Author Topic: Everyone should build an engine, right?  (Read 8471 times)

Online John Hill

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Everyone should build an engine, right?
« on: February 19, 2009, 05:35:41 PM »
Now that I have a lathe, a hacksaw and a few hammers I should be able to build an engine, right?

It would have to be something simple and it cant be some tiny precision thing as such has never yet emerged from the lair of The Artful Bodger.

So how about an atmospheric engine?  (aka flame licker, flame gulper, etc)

I have in mind something with, say, 75mm bore, single cylinder and a single spring valve covering the head orifice.  The cunning bit is that I would use two cams to operate this valve, one to open and another to close so that the cycle can be adjusted for best running.

Now, as far as I can understand these engines rely on the ingested hot gases being cooled by contact with the cylinder walls to cause contraction and the power stroke under atmospheric pressure.  Considering that the ratio of volume to cylinder surface area changes with diameter does that mean a larger engine would be less likely to run?

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bogstandard

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Re: Everyone should build an engine, right?
« Reply #1 on: February 19, 2009, 05:55:53 PM »
Actually John,

Flame lickers (correct name, vacuum engine) were used full sized in the 19th century. But because of their very low power output, they quickly disappeared from use.

I have seen a vertical one running at a steam fair, that must have had a piston about 2" to 3".

Send me an email, and I will send you a set of vertical engine plans to show what is required, and you may be able to scale it up.


John

Online John Hill

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Re: Everyone should build an engine, right?
« Reply #2 on: February 19, 2009, 06:03:02 PM »
Well John I am hoping for at least enough power to turn its flywheel!
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bogstandard

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Re: Everyone should build an engine, right?
« Reply #3 on: February 19, 2009, 07:04:13 PM »
This is mine



BTW, you don't know what you are letting yourself in for. They are a real pig to set up and getting to run correctly. But once done, away they go.

John

Online John Hill

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Re: Everyone should build an engine, right?
« Reply #4 on: February 19, 2009, 07:18:00 PM »
I figured they would be a bit toucy John, that why my design includes variable valve timing.
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bogstandard

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Re: Everyone should build an engine, right?
« Reply #5 on: February 19, 2009, 07:46:17 PM »
John,

Quote
as far as I can understand these engines rely on the ingested hot gases being cooled by contact with the cylinder walls to cause contraction

Actually, you normally have to get the cylinders warmed up before they will run. By flicking the engine over every few seconds, about 10 to 15 mins. I warm mine up with a blowtorch for 30 secs each cylinder, leave for 30 secs to absorb the heat and away it goes.

John

Offline SPiN Racing

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Re: Everyone should build an engine, right?
« Reply #6 on: February 20, 2009, 04:24:43 AM »
Very very cool engine!

Or hot?

Im working towards an engine.

Once I get all my tools made.. I will prolly do a pre-cast engine.. oscilator, or coke bottle.
Then if Im really motivated.. and mentally ready.. I MIGHT try a flame eater..  They are seriously neat.

SPiN Racing

Online John Hill

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Re: Everyone should build an engine, right?
« Reply #7 on: February 20, 2009, 02:39:34 PM »
Bogs has been kind enough to send me some of the vital information regarding 'hot gas ingestion engines' and I feel I have a reasonable grasp on the principles now, thanks Bogs.

I dont think the Artful Bodger's workshop is really the place to produce a fine piece of miniature engineering so IF (repeat IF) I build an engine it will be a reasonable size, something that will require two hands and a bit of huffing and puffing to move around.  It might even have a lot of wood in it, then I can all it the 'Wooden Ingin', or sumfink ::)
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Offline miken

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Re: Everyone should build an engine, right?
« Reply #8 on: May 23, 2009, 05:21:03 PM »
Here are some gentlemen building some rather large engines

http://www.shipsnostalgia.com/guides/William_Doxford_and_Sons#The_Manufacturing_Process

I suspect your lathe might not be quite as big as these>

Mike

bogstandard

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Re: Everyone should build an engine, right?
« Reply #9 on: May 23, 2009, 05:33:46 PM »
John,

Seeing as how this post has been reopened, and you were on about something a little larger, Ray Hasbrook sells some very reasonably priced plans for making a few larger engines out of generally available materials.

