More Power!

[Susquehanna Squid]

Does anyone have any ideas on how to increase power and or speed without a major overhaul.......or buying a new boat? I have a 2006 Monterey 180 FS and I love it. The thing is like new (160 hours) and looks great. It currently sports the typical 4cyl. 3.0 GM engine with the Volvo Penta outdrive. It is carbureted with a Holley and I believe the prop is the recommended 14 1/2 by 19. I have added an aftermarket swim platform and some other goodies so I finally have it just how I want it.... except for the power! Most of the time I am happy with its performance but when I am pulling a tuber etc. I want more power. Can I drop a V-6 in it easily and still use the same drive? Would it be too heavy? Any thoughts or advice is greatly appreciated. Thanks, Kevin!

 

[MikDee]

It would be a lot of work, money, & time to convert to a V6, not worth it IMO. Why don't you try putting synthetic oil in it 1st! Then venting the prop, it is an easy procedure, that can be reversed easily as well. Here's the scoop!:
http://www.marinemechanic.com/site/page76.html

These few items should give you a power boost, and make you appreciate that 3.0L even more Don't fix it if it ain't broke, just get a more powerful boat.

 

[Susquehanna Squid]

Thank you sir! I assumed that a re-power would cost a fortune but thought the heck. I think I have to just be happy with what I have because the rpm's are actually around 5k with just me in the boat WOT. I believe 46 to 48 is what is recommended! The max MPH is about 40-42 according to my Garmin which is great I think but I was just wondering if there were any way to boost it inexpensively. Does the synthetic oil make a big difference?

 

[doyall]

... Does the synthetic oil make a big difference?

Speed wise? No ... period, and do not allow anyone to convince you differently. Yes, there are other benefits of synthetics in many applications but 'speed' is not one of them. 5,000 RPM is 5,000 RPM. Synthetic oil is not going to make the boat any faster at WOT because it is not going to increase your WOT RPM. I would even venture to say that synthetic will not give you any more useable power (i.e., torque) either.

You can also vent your prop, but don't expect, as they say, to make a silk purse out of a sows ear. Venting will not do anything the butt dyno can discern. I've had 'em on a 3.0L and can speak from experience.

 

[MikDee]

Speed wise? No ... period, and do not allow anyone to convince you differently. Yes, there are other benefits of synthetics in many applications but 'speed' is not one of them. 5,000 RPM is 5,000 RPM. Synthetic oil is not going to make the boat any faster at WOT because it is not going to increase your WOT RPM. I would even venture to say that synthetic will not give you any more useable power (i.e., torque) either.

You can also vent your prop, but don't expect, as they say, to make a silk purse out of a sows ear. Venting will not do anything the butt dyno can discern. I've had 'em on a 3.0L and can speak from experience.

I say B.S.! Synthetic oil is lower friction then regular oil, so it has to increase power! I've noticed cooler, smoother running as well, if you can't tell the difference then you're probably doing something wrong! Plus there are plenty of threads on prop venting, and it's positive results all over this forum, and Mercury actually sells vented props in certain models, so I guess they're wrong too! I posted this prop venting link, so that members can get a handle on how easily it is to do it themselves, there's no black magic to it.

 

[doyall]

I say B.S.! Synthetic oil is lower friction then regular oil, so it has to increase power! I've noticed cooler, smoother running as well, if you can't tell the difference then you're probably doing something wrong! Plus there are plenty of threads on prop venting, and it's positive results all over this forum, and Mercury actually sells vented props in certain models, so I guess they're wrong too! I posted this prop venting link, so that members can get a handle on how easily it is to do it themselves, there's no black magic to it.

"Cooler, smoother running" - perhaps. "It has to increase power" - prove it up in the OP's application, otherwise you need to quit spouting such nonsense. I suppose it will also increase the OP's WOT RPM. You must be an Amsoil salesman.

Vented props - MAY provide some marginal benefit but nothing the OP will be able to discern without precise measurement.

 

[Howard Sterndrive]

you might get 1 or 2 horsepower from synthetic oil. But it takes 10+HP to go even 1mph faster. There won't be any noticeable speed or power increase. Throwing 5 pounds of unnecessary weight overboard probably about equal.

I repowered my 18' Bayliner from a 3.0 to a V6, but it wasn't cheap, easy or quick. I actually have repowered 2 boats from 3.0 to V6 now. I just like wrenching on boats and I had a free motor so I did it. And no you can't use a 3.0 gear ratio drive behind a V6.

 

[MikDee]

All these mods are cumulative, and Do make a difference when combined! If you're willing to give them a shot!
I see we have a coupla naysayers here, or "party poopers", so be it.

I coaxed an old 20ft SeaRay bowrider with a 228hp/305 chevy to a max of 50mph fully trimmed out, by putting in thru-hull exhaust, stainless steel plug wires, ACMR43T spark plugs, synthetic oil, and mixture screws turned out to the highest idle speed (they're usually set to the leanest point from the factory), plus, a waxed unpainted bottom, and a Black Max 19" Alum prop (mind you)! And this was old school design in 1979. Imagine how a new 305 or 350 Vortec would respond to this nowadays?


Did the same thing to my next 24' SeaRay Cuddy , and got it to 40mph with the old school 350/260hp Mercruiser, using the same type 17" pitch Alum. prop

By the way, you could get an exhaust tube, instead of using your exhaust bellows, for some nice sound, & possibly more power?

