Upgrade or NOT?

[kwoolard]

Re: Upgrade or NOT?

OH......I would still go with the 4BBL...



My block was a 1pc rear main seal, roller cam, 2 bolt main w/ a mech fuel pump.....

Give Raul a call.......what did he say about the 383???

Negative on the 383 from Raul.

Other sites like Michigan Motorz list the 383 long block almost $2 grand higher that the 350 vortec, what's the deal with that? The rotating assembly, rods and pistons can't be that much more than the 350

 

[kwoolard]

Re: Upgrade or NOT?

Tony, what carb and intake did you add?

What are your current performance #'s and was this an upgrade from what you had previously?

Our boats are simliar in design and weight...at least for comparison purposes.

 

[FreeBeeTony]

Re: Upgrade or NOT?

I bought my boat with known engine problems........LONNNNNNG story. Never ran right and I finally blew it up......so don't have any "before" numbers

I went with an Al intake/dual plane/highrise (forget where I bought it), I am FWC'd and the Edelbrock 1409 carb (highly recommend).

Performance numbers:

Engine: 355 (350 bored 0.030 over)
Outdrive Ratio: 1.5:1 Alpha
Prop: 17" pitch Al
Weight: 4000lbs (according to GW catalog)

Cruise at 30MPH @ 3600 RPM
WOT: ~38MPH @ 4600RPM

 

[kwoolard]

Re: Upgrade or NOT?

I guess I had a 355 as well.....my pistons are stamped with 0.030. I know the previous owner replaced the motor because it froze and cracked, must have put a reman in.

My current perf. #'s are:

Engine: 355
Outdrive Ratio: 1.47:1 Alpha
Prop: 15" pitch Al Black Max
Weight: 3200 lbs dry, add engine and outdrive 4200 lbs. (according to Sea Pro catalog)

Cruise at 30MPH @ 3400 RPM
WOT: ~39MPH @ 4400RPM

Not sure if the overbore makes that much of a difference. I've thought about going with an Al intake as well but worried about external corrosion from the salt air. I gues I could paint it. I've read that the high rise intakes actually cause lower power and torque at the low rpm range.....don't have any facts to back that up.

 

[FreeBeeTony]

Re: Upgrade or NOT?

Guess our numbers are pretty close..........you're doin a little better than me........

I think the highrise helps the low end torque........just gotta make sure its a dual plane.....I think.

 

[kwoolard]

Re: Upgrade or NOT?

Guess our numbers are pretty close..........you're doind a little better than me........

I think the highrise helps the low end torque........just gotta make sure its a dual plane.....I think.

I take back what I said, I actually read that it reduces throttle response below 4500 rpms. That makes more sense....

 

[Bondo]

Re: Upgrade or NOT?

Not sure if the overbore makes that much of a difference.

Nope,... It Don't....

I've read that the high rise intakes actually cause lower power and torque at the low rpm range.....

Ayuh,... I think you might be confusing Hi-rise,+ Open plenum...

A Dual Plane(Not open plenum) manifold, with a hi-rise isn't a Bad thing...
A Single plane(open plenum) whether hi-rise or Not, won't run for $ht on a boat motor...
They're for Hi-rpm Racin'....

 

[wca_tim]

Re: Upgrade or NOT?

Holy crap man, I just realized where you live...

Do you know where Joey Griffin's shop off 264 between Grimesland and Washington? He's one of the best marine engine builders on the east coast when it comes to performance engines and is a straight shooter. He and his guys do some of the best machine work I've ever seen and are straightforward to work with. definately worth talking to if you don't have some reason not to.

 

[gsrsol84mm]

Re: Upgrade or NOT?

Raul at Rapido Marine will build you a 300-320 HP longblock motor for $1735 Delivered. All you will need is a 4 barrel carb and intake.
After extensive searching, this made the most sense to me .
Additional power over a standard 350, similar to a 350 vortec power for half the money and wont shred your outdrive.

 

[fishingman220]

Re: Upgrade or NOT?

My current perf. #'s are:

Engine: 350
Outdrive Ratio: 1.81:1 Alpha
Prop: 13 1/4x 19 mercury vengence
Weight: 3650, plus motor and gear

Cruise at 30MPH @ 3800 RPM
WOT: ~42MPH @ 5000RPM

mine is a 23ft proline cuddy, i just rebuilt mine this summer, mine is running a 2bbl mercarb, really wish i had the money to switch intake and carb but the motor ate all that money.

 

[FreeBeeTony]

Re: Upgrade or NOT?

My current perf. #'s are:

Engine: 350
Outdrive Ratio: 1.81:1 Alpha
Prop: 13 1/4x 19 mercury vengence
Weight: 3650, plus motor and gear

Cruise at 30MPH @ 3800 RPM
WOT: ~42MPH @ 5000RPM

Just curious as to why you are using a 1.81:1 outdrive?

