Cummins 4B

[EdithMarie]

Hey folks, a newbie here with his first diesel inboard. She's a Cummins 4B non-turbo, dry stack and keel cooled, with 4000 or so hours and a velvet drive transmission. Survey doesn't have much on the to-do list outside of servicing. Anything in particular I should look for with these engines during spring commissioning outside the usual fluids n filters n belts etc? Seems like a solid low hp workboat motor, but I don't have any experience with them...I'd be grateful to hear from those folks who have run em. Thanks!

 

[Genius]

Hey folks, a newbie here with his first diesel inboard. She's a Cummins 4B non-turbo, dry stack and keel cooled, with 4000 or so hours and a velvet drive transmission. Survey doesn't have much on the to-do list outside of servicing. Anything in particular I should look for with these engines during spring commissioning outside the usual fluids n filters n belts etc? Seems like a solid low hp workboat motor, but I don't have any experience with them...I'd be grateful to hear from those folks who have run em. Thanks!

That engine may be pretty hard on that velvet drive. Best to keep it loaded up and RPM on the high side vs low speed idling. The input shaft gets beat up, especially with a 4 cylinder.

Only thing with the engine I know of is the belt tensioner. You can read more about that on Sbmar.com. Clean fuel, and you are good to go.

 

[EdithMarie]

Much obliged, will check out that link

 

[PatriciaLynn]

That engine at that rating should run a LOOOOONG time. 20,000hrs should be doable. As has been mentioned above, idling around is the enemy. Run it loaded up and you are good to go.

 

[EdithMarie]

Glad to hear! I was assuming it would go 10k+ on hours, but no actual experience to back that assumption up...appreciate the input!

 

[captjohn]

I know they vibrate "a bit", I'd check out the engine mounts, for wear. But that engine will probably outlive you!

 

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The 4B is good but does shake alot. Like mentioned above keep an eye on the vibration isolators and look at any place red dust shows up. That shows that something needs to be tightened. Happens on my 6B where the expansion tank bolts to the support bracket.
That's a good setup and parts for both are cheap and easy to get.

 

[EdithMarie]

Appreciate you, and wilco!