The Bucket Foundry

[WilDun]

Wil, you understand how to machine, so already know what's required for CNC, it just requires a list of instructions and co-ordinates etc.

Yeah, I just need to buy a CNC machine! (well I do already have a little engraver).
I don't regret not learning CNC way back, because I had a ball doing the stuff I liked in my own little corner of the factory (which made various kinds of valves), things like coreboxes, jigs and fixtures, prototypes etc. Much better than being a personal slave to a CNC machine!

[Flettner]

No more engine projects these last few weeks, work is getting in the way. For example, wheels for Mustang 3/4 scale replicas. Cast in LM 25, heat treated to T6 then finished machined. Five sets (ten wheels), castings done by Skellerns in Auckland. Nice casting job too, no inclusions. We made the pattern in house.

[Flettner]

Also an order for five gearboxes similar to this one. This is a 160 HP three gear unit to suit the Honda Fitt / Jazz engine.
The ones we make for replica Mustangs fit on to a Chev V8 engine of some sort, just over 300HP. We would have made at least sixty of these 300HP units now.
2.21 to one reduction ratio, V8's are 1.9 to one. Gears are all EN39B case hardened to 60R.

[Grumph]

There was a guy down here converting V12 Jag motors for replica Mustangs/Spitfires. Market seems to have dried up.

I was told many moons ago that for best life a gear pair should be dissimilar steels...One in say EN39B, it's mate in EN36A. The close ratio bike box conversions I've done have all followed this path. Comments ? Experience ?
It's worked for me but obviously not with the loads these boxes will see.

[WilDun]

No more engine projects these last few weeks, work is getting in the way. For example, wheels for Mustang 3/4 scale replicas. Cast in LM 25, heat treated to T6 then finished machined. Five sets (ten wheels), castings done by Skellerns in Auckland. Nice casting job too, no inclusions. We made the pattern in house.

Nice job, are the wheels of similar alloy to "mag" car wheels?
I hadn't realized that the little Honda engines were being used in aircraft - thought the Suzuki and Toyotas ruled.

Also are the newer Chev engines still cast iron?- must be heavy! and why do they use a 3 gear reduction box - one idler maybe ?

I think I'm getting a bit behind here!

[Flettner]

Nice job, are the wheels of similar alloy to "mag" car wheels?
I hadn't realized that the little Honda engines were being used in aircraft - thought the Suzuki and Toyotas ruled.

Also are the newer Chev engines still cast iron?- must be heavy! and why do they use a 3 gear reduction box - one idler maybe ?

I think I'm getting a bit behind here!

The engines are alloy block not cast iron. Three gears are there to shift the output shaft center to the right place for the aircraft and also to get the rotation back the same way as the crankshaft. Yes I think car "mag" wheels use CC601 or LM25, similar material.
I am happy how the wheels have turned out, seems the dollar at 65 cents ish in the USD has driven work our way, about time and long may it last. All these components are exported to the US.

[Flettner]

There was a guy down here converting V12 Jag motors for replica Mustangs/Spitfires. Market seems to have dried up.

I was told many moons ago that for best life a gear pair should be dissimilar steels...One in say EN39B, it's mate in EN36A. The close ratio bike box conversions I've done have all followed this path. Comments ? Experience ?
It's worked for me but obviously not with the loads these boxes will see.

Greg you might well be right. In a close ratio gearbox I would imagine the gears are a compromise, so there would be some tooth face sliding going on. When gears are build to the calculated sizes there is just a rolling tooth interaction so in our case we use EN39B for all three gears as it's the best for maintaining a hard surface and has the strongest tooth root. These gearbox teeth are calculated to do 4000 hours at 300 HP, bending fatigue life, with a heafly safety margin. There have been a few failures, mostly when the aircraft interfaces with the ground the wrong way We did have an early failure due to tortional frequency issue with the use of a heavy prop. All props used now must be under a certain weight. Change to a steel flywheel would help. We use a Centerflex (rubber) coupling to join the engine to the gearbox, without this coupling the gearboxes would just smash teeth off, piston engines are rough buggers.

