engine replacement

[1979checkmate]

Hey everyone,
I am looking at a 2002 crownline deckboat that is in need of a new engine. The Stock engine is a carb 5.0 v8, if i purchase the boat i would like to move up to a 5.7 v8. I am exploring my options. I am looking at both new gm crates and Rapido remans (if there are other good options let me know). The GM is just a couple hundred more than the rapido. Would i be better off going with the GM New motor, with a marine cam or the Rapido. I could replace the Freeze plugs in the GM with brass, although i live in the midwest and the boat will never see salt water, so that may not even be necessary. Also, what generation would the block on a 2002 mercruiser 5.0 be? 2 piece or 1 piece rear seal?

 

[Pete104]

Re: engine replacement

www.usengine.com
There is way more to it than "brass freeze plugs"!

 

[Bamaman1]

Re: engine replacement

You didn't say if your motor is blown in the Crownline, or that it just may be a little too small of a motor for the boat. I personally have never seen any inboard outboard with a worn out engine. They're usually replaced due to lack of draining the water in the Fall and they froze up.

Once inboard outboard's plane out, they're usually run pretty fast--relative to the horsepower they've got.

If your boat is just a little slow coming out of the hole, I would suggest you keep the 5.0 engine in it and invest $450 in a set of Bennett trim tabs. You can plane out a boat at 10 mph, and hold it there. Getting the nose down in 1 second makes it pull like it's got 50 hp more. When at speed, if there are any fat people on one side, you can level up the boat. Hydraulic trim tabs are not for bass boats or pontoons, however on full hulled pleasurecraft--they're priceless.

I had a friend that forgot to drain his 5 liter Mercruiser engine and it froze in the Winter. I contacted my boat mechanic that lived and breathed old Grey Marine inboards. He gave me the parts number of a 5.7 liter GM Mr. Goodwrench industrial motor that would fit the motor mounts of a Mercruiser. (A regular junk yard 350 Chevy engine won't fit.) He switched out the motors, and it performed great. He saved big $ by using the GM crate motor over Mercruiser. Online, any of the bigger sellers of GM crate motors should know the parts #'s for their engine that can be used for marine use.

 

[Brentathon]

Re: engine replacement

Hydraulic Trim Tabs are nice, but power at the prop is MUCH more effective. If you don't mind gas/cost/weight, upgrade to a 5.7 if you have any desire for more power.
Having both trim tabs down also creates more drag, and handling is affected.....I'm not a big fan of the effects, and therefore I mainly use mine to level-out uneven load.
I wish I had some more power.....would like my boat to get on plane easier with 8 people; therefore, I usually limit to 6 or 7 people.

 

[1979checkmate]

Re: engine replacement

The boat was not winterized properly by the PO, has a cracked block.