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Hull #18-83
05-03-2002, 02:12 PM
Hey Donzi speed freaks, need your advice on trim. I have always read and heard that the old classic hulls don't benefit from a lot of positive trim on the outdrive. In viewing some of the photos on this site, some of you are carrying the bows of your boats high out of the water. Your thoughts please on how much trim is enough for max speed. My 1966 18' barrleback is fit with a Volvo 270T. Engine is a stroked SBC that dyno'ed at 400 HP. The boat feels like it is riding way too wet, increasing drag and reducing speed. Maybe I need a prop with more bow lift. Ideas?

BigGrizzly
05-03-2002, 03:42 PM
I would put the pin in the middle holw ans run a Hill propeller with 23-24 pitch oe a 24 Ultra if you couls fins one. The only other option is that Solas male props with Volvo hubs. You can run the pin in the outer hole but it will not cruise well.
Thoes things you read were incorrect. That same sorse said never use a rocker hull.

Randy

Greg
05-03-2002, 06:04 PM
Welcome the site Hull# 18-83. I am in the process of redoing my '66 18, Hull #92. Mine is also dated around the end of Sept. for that year. Is there a date in yours? Is the motor cover a single hatch or a triple? Mine is a single. I can't help with the trim problem as mine had an old Volvo 200 on it. I ran mine in the middle hole. I was using a Michigan Wheel bronze prop. When I put it in the outer one it didn't handle well at all.Boy, they quit making those drive units for a reason. I have to say it held up well under many a severe beating.

GEOO
05-03-2002, 07:21 PM
The higher you trim the faster you will go at WOT. Won't be much fun at slow speeds. You'll be bouncing all around. GEOO

Forrest
05-06-2002, 08:00 AM
270"T" - has power trim. He don't need no stinkin' pin!!!

BigGrizzly
05-06-2002, 08:47 PM
I missed the "T" part sorry.

Randy

Hull #18-83
05-07-2002, 12:15 PM
Like Forrest said, I installed the 270T o/d on boat. It has hydraulic trim but seems to have little effect on the attitude of boat at speed. Could be that the trim seems to work much slower than Bravo trim. Next time out, I'll just hold the trim button longer and see what happens!

My 1966 is a triple engine hatch model. Build date was 7-16-66 per black writing under deck.
At present, I am running a 14.5 X 24 L/H 3 blade SS prop built for me by Joel at Bronson Propellers. Anyone had any experience with this prop?

Forrest
05-08-2002, 08:29 AM
That's the prop Grizz' is runnin' on his 18 Corsican, but he will have to tell you what pitch. I just picked up a left- and right-hand pair of 15 x 27" Hill Volvo props that I plan to try on my Magnum soon. Prior to getting the Hill props I ran 14.5 x 24 Volvo Ultra props. Now since the new 383s came along, this pair of engines would turn more than 5600 RPM with the Ultras and the 1.61:1 gears in the 280Ts. I would like these engines to run in the 4700 to 5000 RPM range.

Hull #18-83
05-08-2002, 10:25 AM
Forrest, I will be interested to hear your thoughts on the Hill Volvo props vs the Volvo Ultras? More or less bow lift, etc. Thanks!