Quote:
4000rpm 24 knts 27.60 mph 9.5 gph 2.91 mpg
4500rpm 28.5knts 32.78 mph 11.0 gph 2.98 mpg
5000rpm 33 knts 37.95 mph 16.0 gph 2.37 mpg
5500rpm 36 knts 41.40 mph 19.5 gph 2.12 mpg
6000rpm 39 knts 44.85 mph 22.5 gph 1.99 mpg
http://www.classicseacraft.com/forum...rev=#Post45415
************************************************** ******************************
To answer this thread I run 22" ss props on my twin 115 Suzuki 4 strokes and I get 28mph and 10.5gph at 4k rpm's for about 2.7MPG and that is with a full tank and 3 people. Max speed 38kts at 6300 rpm's. I may go to 24" props to drop the rpm's down to 5900 or so.
http://www.classicseacraft.com/forum...rev=#Post51742
|
I switched out my 22" props for 24" SS props on my twin 115's. The bow now runs a little flatter which I like but I lost a little trimability. My cruise speed is now about 2kts higher and top speed comes in at 39kts(hit 40 once) at 5900+rpm's. This is on a 23 CC with an enclosed transom and bracket. To answer this thread's initial question about the 140's since it is essentially the same block as the 115 (slightly bored out) and a higher gear ratio, my best guestimate is 2mph better at cruise and wot.
If I had to buy new motors I would go with the 300 Suzuki. From everything I have read, mpg would be in the mid 3 range and top speed about 44kts(50mph) A guy on THT just put a 300 on his 25 bluewater and is really getting great fuel numbers, even better than with the 250 Suzi.
Weight is an issue also, my 115's with ss props come in around 430 each vs. 630ish for the single 300. When I repower, I will go with a single 300. The 115's have been practically flawless. 45 miles offshore I never wonder "what if"