Building a '93 Caravelle 1750 Classic Bowrider

[Reserector_]

I finally got out for another test run and was blessed with fantastic weather.
Getting it running right is the final step in this complete restoration.
The '93 1750 ran the best ever, so far. 3.0L OMC. 19P x 14.5 aluminum, 3K rpm gave me 35 mph.
I have a 17P I can try next, but mainly I was pleased that the engine was responsive.

 

[Scott Danforth]

what is your WOT RPM that will determine which prop to use.

I had 3 with me all times when I had a 3.0

 

[Reserector_]

3,000 was wide open. I need to verify that the butterfly is actually wide open when the control is all the way forward.

 

[Scott Danforth]

3,000 was wide open. I need to verify that the butterfly is actually wide open when the control is all the way forward.

I would also verify your tach

you should be able to hit 4500 RPM

 

[Reserector_]

Good point. I needed and excuse to buy a hand-held tach, anyway.

 

[chevymaher]

Something is off. My 3 liter runs 4000 @ 35 mph with a 21 stainless prop. It goes faster but at 35 that is what it does.

 

[Reserector_]

We may have different final drive ratios.

 

[mickyryan]

Shouldnt if it was a original 3.0 if it was a v6 drive or v8 then you would need totally diff prop to compensate but since your rpm are low im betting you are overpropped

 

[Reserector_]

Here's a link to my early prop size figurings. https://forums.iboats.com/threads/bought-this-boat-with-no-prop-where-to-start.727585/

The lower unit is definitely the later (1993) OMC Cobra 3.0 setup that used the same lower unit as the v6. Not the smaller lower unit with the 1" shaft.
I estimated 1.88:1 final drive. Someone in that thread said it was probably the 1.86:1

I looked up the gear sets for this stern drive and the upper has 21:21 gears. The lower has 14:26 gears. That works out to 1.8571428571:1 to be precise.
3,000 rpm divided by 1.86 = 1, 613 revolutions.
1,613 x 19" = 30,647" or 2,554' or 0.48 miles
.48 x 60 minutes = 28.8 mph (that is assuming there is zero prop slippage)
My pito speedo indicated 35 mph. My GPS app said 33.

These same calculations with a 17" pitch would give me 25.96 mph. We just hope the rpms will reach 4,000 or more. 4,000 would (theoretically) give me 34.63 mph. That is 5.8 mph faster than my current theoretical speed.

What does all this mean? It means I cross Lake Bogue Homa in no time at all and have to pay attention not to run ashore. LOL

I already have a 17P I can throw on it next time I take it out. I found great deals on both used props and figured I can always use one or the other as a spare, so that's how I justified buying more that one to start with.

 

[Reserector_]

Problem with using ink or a marker on foam is that it can bleed thru especially with white vinyl. May take a year though.

Marking on the back side of the vinyl is even worse.

By the way, thank you again for pointing this out. There were some places on those first pieces that I marked with blue sharpie that eventually bled through. They don't bother me, because it was part of my journey, but that woud've been everywhere had you not warned me.

 

[sopwithcamel74]

That was a heck of a ride of a build to follow. The scope of your abilities and your drive to make your ideas come to fruition are astounding; well deserved Splash of the Year title, champ. And she's an absolute beaut of a build, to boot.

 

[Reserector_]

That was a heck of a ride of a build to follow. The scope of your abilities and your drive to make your ideas come to fruition are astounding; well deserved Splash of the Year title, champ. And she's an absolute beaut of a build, to boot.

I'm pretty sure I blushed when I read this. Thank you for that.
Stay tuned... I will be repairing a crack in the block next. I plan to use the Lock-n Stitch method. Should be fun.

 

[Scott06]

I'm pretty sure I blushed when I read this. Thank you for that.
Stay tuned... I will be repairing a crack in the block next. I plan to use the Lock-n Stitch method. Should be fun.

I am interested to see how this lock and stich works out! I think with the manifold removed you can access it fairly well no?

 

[Reserector_]

I am interested to see how this lock and stich works out! I think with the manifold removed you can access it fairly well no?

Exactly. Direct access with no disassembly other than the manifold.

 

[Reserector_]

Just a quick update; My next act was to repair the crack in the side of the engine block before I start using it this spring. Well...that hasn't happened yet.
The boat project kept me occupied for two years while I let some other chores and household repairs fall behind. I expected to have allot of that caught up before moving back the boat project, but I still have not gotten caught up.
NOW we are into Oppressive Heat Season, so there is no telling when I will get around to the crack repair, but I may have to run it like it is or syphon the gas. In the back of my mind I know there is ethanol gas in that aluminum tank that needs to get gone.
So that's where I'm at with it.
My wife and I are tied down with caring for her mother around the clock, so allot of things are on hold at the moment. Just need to keep the equipment maintained for now.

 

[kcassells]

Just a quick update; My next act was to repair the crack in the side of the engine block before I start using it this spring. Well...that hasn't happened yet.
The boat project kept me occupied for two years while I let some other chores and household repairs fall behind. I expected to have allot of that caught up before moving back the boat project, but I still have not gotten caught up.
NOW we are into Oppressive Heat Season, so there is no telling when I will get around to the crack repair, but I may have to run it like it is or syphon the gas. In the back of my mind I know there is ethanol gas in that aluminum tank that needs to get gone.
So that's where I'm at with it.
My wife and I are tied down with caring for her mother around the clock, so allot of things are on hold at the moment. Just need to keep the equipment maintained for now.

Yup life things always have a way of taking priority. Family first.

 

[Scott Danforth]

Take boat out, run it

Or siphon the gas and run in the lawnmower

 

[Reserector_]

If it WAS ready to run, it's too dang hot to enjoy it right now. Mid to upper 90s and 100s. I'll plan on September repair and then enjoy some fall rides.

 

[chevymaher]

Good thinkin.

 

[Reserector_]

So frustrated. It's been mid-90s for weeks now, with the heat index usually around 100°. I cannot work in that, nor can I enjoy boating in that.

I HAVE been commuting on a motorcycle and it's been rough, but at least I can keep moving through the air.

By the time I get back to boating, it will be time to start SOTY nominations. :-/