The Bucket Foundry

[Flettner]

If it was copper plated first, then it might take the hard chrome, but then you could try a hard chromed brass bushing, Model aircraft cylinders used to be made with hard chromed brass liners.
How about just a bronze bush with labryrinth sealing? - after all there won't be much side force to worry about.

I looked into all that, copper plate first is just show chrome, no use. Hard chrome must go straight on to the alloy using hydrfluric as an etch. Not nice stuff. Too difficult to use a brass sleeve (on the rod).

If I could get hard chrome on the 7075 rod and run it against a carbon lined bush that would have to be the most frictionless system there is?

Frits, you take the piss, this is New Zealand, no hard chroming onto aluminium, here

I've been thinking about the HCCI engine again, one suggestion (on another forum) is to use an exhaust gate (valve) to throttle the exhaust not the inlet, leaving the inlet open still. Put the carb back on and just move the needle up and down (no throttle piston) ??? See what happens I guess.

[eldog]

If it was copper plated first, then it might take the hard chrome

Nickel plate? Otahuhu Hard Chrome?
Hardchromers are becoming rarer and rarer, too much from China

Good old Alli-Bronze?
I suppose it's too fast and high a load for those self oiling/Sintered parts

thinking out side the square? I could be completely wrong

[Frits Overmars]

If it was copper plated first, then it might take the hard chrome, but then you could try a hard chromed brass bushing, Model aircraft cylinders used to be made with hard chromed brass liners.
How about just a bronze bush with labryrinth sealing? - after all there won't be much side force to worry about.

The hard chromed brass liners were succeeded by hard chromed alu liners and then the MB40 came along with linerless chromed bores (guilty, your Honor).
Labyrinth sealing may work but stationary piston rings around the rod have proven to work too.

Nickel plate? Otahuhu Hard Chrome?

Nickel is too soft. That's why they throw in sand and call it nikasil.

Is it a 100cc or do we need to add the small piston displacement as well? Being that the small piston is at it's TDC when the big piston is at it's BDC I think we can ignor the little piston's displacement.

Here's something for you to play with Neil. Not sure if it will run on your computer though; it prefers Windows 98 (maybe XP as well) and doesn't like 64bit machines. HCCI.zip

EDIT: if you really want to see the effects, select the dimensions of the small crankshaft and piston such that it gives about half the cubic capacity of the big crank & piston, and then play a little with the gearing and the phasing.

[Grumph]

I looked into all that, copper plate first is just show chrome, no use. Hard chrome must go straight on to the alloy using hydrfluric as an etch. Not nice stuff. Too difficult to use a brass sleeve (on the rod).

If I could get hard chrome on the 7075 rod and run it against a carbon lined bush that would have to be the most frictionless system there is?

Frits, you take the piss, this is New Zealand, no hard chroming onto aluminium, here

Give Steve Winteringham in Invercargill a call. Classic chrome o3 218 3228 I know he does hard chrome. He's a racer too so likely to be sympathetic.
Nicasil on the rod may be a problem - everyone's set up to do it in bores not on the OD...

The moly filled nylon bushes are non abrasive, I'd think simply polished 7075 would be fine to run against.

Throttling...ha, my one experience of a runaway motor - caused by flaking plating on the plugs - was fun to look back on. We tried to choke it to death by squeezing the airbox rubbers but it only stopped when it emptied the float bowls. In your case it's obviously hot enough to vapourise any oil and use it as fuel - Mr Diesel would be proud. It's either shut off anything which it can use as fuel or stop the air supply completely - which may not be easy....

[eldog]

Nickel is too soft. That's why they throw in sand and call it nikasil..

Induction hardened it. Had some bushes recently induction hardened on inside bore only-tricky Japs

[Flettner]

The hard chromed brass liners were succeeded by hard chromed alu liners and then the MB40 came along with linerless chromed bores (guilty, your Honor).
Labyrinth sealing may work but stationary piston rings around the rod have proven to work too.


Nickel is too soft. That's why they throw in sand and call it nikasil.

Here's something for you to play with Neil. Not sure if it will run on your computer though; it prefers Windows 98 (maybe XP as well) and doesn't like 64bit machines. HCCI.zip

EDIT: if you really want to see the effects, select the dimensions of the small crankshaft and piston such that it gives about half the cubic capacity of the big crank & piston, and then play a little with the gearing and the phasing.

Thank you, thats a hard case program. I'll throw some numbers at it.
If I get a chance today I'll make the above mentioned changes and have another go at the HCCI engine, video this time. I would be nice to have some control

[speedpro]

The hard chromed brass liners were succeeded by hard chromed alu liners and then the MB40 came along with linerless chromed bores (guilty, your Honor).
Labyrinth sealing may work but stationary piston rings around the rod have proven to work too.


