As a non-engineer type my only involvement with momentum, power and so forth has been with applied mechanics at A Level maths. All these poundals, foot-pounds, foot-pounds-weight and pounds-weight-feet, etc. didn't seem at the time to have much relevance to the real world in the 1960s, and Kwatts meaned only electric kettles and washing machines to me, nothing to do with engines. All I can remember from school about Horsepower was that one was equal to 550 somethings-or-other per hour (but then a 40 year gap may have confused my recollections). On the other hand my dad says horsepower has no absolute relation to engine power it is an arbitrary taxation calculation which was based on either engine cylinder bore or stroke, but illogically not both. Dad claims to have had a 1939 14HP car with a 1770cc engine producing about 50 BHP. On reading about these one and a half tonne or more monster vintage engines producing 18 or 19 meaty horsepower easily able to drive loaded boats it seems inconsistent with the 25 meagre horsepower produced by the japanese lawnmower engine sitting under the floor of PM. Clearly my 25 HP (or is it BHP?) is very different from the 20 ish HP from an SR or JP2 or whatever. What I would like to know to give a real comparison is what is the consistent measure of the effective power or 'GRUNT' (to give it another name) that an engine has. I don't really understand the efficiency relationship between a classic engine delivering 15 HP at 1000 revs or less and mine delivering 25HP at 3,500 revs. It seems the recommended prop. size gives a better measure of potential GRUNT than HP, as it appears from what I read one of these big jobs can swing an 18 x _ _ prop, whereas mine should only be coupled to about a 15 x 10 prop. Is there some light at the end of this tunnel Mr Brunel? Arthur Naylor nb Confused of Rotherham
[Non-text portions of this message have been removed] ------------------------ Yahoo! Groups Sponsor --------------------~--> Something is new at Yahoo! Groups. Check out the enhanced email design. http://us.click.yahoo.com/SISQkA/gOaOAA/yQLSAA/ygtolB/TM --------------------------------------------------------------------~-> Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/canals-list/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
