|The MGA With An Attitude
DORMANT ENGINE TECH -- DE-102
A little longer stretch towards salvaging a SEIZED ENGINE (on a budget?).
At 08:39 AM 1/22/99 -0800, Michael P. Thelen wrote:
>.... That thing is so seized I don't know if I'll ever get it going!
Where there's a will, there's a way.
>.... I ended up tearing the head off the block. .... My gasket is sort of metallic and it did not look "blown" or "torn" as I thought it would.
The laminated copper head gaskets usually don't "blow", but they are actually more prone to leakage than the fiber head gaskets. Exhaust gasses blowing past the gasket will usually discolor the iron surfaces, while coolant may or may not leave any marks. Antifreeze and water mix is not too hard on a parked engine, sometimes actually acts like a lubricant and anti-seize if it's near a 50/50 mix, although you can still get some rust. Plain water on the other hand is horrible in a parked engine, rusts up the cylinder walls and piston rings, steel valve stems and iron valve guides, generally bad news as you seem to have discovered.
>The cylinders are full of rust .... I put penetrating grease, and transmission fluid on them
Considering that it's rust, better to try penetrating oil, Liquid Wrench, or PB Blaster. If that fails, try phosphoric acid which can actually eat the rust.
>trying to roll the car down the driveway and pop the clutch - only to skid for a couple feet.
At least the clutch works, and apparently the shifter.
>Two of the valves are also rusted in place. Hitting them with a block of wood and a hammer only nudged them into another place, they did not come back to their closed position when the head was off.
You can probably get this to work with a ball pein hammer (whee). But first consider disassembling the valve springs. Best to remove all the valve springs first, much easier to move and inspect the valves that way, and it sounds like you need to disassemble it for inspection anyway. I highly recommend buying a good valve spring compressor tool (about $25), looks like a large c-clamp with a vise-grip style actuator. If you're on a really tight budget you can do it without this tool. Remove the rocker shaft assembly, put the rocker mounting studs back in the head, use a flat washer and hex nut at the top to hold the end of a box end wrench, and use that to lever down the valve retaining caps. A couple of extra hands are very useful for this job. Also expect the cotters (split retainer clips) to be stuck. You will need to have something under the valve head to hold it up while you are prying down on the cap at the top, then give the cap a sharp rap with a hammer to break the cotters loose.
To open the valve, tap directly on the end of the valve stem. To close the valve, tap straight and directly in the center of the valve head. Do not hit the valve head on the edge or off center, as you could bend the valve. Apply penetrating oil in the guide to stem junction and keep tapping it back and forth until it loosens up. When it gets loose enough you can put an electric drill on the end of the stem and spin it a bit to get it really loose. For proper operation the valve should fall in/out of the guide by gravity alone. The good news here is that if the guides are that tight, they're probably not worn out too bad and may be serviceable when you're done.
If perchance the valve stems are still too tight in the guides, you can take an old valve (free for the asking), cut the head off, chuck the stem in an electric drill, apply a little lapping compound, and use that to hone out the guides until you get nice loose operation of the valves.
When seated, the valve heads should protrude a little above the surrounding surface of the combustion chamber. When a little worn, anything down to being about flush would still be acceptable. If the top of valve head sits below the surface of the chamber, something needs to be replaced, either the valve or the seat (or maybe both). You can drop in the new valves, but replacing the seats is a machine shop job.
If the guides are indeed in good condition (less than 0.005" wiggle), then you can try lapping the valves to the seats to shine up the interface and get a good seal. Personally I figure that's way too much work. I prefer using a valve refacer tool. J.C. Whitney sells one of these for under $10, and it really works (surprise). It's a little hand held jig that fixtures a small grinding wheel at 45 degrees to the valve head. You oil up the stem and spin the valve with an electric drill, and the head of the valve runs against the side of the free-wheeling grind stone until the valve looks like new again. If the valve head gets too thin at the edge it will need to be replaced, otherwise it can be reused.
Next step is to apply a couple small pieces of self-stick sandpaper (supplied with the tool) to the newly ground edge of the valve (clean with solvent first). Then you drop the valve into the head and spin it a little with the electric drill to clean up the mating valve seat surface. Nice trick, this Grapes of Wrath valve job, and it actually works (as long as the guides aren't too sloppy). When finished, clean everything up with lots of your favorite cleaning fluid (gasoline is cheap), and reassembly is the reverse of disassembly. And while you're at it, I suggest that you install Felpro Umbrella seals to cut the oil consumption and smoking on start up.
