves off of it and cleaned up the outside a bit. On our first attempt at starting it the battery was dead, so we let it charge up overnight (and it still surprisingly holds a charge!).

The following day we put new gas in it and some fuel cleaner I had picked up for about $5. We started it up and got it running, but after about 10-15 minutes or so it would overheat, choke up, and die. After some research and some more tests, we had come to the conclusion that the head gaskets were blown (and probably a dead water pump). We had found water leaking out of the tail pipe and evidence that the coolant was mixing with the oil, as the oil was a bright milky color.

So my inexperienced with replacing head gaskets self said what the hell, we can accomplish it in 2 days. I was wrong. Being limited on tools and money, we spent quite a lot of time researching, cleaning and scraping the mating surfaces of the heads, block, intake manifold, and bolts (damn things had so much lock-tight on them! We wire brushed all of those damn head bolts for hours). We didn't take the engine out, and man it was tough carefully replacing those gaskets. Dis-assembly took just as long as reassembling the engine and that took just as long as cleaning them up! We labeled everything we took off and took lots of pictures throughout the disassembly so we knew where everything went. We watched a lot of youtube videos, read lots of how-to sites, and read quite a lot of the Haynes manual for the vehicle.

We completely reassembled the engine and replaced both the head gaskets and intake manifold gaskets, all total including the torque wrenches we bought for the job came to about $175.00 plus a weeks worth of work. Other things we bought were oil, sealant, the Haynes book, etc.

The story gets a little sad though. After we spent many days cleaning the mating surfaces of the main engine components I made a disheartening discovery. I was looking over the block before I was going to head out that night. And there it was, a big internal crack in the block. I told my buddy that that's that, man. Not much we can do without getting it welded or worked on by a professional, and it would probably be better to just chunk it and buy a new one. Having it worked on was not much of an option, it was going to be scrapped anyway. That was part of our motivation on this educational project.

But, as we planned, if we did find something like this, we had decided to reassemble the engine anyway just as it was. Because in the end we'd have learned a whole lot anyway, so why not. Before we decided to reassemble the engine though, we decided to just try and JB weld the crack. I sanded the surface surrounding the crack, sprayed it real good with brake cleaner, and used an air compressor to blow out everything in the crack. Than we filled it up with JB weld. On the internal side where the coolant was leaking in the oil, we put a good layer of JB weld on it (on top of where I sanded) that was about 3-4 inches long, 1.5-2 inches wide. I double JB welded it.

So now we have the engine entirely reassembled. The problem we're having now is that the distributor timing is off (from what I hypothesize). The Haynes manual only says "mark it properly when you take it off." Unfortunately, we did not make this mark. I'm looking for any kind of wisdom on how we can properly configure the distributor's timing. Our plan is to find top dead center of cylinder 1, hopefully there's a mark marking 0 degrees on the crank shaft pully (I haven't looked yet) and try to fit the distributor in so that it points towards cylinder 1 as the manual says.

I think I can accomplish this by rotating the shaft until I get some compression felt at the 1st spark plug hole and moving the crank shaft so that notch lines up with its mark (correct me if I'm wrong) and carefully trying to insert the distributor to proper alignment. I don't know how I can rotate that oil pump shaft, as I don't have any long screw drivers. If anyone has any experience, suggestions, or wisdom in doing this please let us know.

Also, has anyone had any luck with JB welding an internal crack in the block?
 


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