new motor for a 283 convincor

[tcob]

zt help me out here .what do you think i'm looking to gain speedwise , going from the 500 (low 70's speedo ) to approx 630 hp ? and on a sour note did you know a guy , byron , on lake george . all white 29 profile ,built hp500... he also had a smaller older checkmate outboard ? he was tight with jason ......

 

[Dave's ZT260]

I would expect 8mph gain. Definitely less than 10mph. So you will be at 80mph give or take. You will need hydraulic steering at that speed. I've already been there and the chine walk will be uncontrollable.

Who is doing the motor for you?

I know of Byron’s cat. Didn't know him personally. Crap, did something happen?

 

[tcob]

thanx 8mph would be fine . jack boyd from mayfield , he also does jason's machine work as well as jimmy denooyer's , so good enough for me .merlin block , air flow research aluminum heads etc , waiting for a "warmer" day to dyno it . byron . we got the same guy ????? 29 profile "deep v" hull no cat .... died from snowmobile accident a few weeks ago.

 

[Dave's ZT260]

The guy I was thinking of has a white cat with an blown HP500 runs 100mhp. I might be confusing the guy. A shame either way.

Jack Boyd has a good rep, what did he say about the bravo drive holding up? And the streering?

 

[tcob]

he mentioned a few more "locals" with more power than me , that are running bravos w/o problems . they are using care .....myself i'm up there several days a week , prefer not to run sunday afternoons when lake is crazy no need to beat boat or my body . you guys have raised enough doubt in my mind though , and i will probably buy something , once i've settled in on what will "work best for me". am exploring all options . thanx again. RISENSHINE !!!!!

 

[Dave's ZT260]

The drive will not hurt you, just your wallet.
The steering can kill you!

Be careful.....

 

[vinny p.]

Boats are just like race cars, there is no sense in having 1000 h.p. if you can't get it to the ground.

 

[tcob]

vinny , i'm not doubting anything you guys are saying . i replaced the motor first because it broke first . i would have been happy with the 500 and a fat wallet . i am beating the bushes in my spare time. my wrench is also looking into it for me through his mercury rep for their opinion . so far i have found that mercury figures 600 hp is about max for that drive , but they do offer a ton of stronger replacement parts for the bravo .steering ... no argument , at all , can probably do that by early summer , saftey is not an option . but i gotta spread this out a little .....i have a question for ya , is the steering only to prevent chine walking ? if so , its going to take a lot more than 600 hp to make this baby dance ! thanx . RISENSHINE !!!!!

 

[Dave T]

Bob, the hyrdraulic steering is much stronger and more stable then the steering system you have now. The stock steering won't handle as much torque from the drive and if the steering arm breaks the drive will turn and send the boat and you for a ride.I have A 98 251 with purple and black .How is Jack boyd to deal with?Im looking for A set of cly heads for 502 im building for my 25.
Dave

[This message was edited by Dave T on March 24, 2004 at 06:35 PM.]

 

[vinny p.]

Bob,
Hydraulic steering not only makes the steering more responsive, it helps to eliminate unneccesary strain put on the gimbal. It does this by transferring the load of steering to the drive rather than the gimbal ring. The dual piston set-up will stabilize the drive during high speeds and turning. It is the only way to go.
From what I understand, the best advice is NOT to waist money on performance parts for your Bravo 1. Save your money until you can get an XR or an Imco. The aftermarket replacement parts for a Bravo are not much better than the stock parts. The problem is that they are just not big enough. The XR or Imco allows for bigger shafts, bearings, better tower and straight cut gears.
As always, there are several ways to drive your boat. I am sure that with the power you are looking to upgrade to, you can run the boat within reason and still not blow the drive up. There are alot of guys out there running some pretty big horsepower numbers through stock Bravos and living to run another day. BUT, the fact is that you will have a drive failure. It is just a question of when. Alot to do with when has to do with your driving habits. I am sure you know the deal with holeshots and jumping waves. There are also a few hidden factors that some people may not realize. The size of your prop and weight of the boat have alot to do with the life expectancy of your drive. The bigger the prop, the more weight of teh boat, the more the strain will be on the drives shafts, gears and tower. My 259 will put a considerable amount less strain on a drive than will your 280.

 

[tcob]

hey dave , i'm going to upgrade the steering as quickly as possible . i've been docked at edinburg marina since 1977 ! we would love to meet more checkmate owners . i've been out of the hot rod loop so to speak for the last several years but iguess i'm comming back with a vengence . jack boyd , he's the best , country boy !talented and honest . i left it up to him 100 % . just told him to impress me . your 251 should respond nicely to mods. i had an 88 . that hull was amazing . i see it up there some times , white , with a little maroon stripe . oh and jack does have some used parts and usually knows what else is around.RISENSHINE!!!!!!

 

[tcob]

vinny.....i'm getting an education FAST . i appreciate your time in getting me up to speed ,,RISENSHINE!!!!!!

 

[Dave T]

Bob,
I think I know your old boat .It belongs to A guy I know.1988 with A 454 mag with two deck hatches?Boyd just built A small block for my fatherin law for his 55 chevy.My father in law was very happy with him.I have been waiting on performance marine for heads for the 502 for 4 months.

 

[tcob]

dave i loved that boat . different animal from the 283 . i beleive we are talking about the same boat . guy is very easy on it . does yours have the flotation boxes in the engine compartment ? i removed them from that one after checking with checkmate . it ran 77 with a diferent motor in it . i was told that checkmate put a slight hook in when they reintroduced it as the convincor classic . you know anything about that ?it would be a shame . that hull had a lot of potential , narrow beam ! RISENSHINE !!!!!

 

[tcob]

DAVE , i was surprised how long it took for all the engine parts to come together .it was months also for my heads . they are beautiful though ,must be a lot of guys with a need for speed . jack is proud as hell of what he's turning out , and did i mention a 1 year guarantee ? so what you buildin anyway ? RISENSHINE !!!!!!

 

[Dave T]

I have the short block all done .It it simular to A hp 500.I was just going to use A set of stock retanular port heads with some good parts but I cant wait to much longer for P Marine.Im thinking of going with the AFR as cast heads(305cc) I think.
Dave

 

[Dave T]

Bob,
I stopped up to se Boyd friday to get A price on heads.I saw your engine on the dyno .He said he was going to run it later in the day.How did you make out?
Dave

 

[tcob]

hey dave , last i heard was 647 hp and 666 torque and still climbing . running out of carburator . stay tuned ! did you locate heads and will you be up and running for the start of season ? RISENSHINE !!!!!

 

[Dave T]

Bob,
That 28 will be flying this year!Jason said the heads will be done this weekend.Our boat is ready to go.The boat has A 310efi 454 in it now .The 502 is A project I have been working off and on for A couple of years now.
Dave

 

[tcob]

dave . cool on the heads . hope you're right on the 28 . now , i gotta find more gold for an outdrive and steering . ohhhh , these projects !! RISENSHINE !!!