I learned the hard way about dissimilar metals, I made camshafts for my Subaru EA82 development engine. I made new heads with double overhead camshafts (four cams) but I used EN39B for the cams and for the buckets (buckets were offset from the cam center to induce turning). Within a short time heavy cam wear was evident, went through several sets of cams (and buckets) before I worked out what was happening. Had the buckets hard chromed and laped, that fixed it but not before I had decided I hated camshafts and fourstrokes. Too much stuff to make, too expensive to make.

[Grumph]

Greg you might well be right. In a close ratio gearbox I would imagine the gears are a compromise, so there would be some tooth face sliding going on. When gears are build to the calculated sizes there is just a rolling tooth interaction so in our case we use EN39B for all three gears as it's the best for maintaining a hard surface and has the strongest tooth root.

I learned the hard way about dissimilar metals, I made camshafts for my Subaru EA82 development engine. I made new heads with double overhead camshafts (four cams) but I used EN39B for the cams and for the buckets (buckets were offset from the cam center to induce turning). Within a short time heavy cam wear was evident, went through several sets of cams (and buckets) before I worked out what was happening. Had the buckets hard chromed and laped, that fixed it but not before I had decided I hated camshafts and fourstrokes. Too much stuff to make, too expensive to make.

The sets I've done - well, rough turned myself before farming out the cutting, splining, finish grinding etc - have been on the same module as the ones they've replaced. Where it's a sleeve gear 'box keeping the same total no of teeth on the output pair but going up one on one side and down one on the other can close all the ratios up appreciably - and simply too.

Several years back i was in kelford's to see about some cams, got asked about a set of billet Z1 speedway TQ cams they were having trouble with. Like your example, hardened steel billet cams running on hardened steel buckets. OE was of course cast iron cams...
At the time they couldn't do much except nitride the cams which gave acceptable life. Now there are an enormous number of cast iron cam blanks available - ex Turkey of all places. Next time you want to play with cams for a mass production car engine, there's probably a CI blank available.

[seattle smitty]

I learned the hard way about dissimilar metals, I made camshafts for my Subaru EA82 development engine. I made new heads with double overhead camshafts (four cams) but I used EN39B for the cams and for the buckets (buckets were offset from the cam center to induce turning). Within a short time heavy cam wear was evident, went through several sets of cams (and buckets) before I worked out what was happening. Had the buckets hard chromed and laped, that fixed it but not before I had decided I hated camshafts and fourstrokes. Too much stuff to make, too expensive to make.

Don't feel too bad on that one; General Motors managed to do the same thing with what otherwise was an innovative motor for it's day, the Pontiac OHC six of 1965 or thereabouts. Incompatibility between cam and lifters meant that a lot of engines that maybe hadn't been carefully broken-in wore out prematurely. Other than that issue, a pretty neat six, if a bit heavy.

http://www.overheadcammerschapter.150m.com/history.html

[Flettner]

The throttleable transfer FOS cylinder (sliding cylinder) mated up to one of the ISO standard donkey cases, slow progress.
Still need to make a head that attaches to the top of the water jacket and goes down inside the cylinder. Sealed with an oring and a piston ring in front of it. Head will be water cooled also. The three exhausts will be interesting, not sure if I should have a three into one or just three pipes?

[Flettner]

Just standard case reed, will try 24/7 system with this setup later on.

[adegnes]

Very nice!
My vote is for three exhausts, just because it would look ridiculous! Probably easier to get right too, if that's a pro or con is up to you...

[F5 Dave]

Operating same bore, but I'd go 3 as at least you know the resultant isn't being held back by the pipe.

[Flettner]

Very nice!
My vote is for three exhausts, just because it would look ridiculous! Probably easier to get right too, if that's a pro or con is up to you...

I guess? Still a wee way from that yet. These are the same cases as used with the sleeve engine. I'm looking into makeing some pipes for that engine via hydro forming. I see on another thread some real nice results.
Still on the lookout for YZ250 twostroke gearboxes (or engines) 02 onwards, for these cases. Probably end up getting a whole bike and wreaking it, must be parts others want?

[F5 Dave]

SSS forks are pretty good but 06 onwards. Just put some on my GasGas. Actually we've talked about that. After the engine and pipe only the wheels would have a market, and not a large one. Doubt you would sell much else.