1991 Top End Rebuild

Hey there, First let me start with a quick history of the truck...

I bought it about 2 months ago, and it wasn't running at the time. It had been sitting on blocks for 7 years without being run once, but was parked in good condition, with only 152 000km.

I payed $900, and went out to buy a fuel pump, and got her running. I drove it across the country, 5000km in total. Had to replace the thermostat 3500km into the trip when I realized it was stuck open... should have done it earlier i know.

About half way into the trip the engine started getting a rumble to it, and the previously smooth exhaust stream was now sputtering. Most notable at idle, but present in the entire rpm range.

My exhaust smells sweet, and although there isn't much smoke, some is present at startup. There are no bubbles in my radiator overflow, but the coolant is being contaminated with oil.

So yesterday I began my top end rebuild...

Most everything came off smoothly, although I did break 2 or 3 exhaust studs, which is a real PIA because my local Canadian Tire doesn't even have the part listed. I guess I'll grabe some grade 8 (right?) studs from the hardware store.

The gasket material is seriously stuck onto the heads, cleaning it is proving to be a nightmare. I can't find an obvious cause of the coolant leak from the head gasket, but all around it looks pretty burned. Gonna clean er till she's shining cause I'm kind of OCD like that... If I was smarter (and by smarter I mean less broke) I would have the heads resurfaced, but that's just not an option at this point.

The inside of the intake manifold is quite oily, and I'm wondering what the cause would be. The PCV valve is confirmed to be functional, although I purchased a new one to replace it anyways. I'm thinking it's either blow by, or some egr issue. I am admittedly unfamiliar with egr systems. I learned everything I know about cars from rebuilding my '76 MGB, so EFI and EGR are both new to me.

I noticed that it has roller rockers as well, is this stock? or has this motor been upgraded? I did notice that there were no exhaust gaskets at all, just metal on metal, so it has been opened up by someone I guess.

So I'm still at it. Been taking my sweet time. Just started lapping the valves from the second block. The first one is all lapped. Once I'm done I'll clean out the ports and coolant channels.

There is a large amount of pitting on all of the exhaust valves, and some seats, lapping them is much more time consuming than the intakes.

I am also doing the valve stem seals, as I in there anyways. They look like their in good shape, but a few definitely didn't have a snug fit anymore.

Hope to get her done tomorrow, so I better get cleaning. Sill have to do the surfaces on the block.

This thing is now a giant PIA. I get everything apart and off the car in nearly 3 hours. Now I've been at it for a week and still haven't finished. This should have been 3 days tops of decent pace work.

Took me forever to lap the valves, like a couple days lol. They were <b>really</b> bad, and pitted extensively, even on the actual seats.

The longest thing I have been dealing with however (now my fourth day god help me) is removing those bloody exhaust studs. I can't even begin to explain the frustration this has caused me. My other vehicle is without insurance as it is a summer roadster, so I've been relying on the availability of a couple of friends to get me parts, which sure doesn't make things faster. I've completely destroyed all of my drill bits in the process, and have made at least 3 different trips just for more drill bits (Yes I am using cobalt bits).

The trouble began when I decided to try to retain the existing thread size by drilling the stud and putting in those reverse tap extracters. The stud drilled fairly easily with the cobalt bits, but then I put in an extractor bit that was probably to small (why do I take these "shortcuts"?). Tried to crank it out and BAM, I snapped it off in the stud. It broke right at the end of the stud, and the backside was all the way to the end of the stud, but no space to grip. The only option was to drill it out. Unfortunately it is nearly impossible to drill those bloody things. Hardened steel and all. went through $30 worth of cobalt bits just to get that one drilled, and a day and a half of mucking around. I then drilled it out as much as I could, and put in a much larger extractor bit. BAM... same damn thing... another day later and I got it out. I drilled it out larger, with a 1/4" bit, but I managed to wreck the threads on one side.

I then moved on to the second of three, and foolishly attempted a better set of extractors....BAM... same thing... another day and more drill bits later and I had drilled out the stud, and wrecked the threads again, a 1/4" is just too big, no room for error.

So I think I've learned my lesson .

Now I've got another stud to drill, which actually won't be hard assuming I don't try to shove hardened steel in there.

I decided to do this right, but after failing to retain the original threads I had to make a decision. I could just tap them to the next size up, but then I couldn't use the same size bolts, would have to drill the manifold, and it would just bother me. I decided to go out and buy a heli coil kit. I'm about to drill em out and try these for the first time. Wish me luck.

Canadian Tire "bolt extractors" are a joke. They are actually "screw" extractors and don't work at all on hardened steel.

Did you try heating up the manifold after applying generous quantities of something like WD40 (make sure to have some wet rags around to toss on them if they ignite)? Heat helps loosen things up when the metal expands.

It is also best to heat them up before you try to remove them. Running the engine before extracting exhaust manifold bolts usually helps...for future reference.