Author Topic: flame gulper material question  (Read 2411 times)

Offline jim

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flame gulper material question
« on: December 07, 2009, 01:18:42 AM »
just a quick question, i thinking about having a go at making one of these, but just wondering about material. could ally be used for barrel and piston?
just wondering as i'd have thought it disipated heat better than cast iron?

thanks jim
if i'd thought it through, i'd have never tried it

bogstandard

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Re: flame gulper material question
« Reply #1 on: December 07, 2009, 01:41:00 AM »
Jim,

I think it is all to do with what plans you make it from. These engines are notoriously difficult to get running, and a major change like metal the bore and piston are made from could prevent the engine from ever running.

I used cast iron for the one that I built, purely because Jan Ridders, the designer, stated that the carbon content of the cast iron was the only lubrication that was needed on the engine. I do know that other designs do use lubrication, and in those circumstances, then I think ali could be used. But don't quote me on it.

I would tend to stick with what the designer recommends, then you know you will at least have a chance at getting it running, because he has already done it.


John

Offline jim

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Re: flame gulper material question
« Reply #2 on: December 07, 2009, 03:34:57 AM »
thanks for the advice John.

i think i'll learn to walk before i run. I think a better plan is to make it out of cast iron and then replace the barrel and piston with ally once it works, at least then i'll know if its viable.

next question, we use a lot of cast iron at work, there is plenty of scrap (blow holes/casting faults), is there any reason i can't just chop a casting up and make some billets out of it or should i just get some cast bar??

thanks again, Jim
if i'd thought it through, i'd have never tried it

Offline sbwhart

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Re: flame gulper material question
« Reply #3 on: December 07, 2009, 07:23:20 AM »


next question, we use a lot of cast iron at work, there is plenty of scrap (blow holes/casting faults), is there any reason i can't just chop a casting up and make some billets out of it or should i just get some cast bar??

thanks again, Jim

The scrap stuff will be OK you'll just have to be carful not to get the top end of the riser or sprue where all the slag collects, chopping up the casting will be fine as well. Getting hold of scrap cast iron is a bit of a problem it not used a lot now, they mainly use cast steel, John,s just given me a length of cast iron salvaged from some old window sash weights, that machine great.

Getting through the hard outer skin on cast iron is the biggest problem, you have to start on a clean broken edge with a cut that takes you below the skin once your through this you should be OK as long as its free from hard inclusions.

Cheers

Stew

A little bit of clearance never got in the road
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Location:- Crewe Cheshire

Offline NickG

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Re: flame gulper material question
« Reply #4 on: December 07, 2009, 07:50:34 AM »
I know everyone is keen from making things from recycled stuff but I am converted. For the amount it cost to buy the bits of known, good quality metal (pretty cheap) I won't be hunting around any more or trying unknown stuff. You could spend more in ruined cutters and certainly in the time it takes.

I doubt if the heat dissipation of the aluminium would contribute much to the running of the engine. The coefficient of friction I would have thought is more for ali, so any advantage would be eaten away at by friction.

Having said that, I have seen designs with plain bearings and I think brass cylinder or piston that worked though. As John said, do what is known to work, then you can eliminate that variable when troubleshooting!

As you've probably seen I'm struggling to get mine running and all the tests seem to work out ok.  :scratch:

Nick
Location: County Durham (North East England)