31 awesome OB conversion
 

Hey folks

Picked up a 31 awesome hull and trailer locally for a decent deal. Currently i/o. Considering converting to twin outboards. Would like to see 75 mph. Nothing crazy. My options are to put it back with 454 mags and bravos or outboards on jackplates.

Ive read so.e guys were only seeing 70 mph with trip 300x....tgis sounds ridiculous to me because tbe old chris cats and shadows ran 100+ with trip 2.4s...

Whats the deal?

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Good idea thanks man!

I have a friend w/a 33' Warlock that has everything from twin turbines to twin O/Bs.
W/twin Merc 300 2 stroke O/B's it ran mid 70's.
It now has twin 225 or 250's and runs high 60's.

33 warlock cat with outboards? ? That's cool! Got any pics? Warlock is a cool hull. I had a 25 sxt cat. Fun lil boat.

The vrods on my 31 are 325 each...I'm shooting for 75.

lol sounds lie,my kinda guy!! Id,love to see it#

I have a 97 31' Awesome Cat rigged with triple Mercury Pro Max 300X. I can easily cruise at 75-80 and top speed has hit 105 (not by me). My best was 98 but certainly does not struggle to get past 70.
Just saying.

Dude that sounds badass!!! I'd love to see some pics!

Mine is ready to fire up and sea trial. Just gotta get back home from work so I can mess with it

so what engine recipe did you end up using?

Hey man!

I went with 325 whipple tuned verdos on 8 inch jack plates. 13 inch setback total. Swapped out the 1.85 big bullet hd lowers for 1.75 dwp TM lowers. 1.25 prop shafts.

Finally got around to firing the engines. Both run. Gotta tidy up some wiring and bleed the steering and throw some props on it

Progress ... engines are running. All functions are tested and operational. Had a lil gremlin that took some time to figure out. Had the wrong series dts command modules in my helm harness and was causing some funky stuff. Got 28 bravos on it to start .hope to dunk it this week. Been too busy testing props on my other boat lately . But she's there

Any updates? Also can you take a closer side shot? are you able to trim the motors up?

ddv005:

New to this forum...trying to figure out how to post pics. All 3 motors can be trimmed simutaneously or port and starboard engines can be trimmed individually

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Tuxy , I actually joined back in 2008 but don't post much. Thank you for your response to my question thought. Is your boats transom like the one pictured here? or is the transom
notched to accommodate the OB motors? Could you please post a pic? Thank You

Hey man! My engines are on jackplates...the transom is not notched. It's flat. I can easilyhttps://cimg9.ibsrv.net/gimg/www.off...6e85630356.jpg
trim the engines just past 45 degrees from vertical. More than enough to suit me since No trim is required to trailer /load/unloed the boat.

Ok, so after nearly 2 months of waiting on the Merc guy to reprogram my modules (litealite 10 minutes of time 🙄) all the right hardware is now in place. All functions are operating as they should. Only thing needed is to reverse the polarity on the starboard shift actuator so the lower unit goes in forward when the lever is in forward. Vrods have opposite shift shaft rotation from the TM lowers I'm using and the actuators shift in the same direction for both standard and counter lowers on vrods. The reversing of the dog clutch is don't internally.

I've basically been waiting all summer on this guy with the laptop. And he really isn't very good because I had to figure out what was wrong every time we tuned it...It's what I get for living in the middle of no where .lol

Hang in there 2ton your in site of the finish line! We are rootin for ya.

Lol thanks man!!! It's close!!! 😎

Chris cat conversion
 

2Ton

Thanks for your reply. i am doing a similar conversion on a Chris cat and was debating whether to cut out transom or not. I am very much looking forward to
see how your boat performs as i am considering same exact power.

Tuxy

I just realized you have same boat as 2 ton with trips on a Jack Plates? What setback on the jack plates?

Right in man! Post pics! Love to see it!

just keep in mind that verado motors have an additional 5 or so inches of setback built into the bracket. So along with the 8 inch jack plates I'm using it has basically the same measurements as 13 inches. I put my jack plates low enough on the transom that i can run 20 or 25 inch motors. The boat should run 80+ with right setup ....but anything over 74-75 and I'm happy. I was just going for 75 mphm ph, dependability, low fuel burn, big cuddy, great rough water capability and low noise.

I think this will for that bill nicely.

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CC30 Project
 

As you can see mine needs ALOT of work. Had to rip out all of the rot first and then a bit more for safety. Filled with two sheets of marine plywood and secured with ARJAY/ cloth and resin. Tomorrow (weather permitting) im going to finish glassing the transom and then
i will move on to the bulkhead(wall behind back seats) and then finally the stringer. I am anxious to see how your boat performs with the Verados. Please let us know once you have had a chance to run her .

Looking good! Getting started is half the battle!

Did first sea trial few days ago. Super smooth. All all systems working well except for a bad connection on the starboard trim actuator. Easy fix but made trimming nearly lol

72 mph at 4950 rpm. Neutral trim. 28 bravos spinning in. 6% slip. Propshafts were nearly 3 inches UNDER the bottom. 100 gallons of fuel. 600 lb load. Starts porpoise at about 65...seemed like it tarted to settle at about 72 ...that's as far as I pushed it.

Propshafts been raised 3.5 inches now at .5 inches Above the bottom. This should make a drastic difference in performance and handling. Possible up to 10 mph according to comparison. But will see what happens next time out . Also not sure the bravos are my best option...going to try some hydtomotives and some outboard over hub choppers and cleavers .

First sea trial
 

WOW!!!!!!!

For 1st time out those are amazing results, based on those numbers i don't see why you wouldn't hit 85 mph !!! With my verados i know they rev til at least 6200 so you have at least 1000 RPM left on the engines. Also
you need to be able to play with the trim, i can tell you on my other boat (i know V bottom is a different animal ) 313 Chris Craft Stinger Twin Verado 300 outboards, it LOVES trim. The engine height is crucial as well, i got lucky on my
313 that height was perfect first time out. That boat does 69-70 mph with a T-Top, 150 gallons of fuel, 4 people. I have a feeling that once you sort it out, she is
gonna be at least 10 -15 mph faster. Thanks for your post, gives me great hopes !!!!!

Thread back from the dead lol

so testing after raising the engines yielded virtually no improvement to speak of other than handling. (Much better I all aspects) and a slight blowout while tipping over onto plabe. But...i figured out that my engines are only 275hp. So I've just got too much prop for them as they are. The 28 bravo io props will be an ok all around prop once i send ecms off this spring and do 345 tune from Whipple. Should get the boat to 85-90 mph without much problem. I've got some 30p cleavers and 28 lightning ets and some 29p mirage plus props to play with also.

If the 28 ET's don't work out for you and you want to sell them I would be interested
Kirk

Ok. They are 3 blade. In perfect shape.

I'll be testing again in a month or two. Got alotgoin on

Kvogt..your messages are full.

Hell yea! Nice! How fast?
any pics ?
Any advice on setup?
What props have you tried?

What's your best all around x dimension?

My number is 813 482 1656

Have you been able to do anymore testing?

Havnt as of yet.... Weather, work, corona, other projects etc etc 🙄 hopefully won't be long

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finished new fiberglass hatches yesterday...the old hatch musta weighed 350 lbs lol