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View Full Version : 22' Classic w/ OMC 454 King Cobra Drive



MooresDonzi
02-13-2015, 12:13 PM
Hi, Looking for any recommendations for upgrading current prop for my 1992 22' Donzi Classic - as listed on the title - it has the OMC 454 (not HO) matched to the OMC King Cobra drive - current prop is a stainless steel 4 blade with NO MARKINGS so I don't have a reference point to start from.....Boat runs 57 on gps turning 4800 rpm - looking to see if there are other props that might squeeze out a bit more speed without sacrificing overall performance
Thanks in advance for any feedback!

Pat McPherson
02-13-2015, 01:55 PM
I have Bravo so hopefully some of the guys with Cobra drives will chime in. I'd try a Turbo 1 or Merc Mirage in a 23p...

gcarter
02-13-2015, 02:11 PM
I believe w/320 HP, that's about all you can get......maybe 60 on a good day.
You might want to start looking for another engine. If it's the hump back KC drive, it a good drive,
so I wouldn't plan on a change there. Some here can fill in all the other details, but w/another
100-125 HP, you can top 70 pretty easily. But you'll need a different engine, your engine can't be
brought up to those numbers easily.

smokediver
02-13-2015, 02:45 PM
Your drive should be a 1.43 not a 1.5 like most bravo drives on classics. I don't think you would be able to turn a 23 unless it is labbed. Raker is a good omc bow lifting prop and I believe can be had in even pitch numbers. A 22 raker might be a good choice for you. It's a 3 blade prop

BUIZILLA
02-13-2015, 02:55 PM
57@4800 is what mine ran with the same power... I would leave it alone

joseph m. hahnl
02-13-2015, 11:20 PM
If you bring it to a prop shop they can measure the pitch. Then you'd know what your working with. I think those 454s were small duration flat tappet camshafts. A set of 1.6 steel stamped rockers on the intake might give you a little more peak HP and rpm. Depending on the lobe lift, modification to the push rod clearance hole maybe required. scroll through this to see if there some stats with your engine and drive package http://www.donzi.net/forums/showthread.php?33017-HOT-DONZI-S

BUIZILLA
02-14-2015, 07:07 AM
I think those 454s were small duration flat tappet camshafts. A set of 1.6 steel stamped rockers on the intake might give you a little more peak HP and rpm. Depending on the lobe lift, modification to the push rod clearance hole maybe required. scroll through this to see if there some stats with your engine and drive package http://www.donzi.net/forums/showthread.php?33017-HOT-DONZI-S this isn't a small block application that came with 1.5's... this came with stamped and probably non-adjustable 1.7's.... if it's the 310hp it will need cam, heads, and jetting to wake up, if it's the 340hp it needs a cam and jetting as minimum

also, the prop markings may be under the rear washer at the hub inner area if it's an OMC prop, that's where mine was, I had either a 22 Raker or a Viper to start, can't remember the model, but i'm positive on the size.

hope this info helps

MooresDonzi
02-16-2015, 12:35 AM
Hey Gang,
Thanks for the prompt feedback! I had a 96' 22' Classic that had a Merc 502 EFI and Bravo 1 which rian AWESOME spinning a Bravo 26 Stainless 4 blade and GPS's at 73 mph at 4800 rpm. Regrettably I had to sell it!!! Having sellers remorse I searched for another one, but could not find one with the same set-up without spending lots O money LOL!

I think I'll just keep it 'as-is' and just enjoy it! I'm in California and not many Classics out here - Thanks again for the information!

joseph m. hahnl
02-17-2015, 07:04 PM
this isn't a small block application that came with 1.5's... this came with stamped and probably non-adjustable 1.7's.... if it's the 310hp it will need cam, heads, and jetting to wake up, if it's the 340hp it needs a cam and jetting as minimum

also, the prop markings may be under the rear washer at the hub inner area if it's an OMC prop, that's where mine was, I had either a 22 Raker or a Viper to start, can't remember the model, but i'm positive on the size.

hope this info helps Them dang big blocks are just bigger in every way:kingme:

Barry Eller
03-03-2015, 01:57 PM
My 1993 Donzi 22 Classic came with the 454HO, King Cobra Cone Clutch Drive and a 21" 3 blade OMC Viper prop. The exhaust had been changed to EMI's and it's speeds were in the low to mid 60's. I have a 502 now built to be a HP 500 clone...speeds in mid 70's with 25" Turbo 3 blade.

miike
03-13-2015, 06:21 AM
Mine ran best with a 23 mirage

Did 64 with thru hull exhaust.

Change drive oil every year and reveal drive if you find water.