- Joined
- Feb 18, 2003
- RO Number
- 11165
- Messages
- 82
Finally! After the mechanic had the engine for 100 days from removal to replacement, I have my newly rebuilt 454 Mercruiser in the boat. I picked the boat up today.
I have read and printed out George's engine breakin proceedure (great reading if you qualify for engine break-in.)
My engine builder's instructions differ from George's in one major area. George says, "Avoid operating in the 2000-3000 RPM range at all times during the 10 hour break-in period"
My engine builder's instructions were as follows:
"Avoid Idol Speed below 1500 for 10 hours. Run at variable speed between 1500 rpm and 2800 rpm for the first 10 hours. Do not let the 4 barrel open or exceed 2800 rpm during the first 10 hours. Change the oil at 10 hours then operate normally."
I ran the first hour between 1500 and 2000 today. the second hour between 2000 and 2700.
My boat comes up on plane at around 2600 to 2700 rpm. Normal cruising speed is 2900 rpm, 18 to 19 knots.
Operating above 2000 and below 2500 has the boat fighting to come up on plane (it's the most inefficient speed, unless the water depth is 6 feet or less , the boat will not plane in that range.)
Above 2800 rpm contradicts the engine builder's instructions, but my normal operating range is 2900 to 3200.
Fuel consumption climbs to "rediculious" above 3300 rpm" and I rarely run in that range.
Any suggestions on how I should spend the next 8 hours of engine break-in?
I have read and printed out George's engine breakin proceedure (great reading if you qualify for engine break-in.)
My engine builder's instructions differ from George's in one major area. George says, "Avoid operating in the 2000-3000 RPM range at all times during the 10 hour break-in period"
My engine builder's instructions were as follows:
"Avoid Idol Speed below 1500 for 10 hours. Run at variable speed between 1500 rpm and 2800 rpm for the first 10 hours. Do not let the 4 barrel open or exceed 2800 rpm during the first 10 hours. Change the oil at 10 hours then operate normally."
I ran the first hour between 1500 and 2000 today. the second hour between 2000 and 2700.
My boat comes up on plane at around 2600 to 2700 rpm. Normal cruising speed is 2900 rpm, 18 to 19 knots.
Operating above 2000 and below 2500 has the boat fighting to come up on plane (it's the most inefficient speed, unless the water depth is 6 feet or less , the boat will not plane in that range.)
Above 2800 rpm contradicts the engine builder's instructions, but my normal operating range is 2900 to 3200.
Fuel consumption climbs to "rediculious" above 3300 rpm" and I rarely run in that range.
Any suggestions on how I should spend the next 8 hours of engine break-in?