Shining new rear main

Behold the glory of a new rear main bearing -0.020"

Many thanks again to David and his wife at Stewart Engineering.  I wouldn't have been able to get this far without them.

Now that I know the exact measurements of the bearings, the crank will go off to the machine shop.  First I'll have to find one who can do a good job.

In the meantime, I have lots to do.  I have to make new brake linings for the front shoes... and probably the back as well.

During all this my poor XS650 has thrown a crank bearing, and is torn completely apart.

Speedometer

If anyone wants to know, the bezel of the speedometer screws on and off of the casing.  I bruised my hands trying to loosen it, but it finally came off after prying at the case to try to get the threads loose.

I stripped off the odometer and trip odometer numbers so I could blast the rest clean with solvent.  Its filthy with crud on the inside, and simply wouldn't work properly.  The trip odometer went back together easily.  The main odometer will go back together tonight.  Its an interesting mechanism, not at all like a car speedometer.  It actually samples the speed and holds it until the next sampling cog comes around.

Rear main pressed out / wheel bearings cleaned

Pressing out the rear main wasn't a big deal.  The hydraulic press at Tiger Tom's made short work of it.

I took this photo to remind me the orientation of the oil holes in relation to the pump housing plate.

Its off in the mail to Stewart Engineering to be swapped out for a 20 thou under bearing.

In the mean time I began tinkering around with other things.  The seat could go back on, nothing holding that process up, so I put that on.  The odometer was really stiff turning, so I cleaned the right-angle gearbox for that.  It still turns stiffly, and I'm not happy about it.  I also couldn't figure out how to disassemble the speedometer.  I know its sticking, because I used a stub of the old speedo cable in the drill to turn it.  It stuck at 20mph.  Its going to need cleaned out.  Work for another day.

The next thing is to tear into the wheel bearings.  The rear came apart easily, and the grease looked good in there.  There was no ingress of dirt, so I cleaned it up and re-packed it.

The front wheel bearing on the otherhand did NOT want to budge.  It took three days soaking in PBlaster before it would even move.  I kept striking it with a tool I had made to back it out.  The left-handed thread was a bit awkward, but finally it started to move.  I was glad the rear moved easily, because I didn't realize it was left-handed.  I was surprised that once it started moving it came out rather easily.  I found those bearings to be in good shape as well.  Cleaned the old grease out and put new grease in.

I proceeded to clean the wheels.  The front is in nice shape.  The paint is good and there is very little rust.  The rear on the other hand looks like it was used excessively for braking, because the paint looked overheated and there isn't much left.  What to do, what to do...  I hate to paint it, but its just bear rusted metal on the brake drum.

I drained some of the old gas out of the tank into the lawnmower.  It burned just fine.  Next will be to clean out the gas tank really well.  The one petcock (newer one) leaks a little, the original one, doesn't leak at all.

Dizzy Reconditioning

The distributor needed tearing down to put the new oil seal in, so I figured it was a good time to just recondition the whole unit.  The pin holding the dog to the distributor shaft turned out to be a broken off tap.  It seems to be nice and tight, so it shouldn't be a problem.  The points seem to be in good shape as well.  The problem came when I noticed that the advance plate wasn't securely fastened to the shaft.  This could cause all kinds of inconsistent firing, so that had to be fixed.  It seemed to be simply pressed together without much mechanical resilence left in it.  The easiest thing to do was to get out the mig welder and put a few tack welds to hold it in place.  I seemed to get a good weld, and ground it all down nicely.  With that repaired, I noticed that the springs on the centrifugal weights were mismatched.  I checked the resistance of the springs and found them to be pretty much the same.  That was good, but the one spring was longer than the other.  That wasn't good.  There was enough slack to allow one spring to be floppy when the other was tight.  I bent the longer one so it was roughly the same length as the other one.  I suppose that will do for now.  Its not hard to tear it apart again if it gives me trouble later on.

I foolishly didn't notice that there was a center punch mark on the point cam, when I took it apart.  I couldn't find a diagram of the distributor on how it was supposed to be assembled.  I assumed that the center punch mark goes on the same side as the center punch mark on the end of the shaft (toward the engine).  That makes sense, but if it turns out I'm wrong, its an easy fix.

I repacked the top bearing, and put the new oil seal in.  The old oil seal was like all the other ones on the bike, completely petrified.  I noticed that there were some makeshift shim washers in the assembly, so I put them back in the way they came out, with a bit of grease on them.  It USED TO work, so it should work again.  It turns freely and the points are nearly the same opening on both cam lobes.  I set the gap and put it all back together.

Well, almost back together.  The one insulating top hat washer on the point spring was damaged.  I'll either repair it with some epoxy or find a suitable replacement.  All the TO-3 transistor top hat washers I had were all too small.  I'll have to poke around and see what else I can find.  Once again an easy fix later.

Top End Teardown

I decided to use the day off to take the head apart.  The parts washer came in handy again.  I stripped all the rockers, spacers, and springs from the rocker shaft.  Everything looks good.

It doesn't look like any of the chunks of pulverized rear main bearing got up into the head.  That's a relief.  I was hoping for no problems on the head.  I cleaned out the oil passageways really well... using a pipecleaner brush.

I'm trying to clean as much crud out of the fins as I can.  I don't want to glass-bead any of the parts to maintain some originality.  I just don't want all the dirt on the fins... patina in one thing... dirt is another.

Cleaning, Preparation, and Bearing Gaps

There isn't much to tell about my progress. I received another order of parts from Stewart Eng. I've cleaned the engine block and checked the new rings for clearance after honing. Everything checks out there.

The next step is the big one. I need to find a reliable machinist to turn down the journals on my crankshaft. I'll also be ordering a set of big end shells and a new rear bearing. I need to get a good idea of what undersize bearings to order.

