5.7 230hp, pushing 1993 240 Sea Ray, HELP!

[Utah Husker]

Gents,

First off, thanks to all the guys who give me input. I do need some help with this one.

Last week, I bought this off my dad in Iowa (elevation 1473 ft);

1993 Sea Ray 240 (24') BR
Mercruiser 5.7 (230hp) ugh!
Alpha One (1.5 gears)
Stainless Prop (14.5 dia by 17 pitch all beat to crap)

http://www.searay.com/boat_graphics/sea_ray_prop_charts/1993.ENGINE,DRIVE AND PROP MATRIX.pdf

And brought it back to Salt Lake, Utah (approx 5100 ft) and will run it mostly at Lake Powell. (3650 ft)

Things I know;

I took it out on Utah Lake with half tank of gas (ethonal crap I need to burn out at 88 octane) and just me, for weight, a stainless 15.5 x 17 prop, (too wide, borrowed cause it wasn't dinged up) and only got 3200 RPMs W.O.T. (should be 4600) at 31mph (not gps)

1. I need to tune-up, retime, and reprop this baby (14 x 19) to at least see where I am at.

2. My gut tells me to scrap this 5.7 powerplant for a 7.4, but my pocketbook says otherwise.

So...my challenge to all who are reading this is;

What is the most cost effective way to push my crappy 230hp up to 270-300 hp (300 is max for Alpha One)?

I am thinking cam, intake, carb from edlebrock, or something along those lines. Any better ideas???

That's my challenge, thanks for the help.

I am off to tune and buy the right prop to start.

 

[maxxman04]

Re: 5.7 230hp, pushing 1993 240 Sea Ray, HELP!

as far as engine goes, invest in the ignition system as well. the rest of the parts you mentioned won't mean a thing if you have insufficient fire. higher output coil, and low resistance wires. take an ohmeter to store with you, start with stock replacement wires, get a baseline reading for stock type wires, you'll be surprised at how much resistance there is. then go from there. a top name doesn't always mean better either.

 

[Utah Husker]

Re: 5.7 230hp, pushing 1993 240 Sea Ray, HELP!

I found the timing set at 8 ATDC. It should be 8 BTDC @ 650 RPMs. I timed it right now. I don't know how much HP I lost due to 16 degrees advanced.

It start right off now. (No pumping or flooding.)

This with the correct prop...I am optomistic on my test run tomorrow.

Also got details from Edelbrock today on 300hp package.

Anyone know if a '93 Mercruiser can accept all small block after market parts (prior to TBI)?

 

[Utah Husker]

Re: 5.7 230hp, pushing 1993 240 Sea Ray, HELP!

And thanks for ignition wire suggestion...I'll let you know.

 

[Bondo]

Re: 5.7 230hp, pushing 1993 240 Sea Ray, HELP!

What is the most cost effective way to push my crappy 230hp up to 270-300 hp (300 is max for Alpha One)?

Ayuh,... A set of Vortec Heads, matching Intake,+ a 4bbl. Carb....
Leave the Cam alone, you don't Need 1...

The Vortec Heads with the 906 casting # is supposed to have larger exhaust valve seats that the 669s do....
So,.. I'd search for the 906s...

 

[wca_tim]

Re: 5.7 230hp, pushing 1993 240 Sea Ray, HELP!

as far as engine goes, invest in the ignition system as well. the rest of the parts you mentioned won't mean a thing if you have insufficient fire. higher output coil, and low resistance wires. take an ohmeter to store with you, start with stock replacement wires, get a baseline reading for stock type wires, you'll be surprised at how much resistance there is. then go from there. a top name doesn't always mean better either.

I disagree that this is a worthwhile investment. the thunderbolt iv on the boat is a great ignition system and coupled wires in decent shape and the right advance module for the application you'll see approximately zero increase in oerformance with a high dollar aftermarket ignition system. Much better ways to spend performance dollars in this situation.

 

[wca_tim]

Re: 5.7 230hp, pushing 1993 240 Sea Ray, HELP!

Hopefjully your follow up with the timing set right will be better - perhaps mid to upper 40's or better?

even if you wanted to spend more on an engine, a big block is not the way to go. a stroked small block can perform as well or better than all but a really healthy big block build without the additional weight, etc... and sure, you can push more through an alpha drive, just keep a spare around....

Bond-o has the ticket for what you're thinking about on a reasonable budget.

be very careful with the performance packages - what works for a car will many times eat itself in a boat. the demands are much heavier on a boat engine, and there is the consideration of wet exhaust and reversion (a cam with much overlap at all will suck water back into the engine with stock exhaust manifolds, aftermarkets start at a grand or so).

Hope this is helpful. lots of good info on here if you search for it a bit. good luck

 

[lime4x4]

Re: 5.7 230hp, pushing 1993 240 Sea Ray, HELP!

A vortec 350 would help. I speak from expereince. I have 268 searay weekender this boat when on the water weighs around 8000lbs. The old 350 chevy engine that was in would take 1 min and 25 seconds to get the boat on plane. Once i dropped the vortec engine in i can now be on plane in 13 seconds.The stock chevy vortec engine is rated at 250 hp 330 lbs of torque. Now throw in a daul plane intake a performance roller camshaft and you got yourself one torquey power plant

 

[maxxman04]

Re: 5.7 230hp, pushing 1993 240 Sea Ray, HELP!

Bond-O has the right idea. the vortec heads have been proven to flow just as good, in some cases better, than other aftermarket heads, with a fair increase in power with heads alone. add in the right manifold, performance carb, easy power.

 

[maxxman04]

Re: 5.7 230hp, pushing 1993 240 Sea Ray, HELP!

and to clarify, the thunderbolt ignition is definately a great system, but even the wires that come stock with that system do wear out over time, more so in marine applications. wca tim is correct that upgrading the distributor, ignition module and such would surely prove to be a waste, however the plugs and wires are something to keep an eye on, and replace with quality parts.