MOTOR MODS

[TixyB]

Does anyine know what kind of motor mods I can do to a GM 5.7 Vortec with 340 HP? I new to the boating scene, and I want to get all I can out of the motor. Also where can I get these mods? What are the standard mods for a boat motor. (like intake, exhaust, chip, electronic ignitions, coils, etc.) Thank you in advance.

[condor86]

Well i am not a motor guy per se, but i may know the answer to your question. I really havent seen much by way of modifications for marine engines. And i cant tell you why either. The guys at Marine Power might be able to help with this....

I do think that the 5.7 Marine Power engine is already tweaked pretty good to squeeze out 340hp.

[Lucky 275]

In every thread I've ever read about modding an engine, the concensus always falls back to getting a different prop. The increase in HP doesn't seem to make much difference.

That being said, I don't know anything about mods. But I did stay at a Holiday Inn Express last night.

[Wake Havasu]

Re: MOTOR MODS

Originally posted by TixyB
Does anyine know what kind of motor mods I can do to a GM 5.7 Vortec with 340 HP? I new to the boating scene, and I want to get all I can out of the motor. Also where can I get these mods? What are the standard mods for a boat motor. (like intake, exhaust, chip, electronic ignitions, coils, etc.) Thank you in advance.

Dont do it!

They only area to safely play with is the prop.

Do some homework and find out your various RPMs and true speeds then contact Acme prop.

For non wakeboarding you can obatin a little top end speed.

It comes at the expense of low end grunt.

[talltigeguy]

I am not a motor guy either, but I do read some of the discussion boards a lot. I virtually NEVER hear of anyone modifying the engine to get more power. I can't explain well why that is, but it just seems taboo. Some of those same guys go on and on about what they have done to their trucks to boost the power, but seem very reluctant to do it to the boat.

[raythompson]

Engine Mods

I suspect it is more a matter of being practical. To up a 340 HP engine to say 380 HP will not get you much in a boat except shortened engine life. An engine in a vehicle is never really stressed and is not under a constant heavy load. A boat engine is almost always under a heavy load and the engine is already stressed. To take the engine beyond it's design parameters in a heavy load environment will surely lead to early engine failure.

Then you have the problems of additional cooling, expense of add-ons, and yes even safety. Get stranded because you souped up Dodge broke is merely an inconvienence. Break your boat and you are in for a ruined day.

[anhaney]

don't mess with the engines

I have a lot of experiance with engines Drag Racing cars and Boats. The boating world of engines is much diffrent than the car world. Engines in boats are tweeked as much as they can to do a sertain job. They put in computer chips that are hotter and already modifiyed. the compression ratios are higher, the Cam Shafts are bigger, the cooling systems are designed diffrent and all of this is built around COAST GUAURD regulations. They are tweeked as much as possible so you get the longest life and best performance. DON'T MESS WITH THE ENGINES. PLAY WITH THE PROPING. I have used my boat 1 time since I bought it in December but I have already bought three diffrent props for diffrent uses. ACME can set you up pretty good. They have a bunch of NAVY guys to direct you there and they do a great job. Have fun

[CessnaCaptain]

There Are Options.

My dealer is offering a Hot Motor that was modified by Marine Power. I am on the fence between the hot 350ci/340hp??? & the 380HP, vs the 375 PCM. Anyone with any advice or experiences with these it would be appreciated.

My utilization with be both high and medium altitude applications with 1200+- ballast and 7-8 persons on the 24ve for wakeboarding, tubing, ?????<, and slalom recreation,

Thanks in advance,

Cess.

[Andrew]

CessnaCaptian

I would go with the hot 5.7 we had them in the 24ve that pulled the US Open and they were great everyone could not beleive that they were a 5.7. I think the upgrade cost is less than the 6.0 but I think you would be happy with the Hot motor for your boating needs. If this were my boat that is the engine I would go with. I recommend them to everyone. Can't say enough about it.

My .02

Andrew

[wrangler]

Andrew...I may have this confused...but is there an option on the 5.7 litre Marine Power motor that takes it from 340 to 380 hp? I have the 340 version in our new 24Ve. Thanks...wrangler

[CessnaCaptain]

SORRY ABOUT THE CONFUSION

No Wrangler, the 340 is the 340/5.7 and can come from the factory with a few options that enhance performance and the enhanced version is being called the "Hot Motor". The 380 is the 6.0 liter. I would just like to hear from some fellow boaters about their experiences and opinions so I can decide which is for me.

I would hate to make a mistake on such a big purchase.

[TixyB]

anhaney

Thank you for your input. It was very helpful.

The boat is already quick, but you know I am only a man and the urge to max out the performance capabilities is only second nature if you know what I mean.
Looks like the prop is where I stand with the upgrade. I guess I’m going to have to switch my "motor mod" fund to the have the "biggest and loudest stereo on the water" fund.

[Andrew]

I want to appoligize about my comments about the hot motor issue. I just found out that the few motors that were produced were feild test motors and they are not for sale at this time. I am sorry if there was any confusion, however I wanted to let everyone know the facts.