They might be a bit more in your line.

http://hasbrouck.8m.com/index.htm

If ever I had the urge to make one, I think #10 would be at the top of the list.


John

Online John Hill

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Re: Everyone should build an engine, right?
« Reply #10 on: May 23, 2009, 05:44:02 PM »
Thanks John, Mike  I think they might be Doxfords that I hear going through the straits some nights!

John, I quite likely will not be attempting an engine for a little while just yet,  the first step will be to actually modifiy two bits of metal so that they fit each other!  :lol:
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Online John Hill

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Re: Everyone should build an engine, right?
« Reply #11 on: May 23, 2009, 08:54:29 PM »
#10 you say John?  It sure looks achievable and at 2HP I could use it to power my lathe! :lol:
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Offline zeusrekning

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Re: Everyone should build an engine, right?
« Reply #12 on: May 23, 2009, 10:42:34 PM »
Here are some gentlemen building some rather large engines

http://www.shipsnostalgia.com/guides/William_Doxford_and_Sons#The_Manufacturing_Process

I suspect your lathe might not be quite as big as these>

Mike


Absolutely awesome pictures man, Its so nice to see suck clear images and so much of the processes covered. And I have to have that ball turner.
Tim



Offline CrewCab

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Re: Everyone should build an engine, right?
« Reply #13 on: May 24, 2009, 03:23:57 AM »
Here are some gentlemen building some rather large engines

http://www.shipsnostalgia.com/guides/William_Doxford_and_Sons#The_Manufacturing_Process

Mike

 :thumbup: Great link Mike, thanks

CC

Offline TFL45

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Re: Everyone should build an engine, right?
« Reply #14 on: May 24, 2009, 12:45:21 PM »
Here are some gentlemen building some rather large engines
http://www.shipsnostalgia.com/guides/William_Doxford_and_Sons#The_Manufacturing_Process
Mike

Thanks for the link, Mike. :thumbup:

Newbie question for the day: How were those iddy-biddy bits for the crankshaft fixed to each other? Don't see any set screws or a large, economy-sized bottle of Loctite about, and it doesn't appear that they were using heat. Taper fit? (And I though built-up might be the easy way out!)

Floyd
TFL45

There's no need to be precise if you don't know what you're talking about!

Offline SPiN Racing

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Re: Everyone should build an engine, right?
« Reply #15 on: May 25, 2009, 07:21:07 AM »
The pics in there are like a Where's Waldo at first!  I was looking at things going.. hmmmmm neat.. wonder what these are..... then I saw some tiny little man next to one of the parts and had to go back and look closer at them!!!

I have never in my life even concieved of an engine as large as those.

I have been on ships.. WWII ships and things.. but none of them had engines I percieved to be that big.  I coulda been a dumb kid and not grasped it... But man oh man that is a BIG engine.. and crank.

The tooling... is astoundingly large...
SPiN Racing

bogstandard

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Re: Everyone should build an engine, right?
« Reply #16 on: May 25, 2009, 07:28:33 AM »
Spin,

This is the largest one, at this time.

http://people.bath.ac.uk/ccsshb/12cyl/

A little large to fit in your Mazda.


John

« Last Edit: May 25, 2009, 07:30:38 AM by bogstandard »

Offline SPiN Racing

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Re: Everyone should build an engine, right?
« Reply #17 on: May 26, 2009, 01:55:50 AM »
5 MILLION FtLBs of torque....  Thats just crazy!!!!  :lol:



Although looking at the engine it appears to have been well thought out. Exceeding 50 percent BSFC is pretty damn good.


Amazingly huge engine. I am going to have to make a side trip to a big port one of these days when Im in the vicinity of one. Port of Tampa I dont think is big enough... Miami, or Cape Canaveral possibly. Jacksonville possibly.
SPiN Racing

Offline DavesWimshurst

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Re: Everyone should build an engine, right?
« Reply #18 on: May 27, 2009, 03:19:04 PM »
Perhaps a smaller engine,
This is the thimble engine designed by J Senft.  I couldn't find a suitable thimble so spun one in copper.  The bore and stroke are each 1/16 inch.  The piston is brass as I had trouble drilling a 0.020 inch hole for the crank pin in the specified stainless steel.



The vibration causes it to turn on it's stand, otherwise it's hard to see that it's running.
Dave