Cat 3126 sugggested RPM

[swtava]

I just took the keys on a 1997 Sea Ray Express Bridge with twin Cat 3126 TA's. They have 1200 hours and tested out good with oil chemical test. Sound great too! What is the suggested RPM cruising speed? What is the suggested "high end" cruising speed? What should I expect to burn for fuel per hour per engine?
Thanks, Scott

 

[endless seas]

On our 450da I run them between 2100-2350 for a very efficient cruise.depending on conditions I'm averaging between 18.5 to 23 combined.
Not bad for a 45.

 

[HUMPH]

I just took the keys on a 1997 Sea Ray Express Bridge with twin Cat 3126 TA's. They have 1200 hours and tested out good with oil chemical test. Sound great too! What is the suggested RPM cruising speed? What is the suggested "high end" cruising speed? What should I expect to burn for fuel per hour per engine?
Thanks, Scott

What horsepower are your engines?

 

[markrinker]

I just took the keys on a 1997 Sea Ray Express Bridge with twin Cat 3126 TA's. They have 1200 hours and tested out good with oil chemical test. Sound great too! What is the suggested RPM cruising speed? What is the suggested "high end" cruising speed? What should I expect to burn for fuel per hour per engine?
Thanks, Scott

Refer to your specific applications Owners Manual that came with the boat. Cruise RPM for 3126/385hp in my 2000 410DA is ~2300. That makes about ~28mph with smooth conditions, ~28 gallons per hour.

 

[JC3]

Endless is right on the numbers. I pull it back a little at about 2000 rpm cruise about 18-20 knots depending on sea conditions etc... I have begun to trawler some. Two reasons for this, as i get older the trip means more than how fast i get there and money is tighter (Daughter in college). Doing my last trip on the 450 this spring. I am very, very sad about this, but it is what it is. Good luck with your boat, JC

 

[fwebster]

Caterpillar says the wot speed is 2800 rpm, the max recommended sustained cruise speed is 2400 rpm, but, as the others said, you will find a sweet spot down around 2200-2300 where the engines just loaf along and seem to be "happy".

 

[carterchapman]

2250 gives me 20 kts.

 

[endless seas]

My horsepower is 420.

 

[aquadancer]

My 3126TAs are 350HP. For longer cruising I like to be at 2150 rpm which gives me around 19 kts. No speed records will be set but I'm not looking for any. At that rpm everything sounds "right" to me and fuel burn is very reasonable (vs. my old 370DA with 7.4 as engines). I should note that we usually cruise pretty heavy with a large dinghy, full water, full gear, etc

 

[MikeM]

I've got a 2001 400DB, with the same 3126/350hp versions. Nice motors! My first foray into the world of diesel... I recall reading that normal cruise range for this engine is 1700 to 2400 RPM, Max RPM at WOT should be 2800. If I'm not in a hurry, I usually cruise AT 1800-1900 RPM If a quicker pace is desired, I'll set 2400...