Or, like back in the 50's, & 60's, you could put thru hull exhaust. Like the old style inboards at the time, it might even sound better like an old English 4cyl sports car,,,lol

 

[Yankeyspeed]

Is yours a carb? Also I think your better than a lot of us with the LX head. I think the intake and exhaust manifold could yield more power. I agree with keeping the boat weight in check. I am just about done with my 3.0 spark arrestor. I doubled the thickness.

 

[thumpar]

It takes a good amount of power to increase speed. If you want more power sell the boat and get one with the power you want. It will be cheaper in the long run.

 

[Walt T]

I say buy a boat that does what you want or live with what you have. Synthetic is good stuff but any power increase will not be noticeable

 

[no704]

Could just put a little NO2 on it that would wake up your tubers.

 

[Susquehanna Squid]

Thanks for everything guys! Guess I will stay put with what I have..........for this year!

 

[achris]

When Merc were experimenting with EFI on those engines, they managed to get about 15 horsepower more, but not for very long. 140hp is about the limit of that lower end... After that, it comes apart.

As for synthetic oil, it might add 1 or 2 hp, absolutely nothing that would be noticed with the 'butt-dyno' or the GPS. Speed increase uses the rule of squares. To double the speed, you need 4 times the horsepower. If you are getting 40mph with 140hp, then to get 80mph you would need about 560hp.... Even an increase of 5 mph would require an increase of around 60hp... And you ain't gonna get anywhere near than from that little 3 litre... even with through-hull exhaust (which BTW will sound terrible, like one of those 'rice-burner' car the young set 'drive')... or an exhaust tube rather than the bellows. Just not enough flow to warrant a change in any part of the exhaust.

Venting the prop will increase the acceleration at the bottom end, but actually DECREASE the top speed.

Chris....

 

[HT32BSX115]

Yeah. The specific fuel consumption and specific horsepower doesn't change a lot for any gasoline marine engine unless you do some very specific "things"

If you want an engine to produce enough "mo" power, you'll need to "stuff" a LOT more fuel into it. To do that, you'll need to stuff MORE air into it too.

That's ONLY going to come from more cu-inches OR supercharging (turbo or eng-driven) AND, it's going to take a LOT of $$$ (and supercharging will eventually get you an engine- "Kaboom" if you push it too hard.......)

Snake oils, water injection, fuel magnets, incantations, and/or other superstitions will also suck money out of your wallet but not give you much more top speed or hole shot.

Cheers,


Rick

 

[JustJason]

~~
I say B.S.! Synthetic oil is lower friction then regular oil, so it has to increase power! I've noticed cooler, smoother running as well, if you can't tell the difference then you're probably doing something wrong! Plus there are plenty of threads on prop venting, and it's positive

My Toyota Tundra calls for 0W20. As Toyota says it allows the engine (5.7) to get better mileage and build more power. I throw 10W30 in it because it makes me feel better, and the engine isn't as noisy when you start it up. I notice no difference in economy or power. It still gets the same crappy fuel mileage, and still makes megatons of power.

On this boat here. If the OP's major concern is when pulling a tuber. His best bet is to go with a high performance prop, like a 4 bladed vented stainless. A set of tabs would be the next best thing, but I don't know if he will have room given the swim platform.

 

[aerobat]

I coaxed an old 20ft SeaRay bowrider with a 228hp/305 chevy to a max of 50mph fully trimmed out, by putting in thru-hull exhaust, stainless steel plug wires, ACMR43T spark plugs, synthetic oil, and mixture screws turned out to the highest idle speed (they're usually set to the leanest point from the factory)

sorry to say this, but the best plug or plug wire cannot do more than ignite the mixture. how hard it bangs inside the cylinder is not more under the influence of the plug or plug wire. the same applies to the mixture screws. i,m absolutly sure you understand that these are idle mixture screws and affect only idle mixture where the mixture at WOT is affected by the main jets where there are no adjustement screws for . so visiting the toilet for weight reduction before the ride will bring more performance boost than your special wires or mixture screws when it comes to topspeed.

 

[bruceb58]

i,m absolutly sure you understand that these are idle mixture screws and affect only idle mixture where the mixture at WOT is affected by the main jets where there are no adjustement screws for

He wouldn't be the first one that thought adjusting idle screws did anything other than at idle. Amazing how many people think that it makes a difference.

One less qrtr pounder at lunch time would do as much for top end speed as the synthetic oil provides.

I am not even going to comment on stainless steel spark plug wires! :facepalm:

 

[Susquehanna Squid]

I love the conversation here guys! Thanks again. I think I am going to try to add some pixie dust I bought off a guy with some oceanfront property in Kansas!

 

[MikDee]

sorry to say this, but the best plug or plug wire cannot do more than ignite the mixture. how hard it bangs inside the cylinder is not more under the influence of the plug or plug wire. the same applies to the mixture screws. i,m absolutly sure you understand that these are idle mixture screws and affect only idle mixture where the mixture at WOT is affected by the main jets where there are no adjustement screws for . so visiting the toilet for weight reduction before the ride will bring more performance boost than your special wires or mixture screws when it comes to topspeed.

So then, I guess the idle mixture flow shuts off as you increase the throttle? Yes, No?,,, I also suppose that it's only my imagination that my vehicle runs smoother, and better in the rain, or under load, and even pulls better then before with a good set of plugs, and solid metal core wires (as opposed to fiberglas strands with carbon over them as in "stock factory" wires). I also suppose then that all the dedicated racing wire manufactures are wrong? More complete burn of your compressed mixture is tantamount to power!
So, go back to your shell, and don't bother coming out until you say something that makes sense