 

[fishingman220]

Re: Upgrade or NOT?

dont know, it was on the boat when i got it. its the one from the factory, all the numbers in the books when it was new matches up with the drive

 

[fishingman220]

Re: Upgrade or NOT?

it actualy needs a 21p prop, it is alittle hard to get on plane but once you start shoving the tabs down it gets up ok, but i can run the rpms all the way up 52-5300 now and the motor is supposed to be 42-4600 range, so i think it needs to be re proped but it will be alittle hard to get out of the hole.

 

[270win]

Re: Upgrade or NOT?

If there is a concern about the Alpha standing up to the motor, you need to stay under 300hp...yes, torque does kill them, but they have a hp rating for a reason. MerCruiser won't stand behind them above that level because they won't take it unless you baby it continually...personally, that would get old to me. Not to mention I would always be wondering when, not if, the drive is going to give up. Do you go offshore? That's the last thing I'd want to be wondering or worrying about in big water.

If it were mine, I'd either upgrade the drive to a Bravo, or stay with a 300hp motor. The main benefit of the additional torque the 383 will generate will be realized in getting that boat on plane...but if you have to feather the throttle, what's the point? Rapido can send you a roller vortec motor with a cam upgrade. It would have more hp potential than 300, but you can retard the timing to keep it in check. They can also degree the cam to meet your goals.

Also, a 4bbl will typically get better fuel mileage than a 2bbl...as long as you stay out of the secondaries. They generally start to open just above 3000 rpm on a 5.7. But, if fuel economy is a big deal, you need to look at fuel injection...no comparison in economy.

+1 on what Bond-o said about the intakes...

 

[kwoolard]

Re: Upgrade or NOT?

Holy crap man, I just realized where you live...

Do you know where Joey Griffin's shop off 264 between Grimesland and Washington? He's one of the best marine engine builders on the east coast when it comes to performance engines and is a straight shooter. He and his guys do some of the best machine work I've ever seen and are straightforward to work with. definately worth talking to if you don't have some reason not to.

You must live around here as well to know Joey or have you used them in the past? I know Joey, his shop is about 1/4 mile from my hydraulics and machine shop (Mid-Atlantic Hydraulics & Machine)

Joey used to build some performance engines for Fountain Powerboats Racing before they went south. I believe Joey has closed up shop, but I will definitley have him do my machine work if I ever start building on this 350 block I'll have left over.

 

[kwoolard]

Re: Upgrade or NOT?

I've got a chance to pick up a 5.7L (350 ci) Delco Voyager EST Marine Electronic Distributor Kit cheap, would you guys prefer this over the Thunderbolt V or should I stick with the TB V?

 

[Bondo]

Re: Upgrade or NOT?

Ayuh,... The T-Bolt V is about the Best there is,... Why change it,..??

 

[kwoolard]

Re: Upgrade or NOT?

Just asking for opinions..........

Ever since I changed my hall effect sensor in the distributor last year, the last 2 rotor wheels i've installed hit the sensor. Doesn't affect the igniton but you can here it clicking. Anybody ever had that happen, must be the aftermarket sensor I bought. I installed the same one on a friend of mine's boat and his is fine.

 

[wca_tim]

Re: Upgrade or NOT?

You must live around here as well to know Joey or have you used them in the past? I know Joey, his shop is about 1/4 mile from my hydraulics and machine shop (Mid-Atlantic Hydraulics & Machine)

Joey used to build some performance engines for Fountain Powerboats Racing before they went south. I believe Joey has closed up shop, but I will definitley have him do my machine work if I ever start building on this 350 block I'll have left over.

Sure, I recognize the name of your shop from driving by. I live in Greenville and make it up that way fairly often. I'm no expert on all this, but love to play to the extent I can afford to and in the warmer months can often be found screwing around on the Tar or Pamlico...

Joey's guys built the engine that's in my boat now. I had occassion to drop by once or twice while things were coming together and was really impressed with the quality of work. I'd never done a boat engine, but I worked as an auto mechanic years ago and was also formally trained as a machinist some years later. Their work is top notch - and his guys know their stuff.

I've no idea what he's doing with the business, but I was out there a few months ago and they were doing work. I assume that he's not so interested in doing a lot of work these days or perhaps is picking and choosing things that are fun for them to do? I never would have known they even existed if I hadn't asked the right person when I started actively looking for a machine shop in the area.

If it weren't so damn cold this afternoon, I'd probably be on the river playing instead of piddling around at the house... See you on the river...

ps. second the above on the tbolt ignition - great set-up. If you really want to improve on it, add a crane Hi-6M cd ignition box.

 

[fishingman220]

Re: Upgrade or NOT?

some of the guys i have talked to with boat of my size and weight say the very best thing to put on there if your not worried about money is the bravo 3, said its much much better on getting up on plane and can stay there longer at lower speeds, and gets rid of your steering problems at idle