While it's this far disassembled, you might a well pull the rocker shaft assembly apart for inspection. As a quick check, push one of the rockers over along the shaft against the spring to expose the running surface of the shaft. You might expect to find wear on the bottom of the shaft where the rocker normally runs (step in the shaft that you can feel with your finger). Fairly often the shaft wears a lot and the bushings wear very little (long explanation). If you push the rocker aside and the wiggle goes away, then you could use a new rocker shaft ($21) but not have to touch the bushings.
>The night ended with a few more squirts of transmission fluid to the cylinders to just let it sit like you suggested.
Try PB Blaster. In theory it should work better than Liquid Wrench or WD-40, but I haven't personally been able to verify this yet. Lots of good testimonials for this product though.
>The thing I am wondering now is - do I get rid of the car and start with another that needs less work and less money? ....
Oh, ye of little faith. So far you aren't out much, and the instructions above should give you a good working cylinder head. At least don't give up before you try all the cheap stuff. If you remove the starter motor you can get access to the ring gear on the flywheel. Here you can use a pry bar to get tremendous leverage at the outer edge of the flywheel to turn the crankshaft. If you still don't get it to rotate, it's time to pull the oil pan.
Considering that the cylinders are badly rusted, at the very least you will need to (at least SHOULD) remove the pistons and hone the cylinder walls. Be persistent, and you will get the pistons to move. You may end up having to remove the oil pan, in which case it may make good sense to pull the engine out of the car. With the head off you're already more than half way there to having the engine out.
So then you remove the oil pan and remove the bearing caps from the connecting rods. As a matter of convenience for access, also take the oil pump out. Do not mix up the bearing caps, they must go back on to the same mating con-rod, because they are bored in assembly, and the split line is a little off center of the bore. If you switch a couple of bearing caps, one bore ends up too small and the other ends up too large.
With the rod caps removed, try rotating the crankshaft again. In this case you only have to move two pistons upward in the cylinders, as the crank journals will just fall away from the other two rods. Turn left to move two pistons. Turn right to move the other two. If you still can't get it to budge, then the engine has to come out of the car so you can remove the crankshaft. At the front remove the front pulley, timing cover, chain tensioner, sprockets and chain, cam thrust plate, and then the engine front plate. At the back remove the clutch and flywheel, then the engine rear plate. Then remove the main bearing caps to get the crankshaft out. A slide hammer is of good assistance for pulling the main caps, but you might get creative and figure out how to do it with bolts and washers and pry pars.
Once the crank is out you can beat the pistons loose with a big wooden drift and a heavy hammer. That never fails, they will come out. Still having trouble, just get a bigger hammer. In the very worst case you may end up damaging the ring grooves, or even breaking the pistons, but they will come loose.
Once you get the pistons to move, they come out the top of the bore. However, before removing them from the cylinder, check the top of the bore for a wear ridge. You will most likely find a ridge here that you can hook your finger nail on. You should remove this ridge with a ridge reamer ($25-$30 tool or cheap rental). Failure to remove this ridge can result in damage to the ring grooves in the aluminum pistons when you try to push the rings past the ridge.
Having gotten this far, you may also consider removing the tappets and camshaft for inspection, as that's about all there is left of the engine assembly. There's a nice bit on another page here with pictures on inspecting the tappets and camshaft. And oil pump specs are in the shop manual, no scratches and maximum 0.006" clearance with a feeler gauge as I recall.
Run your finger across the journals on the crankshaft, they should all be perfectly smooth. If you can feel any imperfection there at all the crank will need to be reground. If it has already been reground before, the bearing shells should have the current size stamped on the back of the shell. This might look something like "0.020 U/S" or maybe just "020". Main bearings are likely to have a different regrind size than the rod bearings.
Crank grinding is a specialty job where the shop that does it does nothing else. Your local machine shop would likely send the crank out to the grinder and add a little markup for his own trouble. If you can find the grinding shop and deal directly you can save a little money. Regrinding should cost $75-$100 on your 4-cylinder crank.
Then the tricky bit is checking the size of the cylinder bores. As a crude check (after cleaning), wrap a piece of paper around the piston and try putting it back into the cylinder. Standard writing paper (or printer paper) is about 0.003" thick. If the piston goes into the bore with the paper wrapped around it, it's likely that it will need a rebore. Then again, it may already have been rebored and have oversize pistons.
Clean off the carbon on the top of the piston and look for any numbers stamped on the top. An oversize piston should bear some numbers like "0.020 O/S" or maybe just "020". You can measure the piston and/or cylinder bore with a dial caliper ($20 for a decent cheap tool). The best and proper tool for measuring the bore would be an inside micrometer ($$$$), but you probably don't need that much precision unless it's really bad and you're trying to determine how much it has to be bored out to clean it up.
