More Power Wanted

[cosborne]

Not sure if this is the correct location to post this, but I have a 1996 Bayliner Capri 1950. It has the 3.0L Mercruiser. I was wondering what else I could do to make it go faster, without losing holeshot power. I am going to get a Stainless Steel prop. I have the stock prop on, which the pitch is 19. I was going to drop it to 17, which I was told that it could gain me 2-5 mph top end and help me out of the holeshot. I am new to boating, so I do not know what all I could do. I do not want to make it completely crazy like adding a V8, but I didn't know if there were some small things I could do to help. I do not want to through a bunch of money into it because I would like to get a newer one sometime (3-5 years). Any help would be appreciated.

Thanks,
Caleb

 

[achris]

Re: More Power Wanted

With the 19" prop on, what revs are you making at Wide Open Throttle?

 

[Haut Medoc]

Re: More Power Wanted

Welcome to iboats......
What AChris said....^^^^^^^
You will not be able to bump the engine HP, but a prop change might help......
You should be @ 4200-4600 @ Wot......​

 

[ziggy]

Re: More Power Wanted

if ya go from a 19 to a 17. yer gonna loose mph.. + gain holeshot... the ss will minimize these effects to a certain degree as ss don't flex like aluminim...whatever prop ya get. yer lookin to reach wot spec. on the high side with a normal load.. as for the 3.0 i don't know what to say......

 

[Frank Acampora]

Re: More Power Wanted

That boat also came with a 4.2 V6 as an option. Find a cheap 4.2 and put it in. You will go over 50.

4.2 is standard Chevy. get a newer one with fuel injection from an auto junkyard and you won't need to do much to marinize it. It's a bit of a project but the increase in speed will be well worth it. Don't know how long the outdrive will hold up to the extra torque and HP though.

 

[oops!]

Re: More Power Wanted

ok here we go.....

all of the above.....

the little 4 banger you got.....not much you can do....cheeper to go 6 cyl than trying to stuff a 4bbl on that thing....

however...k&n air intake filter...said to add 5 ponies....synthetic oil in the motor and drive will also give you a little more....and safely add 100 revs.
you also might look at loosing some weight in the bote....anything in there you dont need?

you are going in the right direction looking at props....you will need lots of playing with it...(trying different prop configurations)...to get a mesureable increase in top end.

please read prop topics...look at the graphs...for every 200 rpm you can add an inch of pitch...if your boat is at wot...4400...with a 21 p....you can drop to a 19 for 4600 rpm...prob gain a little.....
however if you are at 19p and 4600...dropping to a 17 will give you more hole but exceed the max revs you should run at.

it all sounds kinda complicated but after you read for a few hours here...you get up to speed quite quickly....

cheers
oops

 

[oops!]

Re: More Power Wanted

oh by the way......


welcome to i boats

 

[Bondo]

Re: More Power Wanted

Ayuh,.....

Keeping the 3.0l in Perfect Tune is all your going to Get for HP.....

If you don't like the Preformance available,......
Trade it for the boat you Really Want.......

Swapping in a 4.3l will mean you'll have Way More dollars into than it'll Ever be Worth......

 

[tommays]

Re: More Power Wanted

The 17" prop is going to drop your TOP speed about 5+ MPH and allow it to go WAY above the WOT of 4800 RPM


Trust me i own a 1995 Maxum 19' 3.0 and have MANY props



Tommays

 

[Alumarine]

Re: More Power Wanted

ok here we go.....

however...k&n air intake filter...said to add 5 ponies

oops

How can a K&N help compared to a flame arrester?

 

[gcope63]

Re: More Power Wanted

I have a K&N on mine, no change. supposed to be a better filter than the metal screen arrestor but no performance increase. It could add 5hp but you would not be able to feel any difference.

Gary

 

[dcg9381]

Re: More Power Wanted

I had to replace a 3.0L in a 4Winns once, due to the previous owner failing to winterize the thing. If I recall correctly, it was made across a 10-20 hp difference, I believe the main difference was in the manifold configuration and maybe the ports on the head...

The above advice is right though - if you really want more power, sell it and get a different boat. That's the most cost effective way to do it.
The 4.3L is a good motor: reliable, half way to a V8, reasonable power, easy to get parts for.

 

[achris]

Re: More Power Wanted

I have a K&N on mine, no change. supposed to be a better filter than the metal screen arrestor but no performance increase. It could add 5hp but you would not be able to feel any difference.

Gary

Gary,

That 5hp increase is over a paper element air filter, not a metal flame arrestor. Using a filter, any filter, will decrease your output, because the metal flame arrestor offers no resistance to air flow.

Chris..........

 

[cosborne]

Re: More Power Wanted

Thanks for the advice. The fastest I have had the boat was 40mph and I think the rpm was around 4200. I have thought about the 4.3L swap, but like I said, I do not want to through a bunch of money in it and not get it out or possible hurt the value. I think the best thing would be to get the prop for now and save my money and buy a bigger one later. Thanks again.

 

[180shabah]

Re: More Power Wanted

IF 4200 is correct, then dropping pitch to 17" should put you around 4600 WOT, improve holeshot, and not negatively effect your top end.

 

[oops!]

Re: More Power Wanted

ya i agree...if 4200 is wot...yer over propped

drop it an inch...(see walleyeheds prop test results)

youll only gain a mile or two....

mabe three if you get it perfect....

if yer lookin to go 50.....you need a new motor or boat....

btw...the k&n marine filter.....says on the package that it will give you 5 hp over nuthin at all......but then ...thats a sales pitch.....only yer motor knows for sure

oops

 

[Bondo]

Re: More Power Wanted

Ayuh,......

I'd say you're boarderline Over Propped.......

I'd think if you could see wot at 4600/4800 it'll really Wake Up your boat.....

 

[tommays]

Re: More Power Wanted

I think if you do the math on a 3.0 with a 1.98 gear ratio and 19" pitch at 40 MPH and 4200 RPM you would be getting -5 % slip numbers

Now a 1.98 ratio with a 19' prop at 4800 RPM gives 40 MPH at a 9% slip which is a bit optimistic


Tommays

 

[Don S]

Re: More Power Wanted

It doesn't matter what all the math says, if he has a 19" prop and ony gets 4200 rpm, then he needs a smaller prop.
Of course, if he hasn't been to wide open throttle to get an accurate number

The fastest I have had the boat was 40mph and I think the rpm was around 4200.

Then all bets are off, you can't adjust prop size without first knowing max WOT rpm.
Who knows, he may not have even had the drive trimmed to best position which wouldn't allow max WOT rpm or speed.

 

[achris]

Re: More Power Wanted

Those numbers don't make sense.... Screen grab...