454b5 350 HP compaired to 57bs330 HP

"If you replaced twin 454'

"If you replaced twin 454's with twin 5.7's, how big a performace drop would there be? The vessel weighs 35,000 lbs. I'm told that it's not the loss of 40 HP that would make a big difference, it's the cubic inch loss. I believe the 5.7' are 350 CU. Is it torque or something like that, that would make this a bad move?
Nightstalker"

"My experience in going the EX

"My experience in going the EXACT opposite way has been that despite the larger and heavier engines, my fuel consumption has gotten better. Torque is a factor and as a result I am also able to turn larger props...effectively like changing gears."

"WOT torque spec @ peak on the

"WOT torque spec @ peak on the SB is about 300lb-ft. On the BB its about 400lb-ft. The weight diff in the 35,000 pound boat is not a factor. It is true, that at 300HP settings the tricked up SB may perform almost as well as the lower speed BB. However, that SB will not last too long at 300HP, I fear.
If you want to plane that boat to faraway places with any gas engine, you will pay dearly in fuel. You might consider setting it up as a trawler and run it at hull speed ~ 10kts or so."

Diver dave is right. If you pl

Diver dave is right. If you plan on crusing at hull speed the 5.7's will save alot of fuel. My dad had a 1990 38' egg harbor with 454's and at 3500rpm it was going 18mph.It would turn 4200rpm wide open at 26mph. After buying new wheels with less pitch the 350's would probably need to turn 4200-4500rpm for cruising speed. My guess is after 800-1000hours they would be shot.

"The plan is to run her slow a

"The plan is to run her slow and not very often at that. The vessel is basically a live a board for 4 months a year. I don't know where to go from here. The broker called this morning to tell me that the mechanic still can't believe the first compression test (cold-very low compression in both engines). Now, he tells me that if this second, warmed up test is good, I have to pay for it if I buy the boat. I don't know about launching and retrieving. If I walk away, after the test, he gives me my full deposit. I'm getting a real bad feeling about this whole mess. I still can't believe that this second test will be any better unless the mechanic had a bad tester the first time (then I'd really be PO'd).
Nightstalker"

Under-powered boats--think Bay

Under-powered boats--think Bayliners!--are gas hogs.

Jeff

You sure are right about that.

You sure are right about that.
Gary

I walked away from the deal. I

I walked away from the deal. I was getting too many bad vibs. I'll keep looking. Thanks for all of your advise. I have a feeling your input saved me a whole lot of bucks.
Thanks again
Gary

"They won't be gas hogs at

"They won't be gas hogs at hull speed. A few things:
1.How long do you plan on keeping the boat? 10 years from now we can assume gas prices will be double and many people will be using their boats as cottages so the lack of power won't be an issue. If you only plan on having the boat 2-5 years I wouldn't do it.
2.In this market I would think, given what you will spend on new engines and the boat, you could get a "turnkey" boat for the same price.
3.Generally you pay for the survey and or engine survey and if you walk you get your deposit $ back but you are out the survey money. Sounds to me if you buy the boat, the seller would gladly pay for the second compression test no matter what the results are."

My post was being typed as you

My post was being typed as you posted your response. I think you did the right thing.