Below is the measurements of the crank that I've taken.  It looks to be a 30 thou under on the big ends, and a 20 thou under on the rear main.

Anyone know, what measurements I should tell the machine shop?

I would think:

-0.030" bearing shells... grind the big ends area "A" to 1.5950" / 1.5945"

-0.020" rear main grind the rear shaft area "C" to 1.4795" / 1.4790"

But would it be more wise to hand the machine shop the rods, and bearing shells .. and ask for a gap.  What gap?  Would that be 1.0 thou or 1.5 thou gap?

Opinions?

Eduardo joins the family

In 2005 it became quite clear that my wife wasn't going to let me drive the Red Imp very often, and if I wanted to drive an Imp, I would have to obtain one of my own.  After passing up a few on eBay and going to see a Mk3 in Maryland, I finally found the ONE.

September this car came up for auction on eBay.  It seemed well cared for, and had a bit of history to it.  The body was the best I had ever seen on an Imp (which wasn't much).  It was a California car and hadn't been sujected to the snow and salt of the north east.



Val and Tiger Tom went to pick him up while I went on my annual motorcycle trip to Elk County with the Friends of Nature.  We discovered some important aspects quickly.  No brakes, No Oil Pressure, No compression on number 4 cylinder.  Just the kind of work I can do... the body was fine, all it needed was a bit of wrenching.  There wasn't a spot of rust on the undercarriage and the only issue was a leaky steering rack boot.

The wrenching took four months.  Looks tiring doesn't it?



In the meantime, we learned some of the history of the car.  The original owner Eduardo Pallazo from California must have loved this little car.  He painstakingly maintained it, kept his reciepts from Sunbeam Specialties, and created a one of a kind wooden dashboard for it.  Legend has it Mr. Pallazo was a Hollywood carpenter and set builder.  The dash was fitted to take the place of the Mk2 cardboard shelf in the standard car.  We refer to the car as "Eduardo" now in honor of the car's first owner who cared so much about it.  Originally taitian blue, the car had been resprayed Toyota Super White II, which makes it a bit stark like a rolling refrigerator, but the interior makes up for it.  The stock Imp seats had been replaced with VW bug seats, with the bottoms cut off.  The rest of the interior which would have been orginally vinyl was decked out in a blue velour.  Oh, Eduardo is a pimpin' little Imp.

Sorting the brakes was no big deal.  The master and slave cylinders were stripped and redone, and refilled with DOT 5.

The oil pressure problem was the big deal.  The mains were shot and so were the big ends.  The engine bearly made oil pressure at idle.  Someone screwed up majorly, and had installed an external oil filter in a way that basically short-circuited the lubrication system.  It was basically a new block for goodness sake, and it was almost ruined!  We took the claptrap off, and concentrated on new bearing shells from Speedy Spares.  Luckily it wasn't too bad and we didn't have to turn the crank.

Number 4 piston had us going for a while.  It wouldn't develop compression, and would simply leak by the exhaust valve.  We pulled the tappet shims and measured them all.  Oddly enough the number 4 intake and exhaust tappet shims had been reversed by the previous klutz to put the engine together.  They were swapped, and the engine ran like a champ!

I took a few victory laps outside Tiger Tom's workshop in 4 inches of fresh snow, drifting the Imp happily around the snow covered blacktop.



Later I pulled out the Subaru radio and put in an MP3 CD player out of a Ford truck.  I can now play all my bagpipe music on MP3s.  The dash was refinished and restored to its original glory.

I later replaced the transaxle mounts... with the engine still in.  It CAN be done, but I don't recommend it.  The front of the gearbox would fly up and hit the bottom of the tunnel... so new transaxle mount were a MUST, and of course supplied by Uncle Malcolm Anderson.

The work wasn't over though.  The Solex (err Slow-lex) carb kept acting up.  I couldn't tune it right, I even got a rebuild kit of Uncle Malcolm and it still wouldn't tune up for me.  I finally gave up and in an impulse ebay purchase got a set of SU HS2 carbs and a LYNX manifold from a fellow in Oz.  Now I was commited to getting the engine to run right.

The Lynx manfold came with two carbs alright... two left-handed ones.  Blast!  How I had to get creative.  The linkages didn't work out, and I had to create custom ones.  I think I'm the only person running two left-handed carbs on a Imp in the whole world.  I tilted them, cutting a groove in the bowl to housing junction to get them to stay level.  Then I changed the routing of the throttle up over the top, to meet with a custom bracket I had made.  Notice the big spring tower to hold the throttle closed (the spring came off an upright Hoover vacuum cleaner bag).  It all worked out rather well.  I even used an old clutch cable to join the enricher levers to the existing choke cable.  The whole thing was topped off with a K&N air filter from a Suzuki GS750 motorbike.

I ended up with the V3 needles and blue springs per http://www.imps4ever.info/tech/carbs.html#SUs



I thought I was done, but there was something else not right.  Every time I made a left turn.  Especially one made in anger, the oil warning light would flash.  Now friggin' what?  It shouldn't do that.

So, I pulled the sump cover off again.  Nothing looked strange, but having limited experience, I had no idea what could look out of place in there.  So I consulted the great gurus of the Imp club, and they informed me that my oil pickup was off a 930cc engine.  Well that makes sense... it was made for an engine that sits straight up rather than at a 45 degree angle.



There were no replacements of the right type readily available, so I went on modifying what I had.  I got some idea of how close it should be from the bottom of the sump and did some basic cutting and re-welding.

I think it turned out pretty good.



Now I can turn left in anger.  In extreme anger at the autocross last autumn it performed flawlessly.

Eduardo had been very reliable, comfortable on a long trip, and a joy to drive.