More hp out of 1993 3 litre181cid IO

"Hi All,

I am a new owner o

"Hi All,

I am a new owner of a hurricane deckboat powered by the above engine. I am getting a little water into the oil pan - and I suspect that the (rusted out?) exhaust manifold is to blame.

As a result, I will soon be removing both the exhaust manifold and head to identify where the water is getting in. Here is my question - can I do anything while I am performing this work to increase the horsepower ? For example, is there a high performance head or exhaust manifold I can install ?

I believe that the boat as originally equipped is rated at 130hp. This is just barely enough to get me out of the water on one ski.

Thanks"

"If all your after is to get o

"If all your after is to get out of the water on skis, I would have the prop re-pitched or order a new one."

Your water in the oil is more

Your water in the oil is more than likely not the manifold and riser. You don't specify the boat size but the the best way to get a better hole shot is to go down in pitch on the prop. There are no high performance parts to put on the engine with out major modifications.

"You likely have an Alpha One

"You likely have an Alpha One Gen II drive. If your water problem turns out to be major, you could always repower with a 4.3L V6, or even a 5.7L V8, rather than spend a bunch of moeny on a new 181. That will get you up to 190 hp or 290 hp respectively. This assumes that the engine compartment will handle the larger engine, and that the boat is rated for this kind of weight and power. The Alpha One drive is rated for up to 300 hp.
You would have to also change the upper drive gears to get 1.81 or 1.47 drive ratio respectively, to keep prop pitch within reasonable limits. Your current ratio is likely about 2.0; which is too high for the larger engines.
I would not waste time on a 5.0L V8; it's the same weight as the 5.7, and is kind of a dog, IMO.
Hope that helps, Rod"

"Thanks for the ideas.

Mine

"Thanks for the ideas.

Mine is actually a Yamaha Stern Drive as my username suggests. I posted here because there is no Yamaha stern drive section of this web site. Yamaha only made stern drives for a few years - and that was about a decade ago. My Hurricane deck boat is about 20 feet long, weighs nearly 3,000 pounds dry, and has a very large engine compartment - it could have been ordered with a 5.7.

How does water usually get into an oil pan ? Is it usually a terminal condition ?

Did I hear that a 4.3 litre bolts right up to the same stern drive as my sick 1993 vintage 3 litre ?

My brother in law has a 2000 four winns with the 4.3 litre. I really like how that engine functions in his boat!

Thanks}"

"Jim; very sorry that I assume

"Jim; very sorry that I assumed it was a Merc. I did not even notice the yamaha reference in your user name, to be quite honest.
I have no idea about compatability of your drive with different GM engines, or what power it will handle. Maybe someone else on this site is knowledgeable in these areas.
If your 181 has a terminal problem, perhaps you should consider a complete new 4.3 or 5.7 Alpha drive package, and replace your whole package. You will need to check and see how different the transom openings are.
From what I understand about water in oil problems, it can be anything from a simple leaky head gasket to a leaking exhaust manifold, cracked block, cracked head, or who knows? A compression or leakdown test may help to pin it down.
If it's something major, I wouldn't spend any money replacing an engine that you are not happy with in the first place. Having said that, I note there are a couple of rebuilt 181 engines on Ebay for around $2100.
Good luck,
Rod"

Not to worry Rod - it was I wh

Not to worry Rod - it was I who put the Yamaha in the Merc section.

The compression check was great. And the engine seems to run very well - once the pinging causing moisture has boiled away during warm up.

I am hoping to see the problem by just removing the intake and exhaust. I'll bring the intake to a shop to have it inspected and repaired if necessary.

Take Care

Jim;
Good to know the compres

Jim;
Good to know the compression check was good. Now where is the water coming from?
I hope that it turns out to be something simple such as head gasket or manifold.
Good luck!
Rod