I’ll start with questions before background since this is likely to be a bit wordy:
First, If a cylinder that is misshapen is honed and new rings are installed, are the new rings likely to create as good a seat as not honing/replacing the old pairing?
So now you all get the title of this thread. Here’s the purpose, my wife and I are students. She’ll be graduating in about 10 months, I’ll be graduating in about 13 months. If her car can survive until then, we can take on a car payment. If it can’t, we’re screwed. After measuring compression on her engine, a 1zzfe in a 2001 Toyota Celica GT (nominal 218 psi, minimum 145 psi, max difference 15 psi), I wound up with figures something like cyl 4 - 215psi, cyl 3 - 100psi, cyl 2 - 50psi, cyl 1 - 180psi. There was no oil in the coolant but coolant was just disappearing, same with oil. No apparent leaks. I figured head gasket and dove into a top end rebuild. In a momentary lapse of judgment and an opportunity to pick up reputable parts for surprisingly cheap, my concern that the rings could also be burnt out lead me to go ahead with a bottom end rebuild too.
The head gasket’s seal certainly was a problem, though not because of the gasket itself. Both the head and block are out of spec, with the deck resembling a bowl shape and the head resembling a taco shape, allowing a bunch of room between cylinders 2 and 3. The block is just over the .002 tolerance. The head is way over, I’m not sure it can be resurfaced. Meanwhile, the tolerance in the cylinders is .0008. I don’t have (read:can’t afford) tools to measure with that kind of accuracy, and even with what I have I’ve managed to determine that the cylinders are out of spec, there is at least a .003 variation. To do this right, I should probably replace the head and bore the cylinders (read: replace the entire engine because it’s not worth it). But the car also has issues with the wire harness (speedo and tach work intermittantly, OBD II com doesn’t work at all) and has occasional hard shifts from the transmission, which means the whole car is a mess. Either way, I’m sure if I do get the head gasket seating well, the rounded cylinders are going to cause more problems than they did before because now there’s more pressure on the rings, which is the other factor I’m considering and the reason for all the background info. I’m not sure that the old rings (near 300,000 miles) will put up with much more time, let alone more force plus more time.
But, back to being students. Boring the block then buying pistons, and another set of new rings is going to add another $300 or so. All of this on top of needing at least an attempt at resurfacing the head, on top of the parts already bought. So I’m tempted to break the old glaze, put in new rings because at least those won’t break, hope they seat well enough to not drink more oil than the car already was, and hope it all holds together for the next little while. The bearings are alright, it looks like they can be reused without spinning, albeit only for the above stated 10 month time frame. I’d worry about it in 2 years otherwise. This has already been a bad investment and every dollar makes it worse, all for a car that could blow up in 10 months for all we care… just not sooner. So we’re trying to cut our losses and just make this thing survive short term. Any tips on the best brands of bubble gum and duct tape to use on this thing would be appreciated.