Search found 284 matches

by gondolier88
Sat Jan 30, 2016 7:54 pm
Forum: Technical - Engines and Boilers
Topic: 90 deg-- 180 deg crank
Replies: 28
Views: 14242

Re: 90 deg-- 180 deg crank

Apologies for autocorrect 'could' should have been 'couldn't' in my last post. I see now that the con rod on the centre cylinder is longer than the other two, I'm looking on my phone so I can't tell from the end elevation what the anglular offsets of the cranks are- do you know? Do you know if the c...
by gondolier88
Fri Jan 29, 2016 11:29 pm
Forum: Technical - Engines and Boilers
Topic: 90 deg-- 180 deg crank
Replies: 28
Views: 14242

Re: 90 deg-- 180 deg crank

TahoeSteam wrote:Herreshoff's steeple triple-expansions had 3 cranks and they weren't at 120* speration
I'm interested how a steeple triple could have three cranks- I don't know the Herreshoff engines well, have you got a link or a photo?

Greg
by gondolier88
Thu Jan 28, 2016 9:16 pm
Forum: Technical - Engines and Boilers
Topic: 90 deg-- 180 deg crank
Replies: 28
Views: 14242

Re: 90 deg-- 180 deg crank

For balance on a twin you can't beat a 90deg. opposed V configuration- they only require one crank so there are zero dead spots and as the engines are pushing in slightly opposed directions they cancel out each other's reciprocating mass. There have been successful v-twin simples and compounds made...
by gondolier88
Thu Jan 28, 2016 7:53 pm
Forum: Technical - Engines and Boilers
Topic: 90 deg-- 180 deg crank
Replies: 28
Views: 14242

Re: 90 deg-- 180 deg crank

For balance on a twin you can't beat a 90deg. opposed V configuration- they only require one crank so there are zero dead spots and as the engines are pushing in slightly opposed directions they cancel out each other's reciprocating mass. There have been successful v-twin simples and compounds made ...
by gondolier88
Sat Jan 23, 2016 10:39 pm
Forum: Technical - Engines and Boilers
Topic: Appropriate hullsize and prop for 25 HP engine
Replies: 21
Views: 15300

Re: Appropriate hullsize and prop for 25 HP engine

Frank, An interesting proposition! I haven't built a longship, but I have sailed on and studied the construction of Viking ships and have a few issues with what you propose; 1- At 40ft the freeboard of a longship would only be around 18 inches- this sounds ok, but in reality, they have odd stability...
by gondolier88
Thu Jan 21, 2016 5:56 pm
Forum: Technical - Engines and Boilers
Topic: Lubrication free condensing?
Replies: 51
Views: 23090

Re: Lubrication free condensing?

O-rings have been used as piston rings, but just because they work does not mean they are a good solution- in order for the o-ring to be able to withstand reciprocating motion it must have no side play whatsoever or it malforms and runs the risk of tearing. So let's think what a correctly fitting o-...
by gondolier88
Wed Jan 13, 2016 9:44 am
Forum: Technical - Engines and Boilers
Topic: Correct construction of firepit Scotchboiler
Replies: 8
Views: 4716

Re: Correct construction of firepit Scotchboiler

Frank, The grate should never be level with the firedoor- for the same reason it makes it easy to rake out, it also makes it easy for the fire to fall out should you be in a heavy swell or ground in shallow water- the last thing you want is your fire bed on the engine room deck! Looking at the grate...
by gondolier88
Tue Jan 12, 2016 8:32 pm
Forum: Technical - Engines and Boilers
Topic: Appropriate hullsize and prop for 25 HP engine
Replies: 21
Views: 15300

Re: Appropriate hullsize and prop for 25 HP engine

The old Royal Navy steam pinnaces are a good basis for a boat that you are describing- there are couple for sale at the moment; http://www.apolloduck.co.uk/feature.phtml?id=456115 Double diagonal teak on oak, with room for a big prop. They can be fitted out in all manner of styles and could happily ...
by gondolier88
Tue Jan 12, 2016 8:24 pm
Forum: Technical - Engines and Boilers
Topic: Appropriate hullsize and prop for 25 HP engine
Replies: 21
Views: 15300

Re: Appropriate hullsize and prop for 25 HP engine

Nowhere near Amsterdam- she's in Australia! Remembered seeing a short article about her, possibly in Classic Boat magazine. Anyway, here is her website;

http://www.preana.org/Default.aspx
by gondolier88
Tue Jan 12, 2016 8:19 pm
Forum: Technical - Engines and Boilers
Topic: Appropriate hullsize and prop for 25 HP engine
Replies: 21
Views: 15300

Re: Appropriate hullsize and prop for 25 HP engine

Lovely boiler there Frank! It's a dry-back Scotch boiler with wet legs in the primary smokebox to increase efficiency- the best arrangement where the complexity of constructing wet-back boiler renders it out of budget range. It also makes re-tubing a far easier proposition should you ever have to. W...