Hey i need a little more power any ideas?

skysport32

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Jul 29, 2007
Messages
1
Hello i have a 3.0l o.h.m.c chevy 4 cyl 135hp motor and need more power. WHat can i do. I am considering supercharger, or turbo charger. Any help would be appreciated.

Thanks Justin
 

Bondo

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Re: Hey i need a little more power any ideas?

Ayuh,........

Trade the boat for 1 with a Bigger Motor.........
 

chaparral442

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Joined
Mar 25, 2007
Messages
153
Re: Hey i need a little more power any ideas?

Not sure how much power you mean- Marine engines are not like automotive- there is little you can do to increase power-
Make sure
1. You are operating at the max RPM power curve
2. Have the correct prop
3. Boat is at plane correctly- if you need a better hole shot consider SMART TABS- $120 do not even think about a hydrafoil
4. Use Synthetic Oil-
5. Rebuild Carb

That's about it-- if that does not do the trick, it is new or another used boat--

With a boat that size you might consider converting to an outboard-- you would reduce weight, gain interior space or storage--
 

Don S

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Aug 31, 2004
Messages
62,321
Re: Hey i need a little more power any ideas?

i have a 3.0l o.h.m.c chevy 4 cyl 135hp motor

OK, What does o.h.m.c stand for????
 

MikDee

Banned
Joined
Jun 6, 2007
Messages
4,745
Re: Hey i need a little more power any ideas?

Not sure how much power you mean- Marine engines are not like automotive- there is little you can do to increase power-
Make sure
1. You are operating at the max RPM power curve
2. Have the correct prop
3. Boat is at plane correctly- if you need a better hole shot consider SMART TABS- $120 do not even think about a hydrafoil
4. Use Synthetic Oil-
5. Rebuild Carb

That's about it-- if that does not do the trick, it is new or another used boat--

With a boat that size you might consider converting to an outboard-- you would reduce weight, gain interior space or storage--

I concur with these, along with them, here's a few more tips:

1) Make sure your throttle is opening all the way, at the helm.
2) Make sure your flame arrestor is clean, and has good airflow
3) Adjust your idle MIXTURE screw out (at idle) for the highest idle speed you can get (richest mixture)
4) Get a new set of spark plugs (I prefer Champion)
5) Make sure you have good spark plug wires, I mean metallic core suppression wires, if not get a set of spiral metallic core suppression wires to fit (you will feel the increase in power, if yours are crappy wires)
6) and again, get some synthetic blend, or full synthetic oil. (less friction)
 

chaparral442

Petty Officer 2nd Class
Joined
Mar 25, 2007
Messages
153
Re: Hey i need a little more power any ideas?

you sure it does not say OMC?

The only OHMC designation I know of stands for Off Highway Motorcycle
 

QC

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Joined
Mar 22, 2005
Messages
22,783
Re: Hey i need a little more power any ideas?

I am going with OverHead Mega Cam :eek: :D

BTW, Welcome skysport . . . We're kinda a precise group over here. The 3.0 is a great little engine that is pretty much maxed out. We always answer this question the same. Different engine and/or boat ;)
 

bomar76

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Jun 27, 2002
Messages
1,963
Re: Hey i need a little more power any ideas?

Get a piece of cardboard and a magic marker.
Wrire "FOR SALE" on the card board, put on boat.
Find boat w/ power you want and buy it.
 

chaparral442

Petty Officer 2nd Class
Joined
Mar 25, 2007
Messages
153
Re: Hey i need a little more power any ideas?

You will if not now eventually have to trade up- whether you go new or used-- take your time and let the folks on this forum advise you in your purchase-- LOTS of expertise and experience here that is invaluable
 

gojayo

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Jul 8, 2007
Messages
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Re: Hey i need a little more power any ideas?

Chaparral wrote "4. Use Synthetic Oil" as one of the things go increase power.

I'm not sure if it's true, but a mechanic told me in no uncertain terms to only use synthetic oil in an engine that is brand new or just completely rebuilt where the block was boiled...since using the synthetic somehow caused problems in engines where normal oil had been used. Maybe that requires a bit of research. I was going to use the synthetic in mine for the "power" reasons too, but decided against it.

