Bush Mechanic

Thanks for the reply, scotchyoke.. The problem was not resolved, actually. I left on extended holidays, and the owner placed the Orient back in the museum. My notes reveal that I did move the valve timing one tooth, which brought it right on the average timing for similar engines of the period, but didn't get a chance to follow up with any more testing. I agree that the engine needs a proper going through. It is now on the back burner, I guess.

Ah, now were getting to the heart of the engine! I've been looking forward to this part of the build. That's an odd looking camshaft set-up. It looks as though they were relying to some degree on valve spring pressure to keep the shaft located in it's centre bearing. Are there any machined faces under there that would accept a bearing cap? Hopefully you have access to a proper line boring machine. Or perhaps you have previous experience in this field. I attempted my first home-made boring bar job recently, and it was a little tricky to get it right. I certainly cannot offer guidance, as I am a complete novice in this field. But if I may mention two unexpected pitfalls which I did not anticipate when thinking it through. One was the shape of the single HSS cutting tool. Too much rake in the grind, and the cutter will dig into the alloy bearing surface. The small amount of flex in the 36 mm bar, combined with the necessary clearance in the home made bushings supporting it, allowed the cutter to dig in if you went too hard or attempted more than .003"-.005' each cut. Just barely enough back-rake to give clearance seemed to work best. The other problem was that I needed more clearance for the scurf to flow out of the bearing. And more scurf clearance on the boring bar increases the possibility of flex. So it was a slow job. I tapped a stud into the end of the bar in order to drive it with a cordless drill, and then controlled the feed with my other hand against the other end of the bar. I final-finished with a brake cylinder hone on an extension bar. Primitive and agricultural, no doubt, but the camshaft now has a nice feel, with close to my target clearance of .003" in each of the four bearings. Hopefully it will hold up OK. Good luck with yours, JV. It seems to have a lot of camshaft spanning between bearings. Is the shaft only one inch, or is that just the size of the test set-up?

My Mum was proud of the fact that she could beat the bus into town, driving her one-horse gig. It was seven miles, and admittedly the bus had to stop occasionally. She never drove a car. Thirty miles was a big day's run for both harness and saddle horses, but longer trips were probably not uncommon.

Very nice. Thanks for posting the photo. The overhead gear and layout bear a remarkable resemblance to the post-war Austin engines.

Bloo, I some-how recalled that the OP had posted previously on another question, and revealed the make and model concerned. Perhaps not mentioned in this topic. The rather unusual vehicle, (for this site), caught my attention.

I see the OP's problem. Big end inserts, pistons, rings, rods, no problem. But main bearing inserts for his E493A Ford Prefect do not seem to be available. At least from those small-Ford suppliers in the UK which I looked at.

Whoops, posted that in the wrong place. Working off a phone. You will know where it belongs, at least.

Phillip, new main bearings for the 1172cc Prefect engine are available online for around €23 plus freight. Available in std., .010", and .020" under-size at least. If the crank is definitely re-ground, I suggest having it checked and measured, if size stampings are not obvious, and treating it to a new set of shells. To answer your question, it is not usual or normally advisable to fit used shells on a reground crank. However, if a supply of used shells of the same under-size is at hand, careful checking and measuring with plasti-guage may just turn up a usable set within clearance specs. If they are not within spec. right across the journal, they would not last, and may damage the crank.

Electrics are not my strong point either, but it reads as though a short circuit is draining the batteries fairly rapidly. Is there a sparking at the battery terminals when connecting them? ( All switches turned off). If yes, you could pull the fuses , connect volt meter across the battery, and insert the fuses one at a time, looking for voltage drop. That would give an indication of where to start looking.

That exposed crank machine looks interesting. The SMOKESTAK, (no C), forum is a good starting point for info on these engines. There are many active clubs in Australia, with up to a dozen engines running at one time at the agricultural fairs. I attended an Australia wide get-together here in Tasmania, and realised that much of the machinery that I use daily is 'collectable'!

We call it a speed brace in Australia. Use it most days.

And it has 'patina'.

Eric Gange's Garage, near where I grew up, had this problem sorted. Remove tank, drain petrol, face tank across the yard toward the paling fence, and insert lighted oxy torch in the filler neck. When it bounced off the fence, it was safe to weld on. Eric was a bit rough around the edges, but he could fix most things. Personally, I'm a little more circumspect, and leave the garden hose running in the tank for a while, THEN use Eric's test. Haven't had one take off yet, but I do hold my breath.

Hi, Mike. From this distance it appears that the area you suggested lightening is actually the counterweight. The arrow may be deceiving me, though. I would leave the weight as it is. The little engine might appreciate some flywheel, when it meets a hill.

Hey, Mike, you are going great. I do enjoy your posts. I think the bolt idea is sound, if you can find clearance, and enough meat left in the job, but they would need to be virtually a press fit in the holes if you are going down that road. Properly riveted, they would swell right through to create a very tight job. And as Joe said, do them one at a time before you remove the originals. Remove one, replace, then move on to the next. It will then retain the original balance. Hot riveting pulls the two halves together nicely, but when it cools the shaft fit goes away. That looks like a cold rivet job, to me, starting off with a very snug rivet fit. And to set the record straight, yes, going like a shower of sh.. does mean it's going like a cut snake. And if the poo hits the fan, it's definitely all gone pear shaped. Pretty logical, I reckon.