Prop Selection

[Duke01]

Okay, thanks for following up...

Duke

[reelapeelin]

I was thinking the 1920lb spec referred to dry hull (no gas in the tank and no motor)...earlier hulls allowed 235 HP, but later hulls like my '95 V21 only allowed 200 which always seemed odd to me. My best prop experience was a 17x15.25x3 SS by Power Tech...on a 150 Honda topped out at 42 and easily and economically cruised at 30. Generally a 4 blade prop has stern lifting characteristics which is good cuz V20s ride a bit bow high and like Ferm sez, may drop a couple of MPH off the top end. A good friend of mine has a 250 Verado on a 24 Everglades and loves his 4 blader...

[THEFERMANATOR]

Originally Posted by reelapeelin

I was thinking the 1920lb spec referred to dry hull (no gas in the tank and no motor)...earlier hulls allowed 235 HP, but later hulls like my '95 V21 only allowed 200 which always seemed odd to me. My best prop experience was a 17x15.25x3 SS by Power Tech...on a 150 Honda topped out at 42 and easily and economically cruised at 30. Generally a 4 blade prop has stern lifting characteristics which is good cuz V20s ride a bit bow high and like Ferm sez, may drop a couple of MPH off the top end. A good friend of mine has a 250 Verado on a 24 Everglades and loves his 4 blader...

Some hulls run faster with 4 blades, each boat is different. My 19 carolina skiff picked up almost 3 mph going from a 3 blade 17 pitch solas to a 4 blade 17 pitch solas. My hydrasports liked a large diameter 3 blade. Kept the same top end, but picked up big time in the cruise area. Many people would be shocked if they got with aprop shop and tried out some different props. Many think thete boats have quirks to them that may just be the prop. Others have fallen in love with there boats again after repropping. You just don't know unless you've taken it out and trief a half dozen different props. Sometimes all you need is a pitch change of just an inch to transform there boat, and other times they need a completely different prop. 4 strokes seem to do best with props that provide extra stern lift due to there heavier weights, so they like 4 blades.

As to the drop in HP for the V-21, it had to do with the euro transom change. Boats with a flat transom were rated at 235(except early hulls before the 235 existed), but the v-21 euro transom was only 200hp. And it also had to do with the change from flywheel hp ratings to propshaft. The old 235's were flywheel rated, and became a 185hp when they went to prop shaft rating.

[Destroyer]

Originally Posted by THEFERMANATOR

As to the drop in HP for the V-21, it had to do with the euro transom change. Boats with a flat transom were rated at 235(except early hulls before the 235 existed), but the v-21 euro transom was only 200hp. And it also had to do with the change from flywheel hp ratings to propshaft. The old 235's were flywheel rated, and became a 185hp when they went to prop shaft rating.

If one looked at the Euro transom design of the V21's from the inside it became evident why Wellcraft dropped the HP max. The bubble of the transom was not IMHO fully secured to the hull. There was a gap of almost an inch on both sides where the bubble came thru the main flat transom up to the first stringer. Why they didn't fill/glass in that gap and attach it to the stringer remains a mystery to me to this day, but when I removed the floor of my V21 to replace the rotted wood underneath and saw the gap it was one of the first things that I strengthened with filler and glass. I think that Bgreene also has strengthened his V21 the same way after learning of it.

[THEFERMANATOR]

Originally Posted by Destroyer

If one looked at the Euro transom design of the V21's from the inside it became evident why Wellcraft dropped the HP max. The bubble of the transom was not IMHO fully secured to the hull. There was a gap of almost an inch on both sides where the bubble came thru the main flat transom up to the first stringer. Why they didn't fill/glass in that gap and attach it to the stringer remains a mystery to me to this day, but when I removed the floor of my V21 to replace the rotted wood underneath and saw the gap it was one of the first things that I strengthened with filler and glass. I think that Bgreene also has strengthened his V21 the same way after learning of it.

I was the one that posted about that about 10 years ago after I looked at a v-21 that was a theft recovery, had the deck ripped out, and seen it. I was shocked when I could see light coming through the glass.

[steplift20]

I also have a 78 with a 1988 150 Mercury and to me the best prop is 15 X 17 aluminum
I had a 13 X 19 s.s. And the would give me cavitation I'm very happy with my correct prop I think you will be too

[Duke01]

Thanks again for the input. I need to make a correction to my existing prop number that I noted earlier. It is a 48-78120-19 (not 18). I think my first step is to purchase an aluminum replacement (matching existing) and then a test on the water with a gps to obtain an accurate speed reading. I will follow-up with you all, but it will not be until July since I have a list of projects to complete before launch.

Thanks, Duke

[Destroyer]

Originally Posted by THEFERMANATOR

I was the one that posted about that about 10 years ago after I looked at a v-21 that was a theft recovery, had the deck ripped out, and seen it. I was shocked when I could see light coming through the glass.

Wow. Thanks Ferm. Of course I was not a member or a visitor here 10 years ago so I never saw that post. I was just speaking of my own personal experience when I ripped the deck out of my V21.. But it's good to know that you saw and posted about it also. Always good to have corroborating evidence. I still cannot imagine what Wellcraft was thinking of when they built the bubble like that. It simply boggles the mind.

[THEFERMANATOR]

I had got all excited when I found a v-21 theft recovery, drove 2 hours to look at it, and man was I let down when I could see under what was torn up. I thought maybe it was just that 1, but others confirmed it on theres too.

[Destroyer]

Originally Posted by THEFERMANATOR

I had got all excited when I found a v-21 theft recovery, drove 2 hours to look at it, and man was I let down when I could see under what was torn up. I thought maybe it was just that 1, but others confirmed it on theirs too.

Completely understandable. Man, that sucks to have driven 2 hours just to see that. I know I was shocked when I saw it. I was all like"WTF"?