I agree with everyone else about a different boat. BUT, and this is a big butt...if you totally LOVE the boat and will still love it after spending about $7,000 on a repower plus replacing bad stringers etc etc etc...and taking up about 2 months worth of every available moment and most of your brain...then I'd say go for it. With the time spent on the repower your girlfriend or wife will probably either leave you or have a new boyfriend, so your new fast boat will be great for hauling in the chicks.....
 

Bondo

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Re: Hey i need a little more power any ideas?

a mechanic told me in no uncertain terms to only use synthetic oil in an engine that is brand new or just completely rebuilt where the block was boiled...since using the synthetic somehow caused problems in engines where normal oil had been used.

Ayuh,......... IMHOpinion,.................... Bull$h-t............
 

bomar76

Lieutenant Commander
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Messages
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Re: Hey i need a little more power any ideas?

a mechanic told me in no uncertain terms to only use synthetic oil in an engine that is brand new or just completely rebuilt where the block was boiled...since using the synthetic somehow caused problems in engines where normal oil had been used.

That mechanic is an Idiot.
 

chaparral442

Petty Officer 2nd Class
Joined
Mar 25, 2007
Messages
153
Re: Hey i need a little more power any ideas?

old school, old wives tales-- I do suggest that you use a marine synthetic --there is controversy over this but merc and volvo swear they are having additives added for marine conditions--

Mine is under warranty and I will not argue over a few bucks.
 

tmh

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Aug 16, 2006
Messages
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Re: Hey i need a little more power any ideas?

So, even with a 20 yr. old I/O mercruiser, switching to synthetic oil is OK? Yeah, I had heard the same that it changing can cause problems....never new why.
 

JasonB

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Feb 10, 2003
Messages
1,455
Re: Hey i need a little more power any ideas?

In my experience, synthetic seems to clean an engine out. I think the oil leaks that have been reported over the years may have been from worn seals that were gunked up. When the gunk was removed.....

That said, I switched my truck over to syn at 120k. It uses less oil now.
 

95yj

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Feb 21, 2007
Messages
279
Re: Hey i need a little more power any ideas?

Synthetic oil, brand new motor??? New motors don't break in well running synthetic. When you break in a motor, you need rings and bearings to seat at multiple RPMs which is why you run the motor at different loads / R's. Break in the motor on a good quality oil and then if you want to run synthetic, do so after the break in period.

It still comes down to, if you take care of the motor during it's life, any quality oil will do the job. If you miss a few changes, a better oil may help get past those. Either way, maintenance is more important than putting $15 vs. $4 a quart oil.

Everywhere I've ever read states that you don't run synthetics during break in.
 

chaparral442

Petty Officer 2nd Class
Joined
Mar 25, 2007
Messages
153
Re: Hey i need a little more power any ideas?

Depends on the engine. Some engines are Dyno'd before delivery and break in is not necessary but if in doubt run her 25 hours with varying speeds then change
 

poolmedic

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Joined
Jun 22, 2007
Messages
8
Re: Hey i need a little more power any ideas?

Just my point of view,

The reason I had always heard for not switching was that Mineral/conventional oil used over a long period of time may build up sludge in the crankcase and on top of the heads. going to a full synthetic oil change would clean off all the sludge all at once. This could plug up the filter and/or oil pump reducing the flow of oil.

I've been told that with an older engine that has run on conventional oil for a long period of time that you:

1. Change the oil and filter with new conventional oil short 1 Qrt.
2. Add 1 Qrt. of synthetic to top off the dip stick.
3. Run engine for 20 - 30 hrs.
4. Change filter only and top off with more synthetic.
5. Run another 20-30 hrs.
6. Change oil and filter with all synthetic and monitor oil level and color and change as needed or regular interval.

Just one school of thought.

Randy
 

MurphysLaw

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Joined
Jul 28, 2007
Messages
29
Re: Hey i need a little more power any ideas?

syn oil is too slippery for an old motor. The seals will not be able to stop it, Id suggest sticking to the high mileage or conventional oil because if you have an oil leak, that will go into the water=bad stuff. Case in point-my truck has 146K, i tried full syn and the rear main seal started leaking, which it has never done before. I have used high mileage oil for the past 6k and now the leakage has stopped, ever noticed that the high mileage oil is not full syn?
 

PhilDx

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Joined
Jul 17, 2007
Messages
12
Re: Hey i need a little more power any ideas?

High mileage oil has additives to help control leakage due to wear and seal aging. Full synthetic oil has very good resistance to breakdown due to heat and contaminants. Horses for courses...
 
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