What did you do this weekend?

Some of this happened last weekend, some happened this weekend, I didn't update last weekend because last Monday as I sat down to make the weekly update I hear my wife yelling from the kitchen as I find out that my plumbing exploded. So I've been working on that instead and you can expect this update to be twice as long because of it. To see the last actual update on the engine build go here.

Last time we talked I mentioned that the piston rings I ordered didn't fit the pistons I have, so while the process is the same, the pictures are a mix of the old rings and new. I apologize in advance if you're offended by continuity errors. I know you're thinking "Oh great and wonderous infallible wizard of the automotive world Augustus, how could it be possible you had the wrong part?" and I'll answer that as 'maybe it's my fault, maybe it's not'. Come with me on a small tale of Original Equipment Manufacturer (OEM) vs Aftermarket Stock Replacement (ASR) and minimizing the replacement parts kept in stock...

While waiting for the valve shims to arrive, and before knowing the piston rings wouldn't work, let's turn our attention to the crankshaft bearings. Remove the crankshaft rear main housing and replace the seal. Pop off the main bearing caps and inspect them along with the other half of the bearings still in the block, find that the number 3 bearing has seen better days. The engine block and crankshaft are iron and steel respectively, the bearings are aluminum so the softer metal can take the abuse should things go awry (good bearings), and awry they did (bad bearings). The state of the middle bearing is indicative that the shortblock was run low on oil for a period of time, a "I know I have an oil leak so I just top it up when the oil light comes on" sort of low. That is if the car even had a low oil light and if not probably only topped up when the oil was changed. On the upside the bearings took the abuse, did what they were supposed to do and protected the expensive parts by being a cheap sacrifice, and this is why you always check everything in a donor engine. The bearing surfaces on the crank, caps, and block are fine. They have no scoring, just some burnt oil stains, nothing that you can even feel. So I cleaned them up, applied assembly lube to everything, put in the new crank and thrust bearings, and torqued everything to spec.

Moving on to the piston rings (and acting like we had the right ones all along), rod bearings, and installing the pistons in the block. Start at the bottom with the oil control ring and work your way up. The oil control ring holds onto and distributes oil to the bore via capillary action in the perforations of the ring and is the easiest to put on as it's held together with a wire spring and then held in place with two thin rings on top and bottom. The first and second rings are compression rings that do the work to keep the cylinder centered and keep the combustion above the piston. These rings have little marks to tell you which way is the topside, so keep an eye out for correct orientation and be sure to spin them so the gaps are not aligned with one another. They are make of ductile iron and chromed steel and much stiffer, but go on with some added effort. There's a proper tool to put them in place, but that just seems unnecessary for a garage mechanic that doesn't replace piston rings daily or even weekly. You can marvel at how incredibly flat the rings are as without any oil on them they experience wringing. But before you put them on the pistons, like everything else in engine building, you need to check their clearances, known as end gap, by placing them inside the bore, pushing them down so they're even/flat, and using your feeler gauge to measure the distance between the ends. Checking the gap on piston rings is much easier than valve shims as you just need to make sure the gap is larger than the minimum and smaller than the maximum. If the gap is too small you file off a little of the end of the ring, if too large you order new rings as the ones you have are out of spec. These were all fine thankfully.

Now we replace the bearings in the rod (where it connects to the crank) and put the pistons in the block. First rotate the crankshaft so the pistons would be at the bottom of their stroke, put the pistons in a piston ring compressor, ensure they're facing the correct direction, put them in the block rod end first, then tap them down with a soft mallet. Once in the bore, which you've lubricated, push them all the way down onto the crank (and do the same to the other piston(s) that are at the same bottom of their stroke), turn the engine over, and put on the rod caps. Turn the crankshaft 180 degrees and do the same with the other two pistons. Once all are in place, torque the rod bolts to spec and turn the crankshaft to ensure there's no binding or unexpected drag that would indicate and issue/screw up. Rejoice, onto the head!

We finish up the head by placing the new valve shims in the correct spots to get the clearances correct for the cams and it's ready to bolt to the block. Simple! Well simple because the cams have to be out of the way for you to torque the head down to the block, so the head gets "finished" later. As for bolting it to the block you can reuse the stock bolts or you and switch over to studs. Studs have the advantage of making it easier to guide the head in place without shifting the gasket and provide better/more consistent sealing by reducing the factors that lead to improper torque readings. I'm using studs for those advantages, the fact that I've upped the compression higher than stock, and because I got the studs for cheap ages ago. Sort the studs to find the four short ones, four long ones, and one middle child and thread them hand tight into the block at the correct positions using thread lube to keep from getting false torque readings. Then check your head gasket just to be sure all is well and find that it isn't.

