The Bucket Foundry

[mr bucketracer]

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.

who was the nice guy that put you on to them (-; lol

[Flettner]

who was the nice guy that put you on to them (-; lol

Yes, thank you.

This thread is a varitable smorgasbord of ideas, thank all.

[husaberg]

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?

GY6 Honda scooters and the Chinese versions of them.

http://www.ebay.com.au/itm/ATV-Quad-...-/251254862471
here are the various sizes and dimensions
https://sites.google.com/site/motorp...tor/moped-carb
Yamaha SRV250 have 26mm downdraft ones as well.
The 250 Fours have 28-30mm CV carbs

[Flettner]

O well, I guess I deserved that. The Yamaha AG 100 piston split in two, almost. After a good hard high speed run. I was trying to get some sort of control before I videoed it but too late now.
Fixes
1 Replace the piston with a forged one

2 Water cool the head as it gets hot. Probably aiding and abetting early combustion as the head gets hotter.

3 Needs the high speed small piston set up ( oval gears ) to get a more accurate combustion point, at the moment it's all happening a bit early but because of the need for high compression I don't have much choice with this setup.

4 I see the crank case is full of oil, maybe as the engine speeds up it's pushing too much oil into the combustion chamber causing it to hydraulic? At first when it stopped suddenly from high speed I thought it had seized as it stopped so fast. Perhaps thats what did the damage? No signs of seizure. A dry top end would be nice (Ryger).

5 Where did I put that supercharger?

I'm sorry, I was so ashamed of that first video I wanted a decient one to replace it, with me under total control, Ha Ha.

[speedpro]

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

Scooters use small CV carbs - 4T anyway

[Flettner]

Some pictures of the damage, only the Yamaha piston, everything else is still good.
See exhaust runaway gate.

[Flettner]

Little tank was full of Kerosene / oil mix, started on CRC spray can.

[mr bucketracer]

Some pictures of the damage, only the Yamaha piston, everything else is still good.
See exhaust runaway gate.

thanks for the pictures , has open my eyes to a old idea i but revisted , must stop projects to start though lol

[Frits Overmars]

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

My pleasure Neil. Here's a version with a couple more functions. Let me know what else you need.
HCCI.zip

[Cheesy]

Just out of curiosity is the TiN a PVD or a CVD process? Many years ago I was playing with this stuff on piston rings and testing it against arc sprayed / plasma sprayed coatings for cylinder liners

[Flettner]

My pleasure Neil. Here's a version with a couple more functions. Let me know what else you need.
HCCI.zip

A sack full of money?

Went scavenging through Blackwood Yamaha's rubbish bin and found a new (ish) piston, not forged but you know what beggers get.
Will make the mods I can for now, drain for the sump, water cool the head.

[J.A.W.]

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

1974 Suzuki GT380 is a candidate as a donor, being a 2T triple that used smallish CV carbs ( & for `74 only).

[Flettner]

No success, after much thought It would seem I've done the wrong thing. I have a better idea with way more control, I think.
And easy to make. Mark two.

[Grumph]

No success, after much thought It would seem I've done the wrong thing. I have a better idea with way more control, I think.
And easy to make. Mark two.

Be careful - if we don't hear from you again, that would make a splendid epitaph.
Just as well you're not a bomb maker...

[Frits Overmars]

No success, after much thought It would seem I've done the wrong thing. I have a better idea with way more control, I think. And easy to make. Mark two.

Apart from the exhaust pipe that you're going to need anyway and that would prevent the engine from inhaling oxygen through the biggest port?
A decent pipe can markedly raise the cylinder pressure at exhaust closure and that will change everything that happens further in the cycle.
Like how much compression you need, and when you need it.

PS: after seeing the pictures of your HCCI head I understand why the 30,5 mm bore and 8 mm stroke. I knew there would be a good reason for it .