speed numbers on a v-20

[cterrebonne]

Originally Posted by bradford

No trim tabs, I've got a hydrofoil on the cavitaiton plate.

those help with planning the boat really good, with tabs with the 225 it should keep the rear end stable but thats a long ways away i still need to finish the hydrostream

[bcmarinamanager]

My CC has gotten up to 45mph on GPS coming down my creek one evening when it was glass. I had the center panel on my T-top on and my side curtains rolled up. I'm running an old as dirt 1992 2.3l 200hp Mercury ob. No tabs, and it was before I got my foil on the engine. I think now i might hit 47-48, I haven't actually tested it with the ideal conditions yet. You should get at least 50 mph. In reality, 25 more horses won't give you a big gain in the top end like it does in a car. You'll shoot out of the hole a bit quicker though.

[bigshrimpin]

You'd have to turn at least 5800+ rpm with a 19 pitch prop to see 50mph.
http://www.go-fast.com/Prop_Slip_Calculator.htm

That's not an easy thing to do, cause most 225's are big heavy 3.0L + motors. If you find a Yamaha 2.6L 225 or a excel or 220 special . . . Those will hit 50+ with the v20. I actually think the boat would be slower with a stock 3.0L Merc 225 vs. a 2.5L merc 200. 200hpdi . . . would probably hit 50mph. The extra 5mph takes exponentially more HP to reach once you get above 45 mph.

[cterrebonne]

[QUOTE=bigshrimpin;115427]You'd have to turn at least 5800+ rpm with a 19 pitch prop to see 50mph.
http://www.go-fast.com/Prop_Slip_Calculator.htm

That's not an easy thing to do, cause most 225's are big heavy 3.0L + motors. If you find a Yamaha 2.6L 225 or a excel or 220 special . QUOTE]


you must be joking? yamaha's are dogs compared to mercs and omc's brp's.

[spareparts]

I'd have to dissagree as well, the 3.0 L Mercurys will run if you prop them right, they will spin a big blade surface prop that will bog most high reving smaller motors. My 81 V has a 85 2.4L 200 carb motor, it came with a 21 P, don't know any numbers on it yet as I haven't put it in the water yet.

[bigshrimpin]

Here's wellcraft's numbers for a 1996 v21 with a 2.5L Mercury 200. You'd be lucky to get more out of the 3.0L . . . and with the open transom on the v20 . . . I personally wouldn't want the extra weight of a large displacement 225.

Spares the 2.4L 200 with fingerports is my favorite old two stroke motor. I think you'll see high 40's with that power.

[bigshrimpin]

1993 2.5L merc 150 vs. 1993 2.6L yamaha vertical reed 150

[bigshrimpin]

cterrebonne - Find a Merc 245 or 260 and you'll be in bid'ness.
Even though I perfer mercs . . . those 220 specials with the horizontal front, big carbs, and compression up around 130/140psi those motors are pretty strong :)

I just think it's gonna be difficult to get to 55 even with the little pad on the bottom of the v20.

[cterrebonne]

thanks for posting those spec sheets on the v20 big shrimpin. i noticed the specs and that yamaha compared to the merc is a dog. the merc 200 hit 50.4 which isnt bad at all but i own a 200 2.5l merc and compared to the 3.1 omc brp block its a sissy (which i also own). its crazy because when putting then both on the dyno its not even close between the two engines. but i do agree with you shrimpin 55 will be hard even with the 225 ficht.

[Pipe_Dream]

When we repowered and the engine had less than 10 hours on it, we eeked out a 50 mph reading, wide open with the engine trimmed waay up. I've not been able to reproduce that since then, even just a few weeks ago with new bottom paint. Mid-40s seems to be the best I can do, but as was said earlier it feels pretty dicey. A cross-wind gust feels like it's going to put her on her side! But I rarely run her anywhere close to wide open, unless it's a calm day and I just want to let her stretch.