JustSayN20 pkg on it's way

[mattyboy]

Bill
sorry i was called out of town with work so the props be shipped tom. I'll send tracking info once I get it


the cleaver is in great shape and very sharp so it is in a double box the chopper has some minor scuffs on the edge of one of the blades but shouldn't effect performance at all

[Just Say N20]

Matty, that's awesome! Thanks so much.

I have been coordinating with Keith about final assembly of the engine, so I can hopefully just make one trip to his shop, arriving with the engine on the dyno, give him the CMI exhaust, run some break-in/pulls, then cart the whole thing back to Michigan.

It will be interesting for sure.

[mattyboy]

Bill
I'll give you my impressions on each prop you might need a few different size thrust washers


the 26 cleaver I never got it up high enough to the surface where they like to run so i didn't run it that long

I ran the 25 chopper for about a season and i had some pulling issues with it but that was due to the nose cone and some play in the steering.

gloves for the cleaver is a must

[Conquistador_del_mar]

Bill,
I will be curious how they run for you since I have had serious problems with choppers (unbelievable steering torque) and limited success with cleavers. I presume you will be running them on a Volvo drive - correct? Did you try a Titan yet?

[Just Say N20]

Did you try a Titan yet?

Bill,

I will be running them on a Volvo 290 (1.61:1) with trim. I have run the Big Grizz Solas props, both a 19 & 21, but that was with the first rebuilt engine. I never had a dyno pull done on that engine, but I would guess it was around 260 hp. The fastest prop, and best cruise/rpm prop so far, with the old engine was a Volvo Ultra 24". The Ultra took some getting used to; it was a bit more flightly, and even though the prop slip numbers worked out to be around 19.5%, you could trim the drive until the boat was pointing at the stars and the prop was still solidly biting.

The new engine, will be around 450 hp. I know that at 5,000 rpms it ran 57.3 GPS mph. I will start with that prop, and see how many rpms it will spin. Keith is building the engine to max out around 5,800 - 6,000 rpms. I know of a few people that twist the Volvo outdrives in the 6K range, and have done so for years without failure.

Truthfully, if it breaks 70 with that Volvo "watermelon" lower unit, I will be pleased. I really want something that will cruise about 45, around 3,500 rpms. This should have the power to do that, if I can find a 26" prop with about a 12% slip.

I remember riding along in Brad's 1986 22 and being amazed at how it cruised. He had a 454/Alpha with something like a 1.36:1 ratio.

[Conquistador_del_mar]

Yep, I calculated your Ultra slip at 18.8% (close to your number) which is extremely high - I wonder why so high? If you can turn that Ultra at 5800, your speed would be 66.5MPH, but it might be that your slip goes down a little so you might get the upper 60MPH range. You will be getting into the range where a nose cone might come into play. Please let me know what you end up with after changing the props. I will be trying a Titan 23P LH on my 18' Donzi with the 330HP and hope for around 60MPH. Mine now has a conventional lower foot with the 1.61 gears. My 23' Donzi fishing boat with the 250HP Merc outboard only has a GPS slip of 12% which is as high as any of my boats so I am wondering why your slip is so high. Bill

[mattyboy]

My ultras ran at about 16% slip and ventilated like hell in rough water

These two props ran close but a little higher rpm 100-150 rpm than an early grizz 23 on my 310 HP 351w never tried the newer ones. The early ones acted 1.5-2 inches in pitch higher
Will be interesting to see what a difference 150+ HP and trim make
I like projects

[mattyboy]

a little more info as best as i recall it was a few years ago the 23 solas i could turn to just about 4400 the cleaver maybe the same and the chopper around 4500 once i tried one of the first 21 solas i stopped it got me to 60 on a daily basis at around 4950-5000 rpm it was the best all around prop for any conditions and handled very well.

Kenny has an early solas 21 and a new 23 on the 20 cig they perform about the same that is a heavy boat and at about 5100 rpm with the 21 just gets to 60 that's about the same motor as your's Con del mar so you target numbers should be very close with a 23 on an 18. again these numbers were on a 250 with a nose cone on my 16 and a 270 without a cone on the 20 cig both no trim . you guys both have trim. Grizz always said the like trim even more I have never tried them on a volvo with trim. Grizz's corsican ran very well on a 23 and a 290 with trim not sure what kind of power his 351c put out.

some how i am feeling rebuilding a 250 hp 302 is going to leave me wanting a little more.

[MDonziM]

I ran a 27" chopper when that motor was new and it would turn 5000 rpm. There were not as many prop choises then so I have no idea about a cleaver. The chopper would have a ton of torque steer, and I did have a nose cone also.

The new motor sounds exciting Bill, can't wait to see some pics.

- Marshall

[Just Say N20]

The nose cone issue has been raised.

The outdrive is stripped and ready for some paint, well almost. Anyway, while sanding it down, I did run across some remnants of bonding material, and a couple of the water inlet grooves in the front of the outdrive. I'm not using them, as I added a transom water pickup.

I'm wondering if I should invest in a nose cone. My previous boating experience suggests it would be worth it, if I am hoping to be in the high 60's/low 70's. But in the back of my mind, I seem to remember some negative comments about the steering when a nose cone was added.

Thoughts?

[maddad]

Just say 406, with the 1.6 ratio Volvo, 3500rpm and a 23" Solas goes just under 48mph. That is not even in the secondaries with my mechanical 750 Holley.
http://www.donzi.net/forums/showthre...rop&highlight=
I had a hydromotive nosecone on my 280 leg and at first liked the way it handled. As I got used to driving faster, the boat got twitchy in the back at upper speeds. After I took the nosecone off, the back of the boat settled down again. I'm going to try it again, but only after the external steering is on.
If your motor makes 450hp, you'll be able to turn the 23" Solas to at least 5500. Mine makes 441hp at 5500 and thats the highest I've gone with the handeling issues that come from steering an old Volvo from inside the boat.

[Pismo]

I would love to try an old 27" cleaver on my 22....

[mattyboy]

If I had one I'd bring it up in June. the only prop left is a modified chopper with holes drilled in it and i am not sure what it is for it doesn't fit on a volvo maybe an e drive prop?

[MDonziM]

I would try props before adding a nose cone just to get a clear baseline. Nose cones in general can have pros and cons but my experience with a volvo was so long ago I'm sure someone else has better data.

[Just Say N20]

and if your nice

If. . . . .


Marshall, I think your suggestion makes sense. I like to change one thing at a time, so I know what effect it is having.