Logo
FULL SITE MENU

Gen IV merc 454

3

350

New member
I am going on a 110 mile trip with my 34 foot express. It has twin 454's. Is it safe to run them at cruising speed (approx. 3200 rpm's) for the length of the journey or should I vary my speeds throughout. I'm not so concerned with fuel economy as I am for the safety of the engines.
 
If the engines have been maintained and aren't brand new, you shouldn't have any issues with short trip like that....
 
3200 is only about the 1/2 power setting. Overheating won't be an issue with a healthy 454 gen IV at that setting, assuming your WOT is over 4k. I've done 4 to 5 hour stretches at 3200 with no breaks and 20 year old blocks. I did a 165 nm run once with a 440 engined boat with no breaks at 20 kts. And, that's not setting any records.
 
If you regularly run at that speed I wouldn't think twice about it. However, if you normally run much slower you may see some issues like slowly rising temps or fuel issues. A "good run" is the best thing for your engines. The first hour should tell the tale. Stop after that check the oil & take a look around the engines. Look at the stuffing box. If all is well carry on. I would carry some extra gas filters and know how to change them at sea.
 
Back
Top