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Re: To get a triple

Posted: Sat Nov 21, 2009 5:25 pm
by barts
Here's a picture of a really nice steeple compound... this is the fastest boat around here by a good bit:

Image
http://www.oldtimetech.com/
I'll get better engine pictures of our local boats next year....

Uniflow engines prob. operated at higher RPM since they were designed later on; there's nothing
intrinsic in the design to suggest that they need higher RPM to function. They do require a larger
cylinder, but only one of them....

As far as I know, there aren't any commercial steam launch uniflow designs; such complications
aren't really necessary in our small plants since the cost savings in fuel for a pleasure boat that's operated
often much less than 100 hours/year are minor. I hope to build one for a larger ~35' boat, though...

- Bart

Re: To get a triple

Posted: Sat Nov 21, 2009 7:19 pm
by artemis
Ralph B wrote:It's not so much tradition that interests me as the look...steeples don't grab my eye...
You mean this steeple that doesn't grab your eye? :shock:
Image
Photo courtesy of Dick Vennerbeck

Re: To get a triple

Posted: Sun Nov 22, 2009 12:42 am
by mcandrew1894
OK

Here's some engine pornography....triple style


100 Hp Seabury restored by the "Steam Team" at Mystic.....One of my better associations :D
Image
The LP is 11 1/4" bore

Meant for high speed.

Dave

Re: To get a triple

Posted: Sun Nov 22, 2009 1:27 am
by csonics
That's one beautiful machine!

Re: To get a triple

Posted: Sun Nov 22, 2009 11:16 am
by steamboatjack
Hi,
Engine speed is really a function of stroke length to get a reasonable piston speed, therefore an engine should be built to run as fast as the maximum piston speed allows assuming other factors such as inbalance do not pose a problem.
Most steam launch owners operate way below the maximum piston speed, this of course means they sacrifice power for looks. About 500 feet/min. can be considered a maximum mean piston speed which means a 4 inch stroke engine could run at 750 rpm.
This would however throw the oil around somewhat assuming conventional lube systems are used.
Uniflow engines of the double acting kind are no different.
I did start a three cylinder uniflow design but I'm afraid it got left in the "one day" cupboard with a lot of other stuff. There are two uniflow boats in UK which I know about but they are one offs.

regards Jack

Re: To get a triple

Posted: Mon Nov 23, 2009 7:43 am
by barts
artemis wrote:
Ralph B wrote:It's not so much tradition that interests me as the look...steeples don't grab my eye...
You mean this steeple that doesn't grab your eye? :shock:
Image
Photo courtesy of Dick Vennerbeck
That of course is the sister (brother?) engine to the one in Jerry's boat... and it recently grabbed the "fastest boat in the lake" title back east...

Triples are neat from a "monkey motion" standpoint... but man, that's a lot of parts to make and care for!

- Bart

Re: To get a triple

Posted: Sun Nov 29, 2009 12:20 am
by fredrosse
I built a uniflow engine to generate the electricity for my home, using a combination piston valve-poppet valve for admission, with conventional uniflow exhaust ports. The engine was very efficient, and produced a maximum of 4.64 Horsepower at 1500 RPM, but only ran at 600 RPM for most of its life. There is an ASME paper about this domestic heat-power unit, I will forward a copy if you like.

Re: To get a triple

Posted: Sun Nov 29, 2009 4:17 pm
by mcandrew1894
I would really like a copy of that paper!

Regards,

Dave

Re: To get a triple

Posted: Sun Nov 29, 2009 6:01 pm
by 87gn@tahoe
I would really enjoy a copy as well.

wes

Re: To get a triple

Posted: Sun Nov 29, 2009 8:48 pm
by farmerden
Ditto on that! Did you burn wood? Den