Brass or Cast iron

[NickG]

Don't know why there are multiple copies of this question now but I for one would definitely miss the guidance and help of experienced members like John (Bogs) he has a wealth of experience he is willing to share which a lot of people would miss so I hope he reconsiders his last statement. I agree with him, why ask the question, let people take time to advise then ignore it anyway.

Fingers, if I were you I'd use cast iron for both cylinder and piston. If not (and I've tried different materials for said components on a Ridders flame licker as I was daft enough not to ask the question), when it gets hot there will either be too much or too little clearance due to differential expansion, this will cause the engine to either stop running or sieze up completely. That's not to mention the lubricating properties and ease of machining the cast iron.

NIck

 

[Captain Jerry]

I get a lot of help from this forum, most often without even asking. I see questions posted that I might never have thought to ask and there is always a good effort to supply an answer (or a range of answers) from experienced members. I know there are a lot of people like me who rely on this flow of information and experience and encouragement.

This is not a one to one conversation although it seems like it sometimes. This is a one to all conversation and good information freely given is the treasure that keeps it alive.

My personal "Thank You!!" to everyone who participates, either with questions or advice.

Jerry

 

[Cedge]

The nice thing about the forum world is that you can get lots of good information freely for the asking. The terrible thing about the forum world is that you can get lots of good information freely for the asking. That free information is only as helpful as the user allows it to be. Therein lies a major source of frustration of the forum world. The user is free to take as large a drink as he can swallow, but is free not to drink from the cup at all. We answer questions with an eye to making the process easier for the new guy, but we've all been guilty of ignoring good input and opting to see if the "dog bites". I certainly have in the past and most assuredly will do so in the future, should the muse call.

HMEM is a place where we all want to see the new guy do it right the first time, but it also always been a place of patience when it becomes obvious it isn't going to happen. Yup... he'll probably fail, flounder and return to ask the question with eyes and ears more open. Bloody knuckles are great for achieving focused attention. It's all part of the learning curve and it can try the patience of those who've already been there and done that. The trick is to keep the guy from mowing off his fingers before he gets to the focus thing.

Old hands can easily lose patience and find it frustrating. Much of that come from having forgotten much about the place where a new guy exists. Confusion, excitement, over exuberance and lack of successes, all these color his world until he settles down enough to be taught. Many never make it to that point before giving up. Beating him up for being what he is only makes it more likely he'll fail. Patience..... he'll eventually ask a question that shows he's getting it.


Steve

 

[Fingers]

First of all can I take this time to apologize for the multiple post my error I didn't know how to remove it from pictures and videos after i posted it there by mistake.
Secondly may I say, as I am a relativly new member to the forum certainly for posting here .I did not realize the level of guidance which can be achieved here, and i am humbled by the time people have taking to respond to my post. My only regret is that i did not post this question a week before I already had a brass cylinder half bulit in my mind, "The joys of an over exciting newbee" and not the day before I was planning to build it. If i had knowing then what i know from learning listening to all the reply's I most definetly would have made it from cast iron from what I have now digested and taking in, all be it i still have a brass cylinder which i hope will get me a run even if it dose have a short life, i can remake a ci one at a later date.
From listening to all of your remarks and comments i will have to steady myself next time ,
listen , learn , then make.
Not make, listen, and learn the hard way!
Regards j

 

[Cedge]

LOL.... Finger.
It can all be a bit overwhelming and the problem of tunnel vision strikes us all at times. Don't sweat it... it'll come to you if you just keep plugging. I can promise you there are plenty of mistakes in every one of our pasts. Some were larger and more serious or dangerous than your small goof. As long as you heed the safety warnings this place constantly gives off, feel free to make mistakes, break a few tools and fill your own scrap parts box to the brim. Each screw up is a step in the right direction if you learn from it. No harm, no foul.... go and sin no more....(evil grin)

Steve

 

[Fingers]

Thanks Steve
Not to worry il keep on plugging away
Regards j

 

[NickG]

Good points you make there Steve. Good luck with the cylinder Fingers, it looks fantastic by the way, hope it runs just as well but guess you know what to try if not.

