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View Full Version : lower chine length older 2+3's



Ralph Savarese
08-29-2000, 08:23 AM
Het guys , does any one know why after 66-68 2+3's they dont send the lower chine to the back of the boat .I noticed that mine is one of few that go to the back?

RickR
08-29-2000, 10:37 AM
Ralph
Are you talking about the strakes?
On most deep Vs the inside strake ends slightly behind the COG. That would make for a softer reentry and less stern lift.
Mabe the strakes changed with the advent of power trim.

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RICKR
mailto:riggerb@aol.comriggerb@aol.com</A>

AVickers
08-29-2000, 12:08 PM
My '76 doesn't have power trim and I don't think it was generally available until the early 80s.

As for the strakes, mine end forward of the stern -- perhaps right behind the COG...

Wasn't there a time in the mid- to late-60s that Donzis were changed from a sharp V to a more rounded V at the stern? Perhaps that's when they changed the strakes as well.

Ralph Savarese
08-29-2000, 12:44 PM
It seems that the lower strakes or chines what ever they are called ends at the beginning of the engine compartment on the newer ones . I was wondering if this would cause more drag on the older ones ? This seems to be the part that remains in the water the most . how much does it effect performance?

[This message has been edited by Ralph Savarese (edited 08-29-2000).]

RickR
08-29-2000, 02:15 PM
You would get more stern lift so the extra drag caused by the strakes might be offset by less wetted hull surface.

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RICKR
mailto:riggerb@aol.comriggerb@aol.com</A>

PaulO
08-29-2000, 02:19 PM
It has been opined on this site that the more rounded bottom on the later classics was to boost speed. As far as the strakes, ones like yours that go all the way to the stern may produce more stern lift. Is that good or bad? I don't know. Let's here from the owners of the early hulls ( GeneD are you listening?) and get some opinions. BTW, the sharper V probably produces smoother landings.
PaulO

BigGrizzly
08-29-2000, 09:28 PM
If my memory serves me correctly the last of the sharp V (ala GeneD)to the saucer bottom was 67/68 this was on the 18 clasics, My 1966 16 was a round bottom. When visiting the factory in Hollywood Fl.I asked that question - the guy said its smoother and faster. i then said "why" he wouldn't answer, he said "look a the 16 the best riding and handling damn little boat in the world". That ended that.

Emmo
08-30-2000, 12:19 AM
My '70 18 2+3 is the deep V transom (last year that I know of) which also seems to coincide with the "barrel back"

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Emmo mailto:emmette@emmette.comemmette@emmette.com</A>

Blewbyu
08-30-2000, 01:40 AM
For long time-I didn't understand the term "barrelback" as applied to a Donzi.Then just recently-I saw the "89" that was really an earlier boat with 89 engine.The white/teal 18 footer in boattrader.
That is one killer looking boat!!!Gorgeous-the stark simplicity is ELEGANT!It is sweet the way the rubrail separates the deck from the hull at the top of the "barrel" crown, instead of 1/4 of the way down with a straight line!!Very,very nice.

Scott Pearson
08-30-2000, 06:52 AM
My 1968 "Barrelback" Does have the very sharp "V". I looked at a 1970 a few months ago and it did not have the sharp "V". Maybe it was a late 1970 I dont know.

(NJ) Scott

GeneD
08-30-2000, 07:09 AM
Hey, I did this 'matrix' last year. I lost it...but I do remember the results - somewhat.
I have to restrict my findings to the 18's, simply because I don't remember what the 16's were.
The cutoff for the sharp "V" to the transom was 1969-1970. More than likely it happened in 1970 sometime.
The reason, already stated above, was to make the hull "looser" to get it to go faster.
The rounded transom also seems to make the boat more prone to chine walking in very fast boats. Reason being, there is no flat surface for the boat to ride on, no pad. It works!
Boats like the pre-70's models, are more stable at all speeds, but let's face it, less wetted surface means more speed.
The physics of hydrodynamics you know.
I wouldn't know about much else on this since my Donzi is the only one I have ever had the chance to drive. Driven in a few, but mine is the only one I have ever piloted.
Forrest says that 007 is the smoothest riding 18 he has ever driven. But that was before he got the X-18 operational.
So perhaps there is something to this full length strake/chine thing.


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GeneD
007
Melbourne, Florida