Once again, I noted the awful knocking noise that I hate... and this time resolved to do something about it. I know what causes it, the wrist pin journal is oversized compared to the wrist pin by about 2mm! Simple enough to fix...
I need to press the old bronze journal out of the conrod, get someone to machine a new one which fits the existing wrist pin and press it into place. It also needs an oil hole and a lubrication groove cut into the inside of the journal. I had to replace my old conrod because it's big end was very bad. The little end of the "new" one is oversize by at least 2mm compared to the wrist pin. I kept it this way to get the engine running, but now I really need to do something about it or I'm going to destroy it. Once again thanks to Ron Haskell for coming to my aid last year in the USA to get my engine running for the Tulare (California Antique Engine Show) show when he provided the replacement conrod. Ron is a member of Western Antique Power Associations - WAPA. WAPA is my favourite Southern California club - great events and VERY active. They have shows just about every week!
Can anyone in Melbourne take this on for me? I just don't have the machinary or skills for this job.
One of the SEL members recommended I rip off the head and see if there was any crap inside the water jacket within the head. There was not, but I did find plenty of other stuff which I've detailed in this page. If you can help with any of the jobs here let me know!
The more I take this engine apart the more crap I find... The previous owner has busted the bracket which holds the valve rocker assemblies. So now I need someone who can weld cast iron. I know I did not break it because there is paint in the break! It had been glued with paint by the looks of things. It is not that drastic, I cat get a washer over the remaing casting to hold it down, but I'd much rather it was fixed... there might be enough metal to drill and tap a couple of holes and bolt it back together - I'll think about that one.
The head is ok, a bit dirty but ok. It has two freeze cracks which I did not notice before. They've been repaired by someone who is/was good at it. They are opened up slightly near the gasket face but I don't think it is any big deal - no combustion pressure gets to that area (or at least it should not!).
Interestingly I'm curious if it is actually the head from this engine. It has more and bigger holes for water inlet than the block does. The block has four small round holes (which were mostly blocked by silicone) and the head has the same four small ones plus some really big ones. I'm guessing the vynil gasket covered in silicone crap was put on by the previous owner. Some nice asbestos gasket coming up.
The cylinder is pitted to a depth of about 1.5mm in quite a few places towards the head end and in the bottom. The rings on the Ottawa are about 6mm wide and show no signs of damage and there is no scoring near the pits, so I think I'll just leave it alone apart from giving it a hone. The only alternative would be to bore and sleeve it - I just don't think it is worth the trouble. I will remove the head every couple of years and make sure it is not getting worse.
The piston was coked up (of course) and rusty on the top - with all that oil in there? huh? But the rings are perfect and the piston is more than serviceable. I cleaned it up with a brass brush wiped it down with oil and just shoved it back in the cylinder by hand. I love big engines with big rings - no ring compressor or tricks, just hold them with your fingers and push :). The only fun bit with the cylinder came to notice when I pulled it back to get the wrist pin out, there was nothing (apart from the cylinder walls) securing the wrist pin - the set screw had backed out a little and was holding nothing! I think Ottawa must be used to this problem as the wrist pin ends are camphored (sp?) in a nice curved shape so they don't score the walls. At least I know the oiler is doing its job (perhaps too well) as there was plenty of oil all over the piston - no danger of siezing this one.
The valves are really bad. The exhaust valve head is chipped and looks like it MUST leak - it obviously does not leak much because she has good compression - although it does leak if you push the piston in slowly, but I think that is more likely to be past the rings than past the valve. The inlet valve is in better condition around the top, but the stem was wasted away. I'm going to have to replace both. Anyone know where I can get a good set of Ottawa valves, or alternately any old valve which is 44mm diameter at the top, 31mm diameter at the end of the taper (and it looks like 120degrees at a guess). The shaft is 9.2mm and the overall length is 118mm with the hole for the keeper spring 4mm from the end of the stem. I could probably re-use both of these valves since the engine won't be doing any work, but why risk killing it just for a couple of valves... I would hate to think what would happen if that inlet valve stem actually broke.
I really need to look after this engine. In the USA they are not exactly rare, in fact I've seen about 25 of them which means there are probably hundreds hidden away. Here in Australia, I reckon I've probably got the only one (eat your heart out Ed... but then again you've got about 200 engines I'll never have :).
It runs quite nicely now. I've resolved all the timing problems with some minor modifications (ironically bringing the engine closer to it was originally than when I got it). It stops twice when running - it will run for about 15 minutes then stop after it has warmed up. It will start again immediately and keep going until it uses all of its fuel. It takes about an hour to burn half a litre (about a pint - I think?). I will fix the wrist pin/journal before I run it for a long period again as I don't want to wreck either, or worse yet damage the conrod.
The valves can be reasonably safely used again for a couple of years, so that work is not urgent. The exhaust valve will fail first, but is not going to be catestrophic - it will just chip bits off the face until it leaks badly enough to stop the engine. Since the piston in the Ottawa stops about an inch and a half from the head there is no danger of fouling the piston with valve bits. The inlet valve (despite its wasted stem) would probably never fail, but it did, it would likely take out the piston as the valve will not fit between the head and the piston at TDC if it breaks off the stem.
Some other work that I will look at doing are straightening the flywheel (it is visibly wobbly - probably at least 1/2") and the crank on the non-flywheel side is slightly bent - this really is not a problem as it is dead straight through the journals - it just annoys me to see it wobbling :). I suspect most of the reputation of being bouncy on the Ottawa is due to the flywheel - every single one that I've seen has had bent flywheels - I doubt they shipped that way. The engine has a tendancy to fall onto its flywheel when on skids as wide as the engine base which may have caused the problems with mine. I'm going to make some outrigger supports for the skids on mine (or maybe get it onto wheels - I have enough to make a cart for it).
I have to say I wont be using white lithium grease any more though... the new journal oil grooves in the new conrod are so good they act as a pump and suck all the grease out of the grease cup and throw it everywhere. I'm going to put something a little heavier in so it goes in under screw pressure like it is supposed to!
I want to try and get everything complete for Lake Goldsmith in November as it will be likely the last time I exhibit at that show. Moving to Emerald opens up a whole bunch of shows over that side of Melbourne - so many that the drive to Lake Goldsmith with a loaded trailer will seem less worth doing :).