Nick

 

[Fingers]

Thanks Nick
hopefully il be posting a running video soon.

 

[Fingers]

Hi Everyone
I just want to confirm all of the above which I am coming to learn the hard way ,brass cylinder and CI piston on a flame licker bad idea! I have found this out on my first attempted run, it was almost turning over just getting some momentum then stop! Dead, I didn't realize the piston was stuck while I kept trying to flick it over, resulting in the timing slipping on the flywheel grub screw. I'm going to try make the bore in the cylinder bigger before I make a new CI one. Moral of the story listen to people with experience who have been there done that,
Regards J

 

[Jasonb]

If there is enough metal you could bore it out and fit a CI sleeve, that way you keep the looks but get the right materials running together. Have a small flange at the head end of the sleeve that fits a recess and the head will hold the sleeve in place.

Jason

 

[Cedge]

J...
Not a total loss. You took away some knowledge you didn't have before. You aren't dealing with any extreme temps with an engine this small, so there might be another option. I'm running a cast cylinder with an aluminum piston in my Duclos Victorian IC engine and have no problems at all. He recommended cast iron rings as first choice but I've used Viton O'rings with success. The aluminum withstands the heat just fine and the rings, even though they are directly exposed to combustion, work well. I see obvious no reason the brass / aluminum combo wouldn't work if you don't want to sleeve the cylinder. The flame source on your engine is external, so I'd think it would see even less stress than an IC engine. Just be sure to hone your bore for a nice friction free fit.
Steve

 

[Fingers]

Thanks lads
Sure enough i don't think I have enough room left to put a sleeve in the cylinder only 2mm either side wall thickness left, Secondly am I understanding correctly to maybe try an alu piston, also i have now only gotten back to stripping it down after it jammed up on me last night ,it seems to me like my CI piston is starting to rust ,surely this cant be normal after just a quick wipe clean it turns freely again.

 

[Jasonb]

Rust would not have formed as it was running are you sure its not brass being worn off the cylinder if its gauling.

Jason

 

[Cedge]

Jason... great minds...eh? Sounds like brass residue here too, especially if he's got direct metal to metal contact.

Steve

 

[Fingers]

Thanks that dose sound a lot more realistic then rust after a few minutes lol .It seems like I don't have enough clearence when i look at the light thru the cylinder it has lots of small scratch marks running parallel straight thru. I might try make the bore a little bigger and see how things go from there ,fingers crossed its my last time in the work shop till the new year ......
Jamie

 

[NickG]

Jamie,

No you are still not understanding - use the same materials for cylinder, piston and valve, we couldn't put it any more clearly.

I've tried aluminium pistons if you read my post, it locked up solid after a few seconds of heat never mind minutes. You are always going to have differential expansion, the flame is right on valve and piston at through the port. i.c. engines work with an aluminium piston and cast iron cylinders because they have the correct clearance in built with rings to make the seal. Rings though cause a great deal of friction relatively speaking and will not work for this type of engine. People don't realise how little power these engines have and how little friction has to be achieved (read Jan Ridders pages again), rings are just not an option.

If you don't want to re-make the cylinder, the only things you can do are to try is graphite piston and valve, should be low friction and make a good seal, not sure about expansion on that but I have heard people have had good results with pistons from this material on flame lickers. Or use the same material as the cylinder as people have said all along.

As I mentioned before, the brown residue is produced from the meths.

Any noticeable clearance and the engine will not run, any noticeable friction and it won't run either. If the materials for piston, cylinder and valve are different one of the fore-mentioned will be compromised as the engine heats up. i.e the clearance between the two will either get bigger or smaller.

Cheers and good luck.

Nick



The scratch marks

 

[Fingers]

Thanks again Nick what can I say, as a beginner I have brass cylinder cast iron piston and a tool steel valve for the 3 above parts all different materials (beginners luck) :-\ lol but hey it stil runs , next time I will put more taught into material choice I now know what will work best together from listening to everyone through this build, I wil keep posted If I need to remake a part, first if and when I do.
Jamie