Marine power engines

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.

JEP

Veteran Member
Joined
Oct 28, 2014
Messages
25
Location
USA
Vessel Make
34' mainship motor yacht
My mainship is equipped with marine power twin 454 gas burners, is anyone familiar with this engine. Nothing wrong just curious on performance
 
There is one in my assistance towboat that has been flawless for 12 seasons. It has around 4000 hours on it in some of the hardest service an engine will see...it just keeps chugging along.

As far as performance, it depends on fuel delivery system as in type of cab if that is present and how the boat is run. Or are you looking for boat performance specs?
 
Last edited:
  • Like
Reactions: JEP
I think they are 370
 
Good well proven engines. If it has the Sherwood raw water pump I would chunk that bugger overboard. Jabsco replacement is much better and way easier to work on. Check or change the exhaust elbow before it destroys the engine by rusting thru and leaking water into the cylinders. Quadrajets are good carbs (if thats what they have) until the secondaries open, primary venturi fuel control is excellent but the secondaries only have a rudimentary setup with jets and tapered rods controlled by a spring loaded flapper and a high speed pull over function. Read :very poor fuel control. If you have the Holley carbs,,, you have my sympathy. Some had Carter AFBs which are good, and very easy to work on. If you have points ignition changing out to the later HEI will help tremendously, especially on startup. These engines have a very good supply of parts available from the "hotrod" market place. If they are counter rotating one will have a gear driven camshaft, the other will have the standard chain drive. Distributers turn the same direction, crankshaft turns backwards on one engine. Fuel injection would be high on my list of wants. The 454 has been one of my favorite engines.
 
  • Like
Reactions: JEP
Marine Power is located in Ponchatoula, LA. They have been around along time- I THINK they were purchased by Donovan Marine a few years back. Still a very viable company with a great product. We take care of their three Toyota forklifts.
http://www.marinepowerusa.com


1983 Present 42 Sundeck
Twin Lehman 135's
✌️
 
  • Like
Reactions: JEP
Do the la people winterize your water tanks? And to what degree. I still like putting around, just don't know to what degree to winterize here in the south
 
JEP,
I never have-


1983 Present 42 Sundeck
Twin Lehman 135's
✌️
 
Speaking of Marine Power engines on a Mainship, we just bought a 1996 Mainship 37 aft cabin with 454's. Can't for the life of me find anything on fuel consumption rates on that model. I assume with a hull speed of about 8.5 knots according to the formula, that would be the sweet spot for fuel efficiency, but then I've seen one reference where it's designed to "cruise" at about 14 knots, whatever that means. We cruise the Carver 32 at 1200 rpm and around 7 knots for 1.6 miles per gallon, but I can't any fuel burn info on that Mainship...anybody know?
 
What Kulas said. I've got 350 horse Crusaders with about 1600 hours. Equipped with AFBs and HEI. Still strong, pretty quite (all things considered), and ultra-reliable. At 8-9 knots, about 8-10 GPH. Of course, this is a planing hull so I'm not sure about the comparability to a displacement hull. She will do an honest 25+ kts by GPS, but the fuel burn at that speed is breathtaking. So, I don't do 25 kts often.
 
>I assume with a hull speed of about 8.5 knots according to the formula, that would be the sweet spot for fuel efficiency, but then I've seen one reference where it's designed to "cruise" at about 14 knots, whatever that means.<

Hull speed = Sq Rt lwl (SL) times 1.34 or so is not an efficient long range displacement cruise speed.

It is how fast a boat can go before requiring 4x or more power to attempt to climb up on the bow wave.

Displacement cruise is SL x .9 to 1.15 or so, which is usually 1/2 to 1/3 the fuel burn of > 1.34 Hull Speed<

>I've seen one reference where it's designed to "cruise" at about 14 knots,<

That is probably as slow as you can go and maintain control and not without falling off the plane.

You might only burn .75 GPM instead of over 1 GPM at higher speeds.
 
Last edited:

Latest posts

Back
Top Bottom