Nickel is too soft. That's why they throw in sand and call it nikasil.

Here's something for you to play with Neil. Not sure if it will run on your computer though; it prefers Windows 98 (maybe XP as well) and doesn't like 64bit machines. HCCI.zip

EDIT: if you really want to see the effects, select the dimensions of the small crankshaft and piston such that it gives about half the cubic capacity of the big crank & piston, and then play a little with the gearing and the phasing.

Run it in compatibility mode

[Frits Overmars]

The moly filled nylon bushes are non abrasive, I'd think simply polished 7075 would be fine to run against.

Except that the rod will move at incredible speeds and be hot as well. Teflon would not survive there; anything with nylon in it won't stand a chance in hell.

Thank you, thats a hard case program. I'll throw some numbers at it.

So you got it running? Good, then I'll start with the niceties: you'll be able to enter exhaust timing, temperature and pressure of the cylinder contents at exhaust closure (I'll add default values in case you haven't got a clue) and it will spit out pressure and temperature graphs and lists. May take a while though.

[tjbw]

Run it in compatibility mode

I tried XP SP3 compatibility without success, but that was on W10 64 bit

[Grumph]

Except that the rod will move at incredible speeds and be hot as well. Teflon would not survive there; anything with nylon in it won't stand a chance in hell.

Fair enough - I did ask for an estimate of temps...Looks like carbon remains as the best answer. I'm aware of it's load and temp properties - automotive clutch release thrust bearings as an example. But what does it run against best ?

[Flettner]

Except that the rod will move at incredible speeds and be hot as well. Teflon would not survive there; anything with nylon in it won't stand a chance in hell.

So you got it running? Good, then I'll start with the niceties: you'll be able to enter exhaust timing, temperature and pressure of the cylinder contents at exhaust closure (I'll add default values in case you haven't got a clue) and it will spit out pressure and temperature graphs and lists. May take a while though.

Hey, you got me at "haven't got a clue"

Thank you for your help, I'll need every bit.

[Flettner]

Fair enough - I did ask for an estimate of temps...Looks like carbon remains as the best answer. I'm aware of it's load and temp properties - automotive clutch release thrust bearings as an example. But what does it run against best ?

How about that, we can't hard chrome to aluminium but we can Titanium Nitride alloy parts

Anyway the man at the Titanium Nitride place says that running against a carbon surface will be about best. Add a fine layer of oil and that will do the trick.
Also says that running the 7075 with Titanium coating against 4140 steel nitrided (the bigend) (with oil pressure feed) will make a good bearing.

This all sounds too good to be true, you know what they say.

[Grumph]

How about that, we can't hard chrome to aluminium but we can Titanium Nitride alloy parts

Anyway the man at the Titanium Nitride place says that running against a carbon surface will be about best. Add a fine layer of oil and that will do the trick.
Also says that running the 7075 with Titanium coating against 4140 steel nitrided (the bigend) (with oil pressure feed) will make a good bearing.

This all sounds too good to be true, you know what they say.

Too bloody easy...

[ken seeber]

I've been thinking about the HCCI engine again, one suggestion (on another forum) is to use an exhaust gate (valve) to throttle the exhaust not the inlet, leaving the inlet open still. Put the carb back on and just move the needle up and down (no throttle piston) ??? See what happens I guess.

Neil, been thinking a bit about the HCCI (we don't want to see you killed at all) and the sliding cylinder engine, the thing they have in common is that the mass flow thru the engine is being controlled by something other than the inlet:
a. The exhaust valve for the HCCI as you say
b. The significantly lowered transfers for the sliding cylinder

So, what I was going to do was to chuck on a CV carb, with the butterfly held open or removed. This would then passively supply the mixture. For sure there will be some mucking about getting the carb settings right. Probably made worse by the fact that in nearly every case they were used on 4 strokes. For our application, where I intend to initially focus on low load operation and therefore it'll be just on the idle circuit, adjusting this mixture shouldn't be an issue.

Does anyone know which common bike might have used a smallish CV carb, say 20/25 upwards?

[WilDun]

How about that, we can't hard chrome to aluminium but we can Titanium Nitride alloy parts

Anyway the man at the Titanium Nitride place says that running against a carbon surface will be about best. Add a fine layer of oil and that will do the trick.
This all sounds too good to be true, you know what they say.

Well, there you go - just ask the right people! - which will now take precedence, the first flight with the new engine or the straight line engine? - you've got a very full diary!