I was wondering what RPM a mercruiser 5.7L EFI engine with a roller cam and vortec heads should run at for cruising and top end.This is installed in a 24' grady white offshore.
2007-08-21 06:04:26 · 4 answers · asked by robert h 2 in Cars & Transportation ➔ Boats & Boating
That engine is designed to run 4600-4800 rpm at WOT. If it won't reach that rpm, and the engine is running properly, then you are over propped. You need to take some pitch out. Your optimum cruise should be at about 75% of WOT.
2007-08-21 18:33:40 · answer #1 · answered by Campo 4 · 0⤊ 0⤋
I have this engine minus the cool heads and rollar cam...just spoke with my local marine shop--who reports that all props are designed to be tested at wide open throttle...
I was told to take the boat out on a calm day, open her up and you want her to run around 4800 RPM @ full-throttle-with the correct pitch prop.
2007-08-21 18:35:14 · answer #2 · answered by casinoreverend 3 · 0⤊ 0⤋
Since you have put a roller cam than you will need to know what cam was installed an power curve to find out what the rpm should be???
2007-08-21 13:52:45 · answer #3 · answered by 45 auto 7 · 0⤊ 0⤋
AT CRUISING SPEED - 2400 RPM TO 3400 RPM. BEST FUEL USAGE. AT TOP END 4200 TO 4800 RPM.MAX. 4400 RPM WOULD BE BEST FOR LIFE OF THE ENGINE. OVER REV AND ENGINE WILL NOT LAST.
2007-08-21 13:17:32 · answer #4 · answered by FILE 4 · 1⤊ 0⤋