The next best gauge of the cylinder bore would be to get a new piston ring of the appropriate size and put it into the bore about 1" down from the top, then measure the gap at the ends of the ring with a feeler gauge. With a new bore the gap should be about 0.008" to 0.014" (as I recall). Any wear (oversize) in the bore increases the gap by 3.14 times the change in diameter (pi, you know). 0.005" wear in the diameter would make the gap nearly 0.030", in which case you could probably get away with new rings and reusing the old pistons (I do this a lot). A gap larger than 1/32" indicates the need for a rebore.
If you're ready to re-ring your engine using the same pistons, you need to hone the cylinders. In your case you need to do this anyway to get rid of the rust and clean the walls. The better hone would be one with three straight stones (longer the better), as they will help to straighten the worn walls a bit ($10-$25 tool, and maybe hard to rent). Forget the ball hones, they're just for doing up a new bore or a replacement cylinder sleeve where the bore is already true and straight. Before honing a cylinder you absolutely must remove the ridge at the top. Run the hone at a moderate speed, less than 1000 rpm, keep it oiled to carry away the grinding debris, and keep it moving up and down the bore as it runs to generate a criss-cross pattern of grinding marks on the wall. You have to remove all of the shiny glazed surface and keep honing until you get a nice even buff surface appearance in the entire bore.
If your engine is badly worn it may be in need of a rebore and oversize pistons. This is a professional machine shop job, unless you have a really good milling machine that's large enough to take the engine block. The shop will bore and hone the cylinders and return it to you ready for reassembly.
If you are going to do the engine assembly (highly recommended) you will need a torque wrench. Check the manual for the highest torque required anywhere on the vehicle (maybe a wheel bearing nut) and get a torque wrench big enough to cover all the applications. Very good torque wrenches can be had for under $50, cheap ones are under $10. This is a lifetime tool, so get a good one if you can afford it.
When time for assembly, the crankshaft bearings go together with finger pressure, just be sure to keep them immaculately clean. This is where you get to feeling like a surgeon. As there is only a couple thousandths of an inch running clearance in these bearings, any little grain of sand or human hair caught in the assembly would make the bearing seize and cause damage. Install the main bearings first, dry on the back and lots of oil on the working side, set the crank into place, then tighten the caps gradually one at a time, and keep rotating the crank to assure that it always rotates freely.
Once the mains are torqued up to specs, then install the pistons and rod bearings one at a time, and be sure that those also run free. Expect a substantial amount of drag on the new piston rings in the honed cylinders. A ring expander is a handy gadget (less than $10) but not absolutely necessary. Just be sure you don't break one of the new rings while installing them, as there are never any extra parts in a ring set. Also a ring compressor is almost a must (again under $10) to get the things into the cylinder bore without damage.
>There is probably even more wrong that I don't even know what to look for.
Just take it apart and look it over. Most damage is immediately obvious and easy to spot.
>How much does it cost to clean that engine and make it run?.
If you just want to make it run, not much. Get the pistons to move, oil it all up a bit, put it back together and fire it up. Cleaning fluids and gaskets are fairly cheap.
>Whats my next step?
Get the pistons to move. If you can do that without taking it apart any farther, it's a good bet that you can just put it back together and run it. It may smoke some and burn oil, but hey, oil is cheap. How tight is your budget?
>I feel frustrated and hopeless, but at the same time challenged and a desire to make this car work. What do you think?
There ain't nothin' like reviving one of these things from the dead and making it live again to give your ego a huge boost. And it's great experience for learning to maintain your own car so you can save a bundle of money in the future. The best part is knowing exactly what you're doing after you've done it once, so in the future you can do only what is needed and not pay for anything that is not needed. That means not getting ripped off by unscrupulous repair shops for the rest of your life. Gotta be worth something.
Suppose you do all the mechanical work yourself and only farm out the required machining work on the block and head and crankshaft. In the worst case you should be able to have a totally new engine for under $1000, including hard valve seats for a no-lead head, rebore and new pistons, reground crank and new bearings, new oil pump and timing chain and tensioner, and new rocker shaft and bushings. If all you need is new rings, bearings and gaskets, the tab could be less than $200. A new cam and lifters would run the bill a little higher. Only way to know for sure is disassembly and inspection. If you're not sure, take the block and head and crank to a shop for professional inspection. For about $50 they should clean it all up and tell you exactly what it needs, maybe $20 more if you have the head and/or crank magnafluxed.
Keep working on those pistons, and let me know how you make out.