Looking for new boat: Engine size vs boat length/weight question

Good morning.

I'm still looking for a 24-26' Express Cruiser as some of you might be aware. Fun & time consuming process. Learn quite a bit about boating in general, but still no where enough to arm myself yet.

1) So can you please help me with any rule of thumb on the power (HP rating?) of the engine I should be looking for?

- What's a min engine size for a 24' (~5000 +- a couple hundred lbs)
- Average size?
- "Powerful"/plus size?

I saw some of the replacement engines on older boats (96-2001) have 5.7 Volvo Penta 320Hp. Some the of original is only ~260HP. But can't relate them yet.

2) If average maintained, how long the engine should last before a rebuild/major is required? How much is a ball park guestimate for this?

3) If it has a closed cooling system, does that mean salt water proof? I plan to take it out the Bay (CA) once in a while. With good clean up, will it still keeps my boat as clean as a fresh water only boat?

4) anything other general important points I should know at this time (pre-purchase)?

Thank you.

Nhi

Re: Looking for new boat: Engine size vs boat length/weight question

My 1984 engines don't appear to ever have been overhauled or rebuilt short of risers and possibly manifolds. They are low hour (for the year) but still run well and I expect many more years out if them.

A lot of people swear on flushing any motor after salt water use. If your mainly fresh and only venture into the salt, you shouldn't have any additional problems (my opinion).

As far as minimum power, I'd stick with a 5.7 (possibly a 5.0 MPI), for any boat your looking at. If you can find a bigger small block or big block that might be a plus.

Re: Looking for new boat: Engine size vs boat length/weight question

get a big mtr, not to big though. will last you as long as fate has decided.

Re: Looking for new boat: Engine size vs boat length/weight question

Hai Nhi said:

Good morning.


1) So can you please help me with any rule of thumb on the power (HP rating?) of the engine I should be looking for?

- What's a min engine size for a 24' (~5000 +- a couple hundred lbs) 5.7L
- Average size? 7.4L
- "Powerful"/plus size? 454 Magnum/496/8.1

I saw some of the replacement engines on older boats (96-2001) have 5.7 Volvo Penta 320Hp. Some the of original is only ~260HP. But can't relate them yet. I would be skeptical of the actual horsepower on a replacement engine. Let the sea trial do the talking

2) If average maintained, how long the engine should last before a rebuild/major is required? How much is a ball park guestimate for this? 1200 hours

3) If it has a closed cooling system, does that mean salt water proof? I plan to take it out the Bay (CA) once in a while. With good clean up, will it still keeps my boat as clean as a fresh water only boat? Closed cooling system is similar to the cooling system in a car. Except for a radiator, there is a heat exchanger where hot water from the engine is cooled by cold(er) water from the ocean/lake. There are 'half' and 'full' systems. The difference is that the 'full' systems cool the exhaust manifolds with the engine coolant, the 'half' systems cool the exhaust manifolds with sea water. For salt water exposure, you really want a 'full' system to avoid deterioration of the exhaust manifolds.

Salt water is still brought up thru the outdrive and into the heat exchanger and then out the exhaust elbows, so there is some exposure to salt water and related maintenance, but far less than full exposure to salt.

4) anything other general important points I should know at this time (pre-purchase)? Many boats are under powered with their 'standard' engine package. Cruisers are more noticable regarding power, because they are more heavier for their length. Also pay attention to the 'deadrise' on the hull. That is the angle of the 'V' in the 'V hull'. Since I boat in the ocean, and my local waters are choppy, I looked for a boat with a high deadrise angle (24 degrees). Lower angles are not going to take the rough waters as well and will pound the water as you go over waves. you typically see less deadrise angle in "lake" boats and higher deadrise angle in "ocean" boats.

Thank you.

Nhi

Click to expand...

Nhi:

Looks like you have been staying up all night with this boating stuff. . .

See my answers in your quotation above. . .

Re: Looking for new boat: Engine size vs boat length/weight question

tpenfield said:

Nhi:

Looks like you have been staying up all night with this boating stuff. . .

See my answers in your quotation above. . .

Click to expand...

Sadly Ted.

I stood up, but then sat down 15 mins ago to do one more search on places to go in the Bay so I can ... sweet talk to my wife, drawing beautiful near future. Hahaha. Then I see your post here. Told yah, it's addicting. But that's probably me. When I buy some thing big, I tend to over explore things.

Alright, I gotta get some sleep for safe driving tomorrow. Man, gonna get yelled at if I get in the bed now. hehehe.

Nhi

Re: Looking for new boat: Engine size vs boat length/weight question

Couple points to add

My 1999, 24' Chris Craft express weighed over 5K pounds dry and ran beautifully with a TBI 5.7 Volvo (280 hp) with duo-prop. It would top out at 40+ mph on those rare occasions when water conditions permitted. A friend has a 26' Maxum express with 5.0 MPI and Merc Bravo 3 (dual props again) and he can hit the high 30's. Another friend with a 1992, 25' Larson Hampton (another express cruiser) has a 5.7 Merc songle prop. He's never felt he needed more power. It all depends on how fast you want to go. In any event, a 5.7, or a 5.0 injected motor will provide over 30 mph at the top end. More power is usually better, with little increase in fual consumption as the bigger motor doesn't work as hard.

Longevity? The 1999 Chris Craft and my current boat (1997) had/have raw water cooled engines and the original blocks. The friend with the 1992 Larson is running the original block. Another friend's 1987, 30' Searay is running the original block. All of us wet slip all summer in salt and none of us flushes the motors. If a boat you're looking at has a closed system, so much the better.

An express cruiser in the 24-26' range is going to have a deadrise of between 17 and 20 degrees at the transom. Nature of the beast. They're built to be reasonably quick, fuel efficient and useful in protected and semi-protected water (bay or intracoastal). That and other design limitations keep them from being true 'blue water' boats. My Chris*Craft was VERY unusual in having a 22 deg. deadrise hull, something you just don't find in that class of boat. It handled rough water better than my 27' does at 17 deg, but I haven't seen another express like it and I still wouldn't have done any regular ocean running in it- it wasn't made for that.

Re: Looking for new boat: Engine size vs boat length/weight question

Would a boat with 5.7 320 HP Volvo allow you to play any ski/wakeboard okay? I'm not in for speed. But I'd like to tow a ski/board once in a while. Mainly for cruising, relaxing, sight seeing, not bypassing anyone.

Nhi