Remember how I said way back in Timasomo threads that while these parts fit together they weren't necessarily ever engineered to do so? This is where one of those factors comes up. The holes and crescent shaped cavities around the bores in the block allow oil and coolant (separately) to flow from the block into the head and back to the oil pan/radiator. The block was not meant to have this head on it, so there are three spots where the head gasket doesn't line up with the block. The top two small ports aren't much of a concern because 1. they're so far from the coolant passages that it'd be a big deal to remove enough material to line them up, 2. they're so small that it isn't losing all that much flow not using them, and 3. that side of the head is the exhaust side that has very small passages for coolant anyway so I don't think it'll make much of a difference. Now the larger hole on the bottom is an issue that I want to resolve. It's close enough that drilling it out a bit is easy enough, the coolant passages on that side are sizeable and shared between cylinders 1 & 2 and 3 & 4 respectively with a seagull shape, and leaving this one blocked would undoubtedly cause a hot spot around cylinder 2 that I do not want. So I drilled it out, took a bad picture, and then cleaned it up more before bolting the head down.

Bolting the head down is pretty simple, apply thread lubricant, guide the head onto the block with the head gasket in between them, carefully put the washers and nuts on the studs in the tiny amount of space you have so you don't drop them under the valve springs and have to fish them out, then torque to spec in multiple passes in the prescribed order. Afterward put the cams in place, apply a little form in place gasket (FIPG) the the end caps, and torque to spec yadda yadda yadda. Then insert the cam seals onto the ends of the camshafts being very careful to do so evenly so you don't mar the lip of the seal after putting NLGI number 2 multipurpose grease on the inside and assembly lube on the outside, press in completely. There's a special tool for this as well, but I don't have it, I still haven't finished the upgrades on my 3D printer to make one, and it can be done without it so long as you're patient.

Next up refresh the gaskets and brush off the corrosion/scaling in/on the water pump before replacing the water pump seal, being sure to get that last little bit of stuck on o-ring out of the groove, and sort through the unorganized bag of bolts taken off the engine as present you cusses past you for not bagging and labeling everything like you know you should while telling yourself "that's future me's problem". Thankfully you've done this to yourself enough that you can figure out what goes where. Find one bolt that has rust on it that was obviously the water pump outlet bolt that met the engine's leaking water pump and pick up a replacement bolt. Not because that one won't work as the rusted threads are on the outside of the block, but just because you don't want the rusted bolt; torque to spec. Then open the oil pump, add assembly lube so it's not running dry the first time you start the engine, and put it back together. Sandwich the oil pump gasket (not this one, because it's the wrong one and you ordered the right one but didn't take a picture) between the pump and block and torque to spec. Take photo that looks weird because the engine was upside down when you did this.

On to next issue when mixing parts from different engines. For this car the transmission front differential sits underneath the engine, as a result you have to use the oil pan from the original engine as no other factory oil pan will clear the transmission. The issue with this is the factory oil pan is pretty much a perfect rectangle with straight sides, but this block has this little indentation that makes it no longer rectangular. You need to bridge this gap and in my case it's done via an oil pan adapter plate. Problem with the oil pan adapter plate is it also has clearance issues and the number 3 rod hits the adapter when you turn the crankshaft. So need to blindly mark out the bottom side of the adapter by tracing a marker against the block, do the top side as well just to be safe by eyeballing where the rod wants to be, then grab your die grinder and remove the offending area. It's not pretty and you probably took a little too much, but it'll work fine. Then it's time to address issues with the oil pan itself.

For one the oil pan has one bolt that doesn't line up, so widen that hole as well since you have your die grinder out (and realize it was the wrong tool for the job and you should have used a larger bit or a drill) until the bolt will clear. Next up is fixing the fact that the new larger engine you have has a longer stroke, so the rods are going deeper into the oil pan and rod number 4 will hit the oil pan as it spins. No bueno, so the order of business is the incredibly high tech world of the 5lb mini-sledgehammer to make room until the rod does clear. At this point you've realized the new stainless steel oil pan bolts you ordered are too long because you based your measurement off the wrong bolts, so time to do some sanding on the valve covers to prep for paint (that you still haven't done because it's too cold for the special wrinkle finish paint and yet was warm enough today, but you've been dealing with plumbers and work so will do so tomorrow you tell yourself) and grinding off the rust and old paint from the oil pan before painting it with new rust preventative paint.

All done making two weeks worth of posts in a single comment? Have you made other people have to scroll really freaking far to see any comments that might be below yours? Are you now arguing with yourself if you want to use oil pan studs instead of bolts since you ordered the wrong ones? If yes to all these questions, then hit "Post comment" and go read what others have posted in the hours you've spent typing all of this up without proofreading it. Oh and add random photos like the $600 Datsun 260Z you moved to your friend's house from the middle of the night saga a few weeks back, the last photo of the bottom of the block before you snapped a bolt off in one of the oil pan holes while chasing the threads and so now you have a single SAE bolt that'll be there forever to remind you of your screwup since you royally messed up that hole trying to get the old bolt out and repeatedly breaking drill bits in the process. Not to mention reading the tap wrong so you used an unnecessarily fine thread tap and not just stopping what you were doing to go buy metric taps instead of just pushing forward with the inherited SAE taps you had.