I would put the engine right back in the car. You will not have a problem with valve seat recession on your classic Mini, if it isn't your daily driver, you won't be putting many miles on it. Also, valve seat recession due to unleaded fuel turned out to be not as big a problem as was predicted when unleaded fuel was introduced. You can always do the unleaded valve seats at a later time, when you have the money and if you think you must.
Only thing is.....I have a 3:1 diff I'd like to put in, and a center oil pickup, and a new clutch, and a couple of oil seals leaking, a new water pump and thermostat - if I'm gonna do all that...….
I've decided not to pull the head, rather I'm going to change the water pump and clutch, I can change the diff without splitting off the engine from the trans and I'll do the shaft seals and oil change then too, give it a good tune up, clean and paint the block and put it back in.
Today I pulled the engine out of the test stand and stripped it down, then gave it the first layer of cleaning prior to painting the block and head in the innocent OEM black - no MOWOG green on these engines, although this one is currently that color. I think that was done when the car went to England. Although there are traces of both red and a completely different green on it too. I'm going with POR black.
Hmmm.....I may be changing my mind on tearing down the engine.....even tho it has good compression and oil pressure, I didn't run it long enough to simulate a highway run, the oil pressure could fade on a long run. My thinking is this, first of all - it does have the correct block, based on the block number, thick flange and some of the stuff I found inside - more on that in a sec. Obviously the head has been off as it's been thoroughly ported and worked on. This sucker leaks oil from everywhere it can, which makes me think the block, seals and internals are original - if so they have 75K miles on them. And while that's not the kiss of death on a Mini engine like 100K is, it certainly is a lot of miles and wear. It has the correct duplex timing chain, which is showing some wear, and the clutch was pretty much worn out, as well as being oil soaked. So, maybe just a quick cylinder hone, new bearings and oil pump, new timing chain and of course all the gaskets and seals. While I have it separated from the trans put in the center oil pickup, change the final drive and replace the synchros as I'll bet #2 is weak. There isn't even a hint of corrosion in the water jackets - I've never seen one this clean before - makes me wonder what kind of antifreeze they were running in it - cause we know it has sat for a very long time and that stuff deteriorates over time and turns acidic. OTOH, maybe it has good compression and oil pressure because it's already been done, and boiling the block out for the overhaul is why it's so clean inside. I'm thinking the next step is to pull the head and see what pistons it has, if they're oversize then we know it's been rebuilt and it's probably fine as it is. Of course, we still don't know anything about the transmission. But......if the engine was rebuilt, why is it leaking oil so badly and for so long? More as it happens...…
One interesting thing, when I turned the engine over to see the internals, I found nylocks on the rod bolts! I thought some bodger had done those, but it turns out they were factory after all! I won't reuse them, and in fact the factory recommended not to use them on any engine used in a race car or driven hard.
Latest Uh-Oh.....looks like the crank has a crack in it, taking it to a crankshaft place tomorrow to see what's up.....
Crankshaft woes...… The crank expert said it was fixable....sort of. The place that was bad was under where the primary gear rides, so the plan was to machine that down to a good finish, then get a new primary gear (which has a removable full floating bushing instead of the pressed in, reamed to size one) and then have a new bushing made that would be correct to the new inside diameter. Then, given the wear patterns on the bearings, we figured the journals were probably tapered - which happens in shops that don't maintain their equipment - which meant machining all the journals too. The rods were 10 under and the mains were already 20 under......but with all that done we would have a proper working crankshaft. Or...…..we could take the new crankshaft I have and simply machine the rod bearings down from 1.75 to 1.625 and run new standard sized bearings and a normal unmodified primary gear. The tipping point was the surface the flywheel mounts to was fretted badly, and while I could clean it up, it was showing some wear, and the new crank was..... well...…..new! So we decided to go the new crank way, it should be done in 10 days or so. That will give me time to order bearings, primary gear and other bits from England. Given the other things I've found I know I'll also be getting a new cam and lifters, new oil pump, and we're discussing a lightened flywheel. Once I know how the block is going to turn out then I'll know if I need new pistons too or just some new rings...... I should hear from the block guy in a few days. In the meantime I'll be cleaning up the other bits and tearing into the transmichigan….debating on changing the final drive to 3:1 from the 3:44 it has now..... and of course I'll need to change all the seals and gaskets and clean everything out thoroughly.....so plenty to do yet in the shop. Also, here's what happens when you don't run ZDDP in pretty much any engine made before 1990, and all classic Minis....these lifters tell the tale. And this cam bearing.....
I've seen this crap on a lot of English builds....at least I'm assuming it's an English build. Buzz had a supposedly fresh engine, but when I pulled the head to put in hardened seats so I could run unleaded gas, I found the same poor workmanship - and I had to do even more to fix that one. I've almost come to expect it. But, once it's done it will be right, and good for many, many years and miles.
While the block, head and crank are out to be machined, I decided to go ahead and tear down the transmission too. The gears look fine (which is a good thing as they're nearly impossible to find now) but the synchros are tired so it will get new ones. I found the diff is a 16-62 which works out to a very low 3.825:1 ratio, I'll change that for the 3:1 I have in stock to make it more highway friendly - I've not seen a big block motor with that low a diff - 65 mph is 4500rpm! With the 3:1 that will drop down to a more comfortable 3500. The diff will also get new bushings for the output shafts, spyder gears and diff carrier and a new main pin for the spyder gears too. I also found a secret seal under the bolts that hold the hardy-spicer drive flanges on. When I removed the aftermarket central oil pickup (the pipe running across the gearbox in the pic) I found a large hole worn in the screen, good thing I decided to check it all out as part of the clean up process. I'll replace that and the oil pump too as I found the oil pressure release valve plunger stuck in the bore. There was a pretty good layer of goop in the bottom of the gearbox case too....I spent hours last night cleaning old gasket material off the various surfaces, I don't know what they used to glue them on with but it was the toughest stuff I've ever had to scrape off - it took me about 6 hours of cleaning, just on the gearbox!
Not much to report today.....just spending hours and hours disassembling, cleaning, scraping old gaskets off, more cleaning, priming, painting parts......lots and lots of parts! I hope to hear something soon from the various machine shops I took stuff to....the crank and head are no problem, but I would like to know whether we're going to have to bore the block so I can get new pistons on the way. Also need the crank guy to let me know whether I can run standard main bearings or if i'll need undersized.....
More crankshaft woes..... The "new" crank I got was cracked. The crank guy said it had been machined 10 under on the mains, and when they did that they took out the radius - he says they'll break everytime if you do that. Dumbasses..... So, back to the original...… He'll grind the end down, then I'll have to get a bushing made to fit it, and pressed into the new primary gear. Monday I'll take the flywheel up to him to make sure we don't have any issues there before he grinds anything. More as it happens.....
Wow sorry to hear about that new crank. Just because someone has the machine to grind the crank doesn't mean one has the knowledge to do it right. Some nice stress risers machined in to that crank. Good on your guy for catching the others fark up. You'll get it done & once done you'll be glad you didn't skip anything. Keep on truckin Minidave.
@Minidave They made these for so long, do many places still make parts for them? Also is there any New Old Stock out there? For my old Indian there is still 3 places that make parts. It's getting hard now but you use to could find NOS for them too.
Houston, we no longer have a problem! I had a spare engine lying under the workbench, so I tore it down this afternoon - amazingly, it has the correct Cooper S crank that I need and it's in excellent condition! I'll take it up to the machinists to have it checked out thoroughly, but I think it's the one to use. I'm thinking I'll take the flywheel and pistons et all up there and have him check the balance too. Other good news, the block is in good shape, a light hone and new rings will do it!