Reply
 
Thread Tools Search this Thread Display Modes
 
Old 11-10-2019, 05:34 PM   #1
Senior Member
 
City: Hilton Head Island
Country: United States
Join Date: May 2018
Posts: 138
Difference between Cummins Engines

I am looking at two 2005 boats. One has a 6BTA5.9 370hp Cummins engine and the other has a QSB5.9 380 hp. Aside from the extra 10 hp, are these two engines essentially the same in term of set up and performance? Is one more or less rugged than the other?
__________________
Advertisement

Mark P is offline   Reply With Quote
Old 11-10-2019, 05:35 PM   #2
Senior Member
 
City: Rochester, NY
Country: USA
Vessel Name: Hour Glass
Vessel Model: Chris Craft Catalina 381
Join Date: Aug 2019
Posts: 465
The QSB is the slightly newer version of the 6BTA. So 1 generation newer with EFI instead of mechanical injection. The QSB will run cleaner and is quieter, but performance wise they should be similar.
__________________

rslifkin is offline   Reply With Quote
Old 11-10-2019, 05:41 PM   #3
Senior Member
 
City: Hilton Head Island
Country: United States
Join Date: May 2018
Posts: 138
Should I assume that fuel consumption would be comparable, or is EFI measurably better?
Mark P is offline   Reply With Quote
Old 11-10-2019, 05:46 PM   #4
Senior Member
 
City: Rochester, NY
Country: USA
Vessel Name: Hour Glass
Vessel Model: Chris Craft Catalina 381
Join Date: Aug 2019
Posts: 465
Looking at the fuel curves published by Cummins, I'd say the QSB might have a slight efficiency advantage, but nothing significant. They don't look drastically different or anything.
rslifkin is offline   Reply With Quote
Old 11-10-2019, 06:15 PM   #5
Guru
 
Comodave's Avatar
 
City: Au Gres, MI
Country: US
Vessel Name: Never Say Never
Vessel Model: President 41 DC
Join Date: Jul 2015
Posts: 5,770
The QSB should be a bit more efficient but it also comes with electronics on the engine which may or may not be good, depending on your preference.
__________________
Boat Nut:
If you are one there is no explanation necessary.
If you aren’t one, there is no explanation possible.
Comodave is offline   Reply With Quote
Old 11-10-2019, 06:18 PM   #6
Senior Member
 
City: Hilton Head Island
Country: United States
Join Date: May 2018
Posts: 138
Good info. Thx
Mark P is offline   Reply With Quote
Old 11-10-2019, 06:47 PM   #7
Senior Member
 
City: Hilton Head Island
Country: United States
Join Date: May 2018
Posts: 138
Comodave - can u give me some insight on preferences? Since these boats are both singles the number 1 preference for us is reliability assuming similar maintenance. What are the preferences folks have one over the other?
Mark P is offline   Reply With Quote
Old 11-10-2019, 06:53 PM   #8
Guru
 
Comodave's Avatar
 
City: Au Gres, MI
Country: US
Vessel Name: Never Say Never
Vessel Model: President 41 DC
Join Date: Jul 2015
Posts: 5,770
Personally I really don’t have a preference however my engines are all mechanical. We were coming home and we blew a fuse on one of them and didn’t find out until after we had docked and went to start that engine and it wouldn’t start due to no power, but it kept running until we had shut it down. However some people love the electronic engines, more efficiently, more information about how the engine is running, etc. i guess that the electronic engines need more specialized training and equipment to work on them. Good and bad...
__________________
Boat Nut:
If you are one there is no explanation necessary.
If you aren’t one, there is no explanation possible.
Comodave is offline   Reply With Quote
Old 11-10-2019, 08:07 PM   #9
Member
 
Turning Point's Avatar
 
City: Anacortes
Country: USA
Vessel Name: Turning Point
Vessel Model: 67’ Ed Monk Pilothouse Trawler
Join Date: Aug 2019
Posts: 24
Quote:
Originally Posted by Comodave View Post
Personally I really don’t have a preference however my engines are all mechanical. We were coming home and we blew a fuse on one of them and didn’t find out until after we had docked and went to start that engine and it wouldn’t start due to no power, but it kept running until we had shut it down. However some people love the electronic engines, more efficiently, more information about how the engine is running, etc. i guess that the electronic engines need more specialized training and equipment to work on them. Good and bad...
Comodave,
Do you have 6bt mechanical injection? Mine have an electric fuel solenoid that must have power or they won’t run. Occasionally I’ve tried to find a part number for a “normally open” solenoid so they would continue to operate in a ‘black ship’ situation but so far no luck.
Thx
Duncan
Turning Point is online now   Reply With Quote
Old 11-10-2019, 08:21 PM   #10
Arc
Senior Member
 
City: Long island
Country: U S
Vessel Name: Riverwind
Vessel Model: Eastern
Join Date: Aug 2018
Posts: 104
QSB is 0 smoke on startup. I started mine yesterday 33 Deg. , no smoke.
The Db level is also lower. Although they have some sensors , if they fail the engine is not going to stop. I have never had a failure. Priming the fuel system is simply turning the key. Both engines will give you long life and low maintenance. I think if you run both , the Qsb is more friendly.
Arc is offline   Reply With Quote
Old 11-10-2019, 08:27 PM   #11
Guru
 
Comodave's Avatar
 
City: Au Gres, MI
Country: US
Vessel Name: Never Say Never
Vessel Model: President 41 DC
Join Date: Jul 2015
Posts: 5,770
I have Lehmans.
__________________
Boat Nut:
If you are one there is no explanation necessary.
If you aren’t one, there is no explanation possible.
Comodave is offline   Reply With Quote
Old 11-10-2019, 10:22 PM   #12
Member
 
City: Long Beach
Country: USA
Join Date: Dec 2018
Posts: 22
I had an electrical problem that cut power to the solenoid on an old 6BT. Used safety wire to hold it open and continued on. KISS Keep it simple stupid. I love the old pre-emissions engines. There are fewer things that can fail.
__________________
Jim Nance
T210DRVR is online now   Reply With Quote
Old 11-10-2019, 10:47 PM   #13
Member
 
Turning Point's Avatar
 
City: Anacortes
Country: USA
Vessel Name: Turning Point
Vessel Model: 67’ Ed Monk Pilothouse Trawler
Join Date: Aug 2019
Posts: 24
Quote:
Originally Posted by T210DRVR View Post
I had an electrical problem that cut power to the solenoid on an old 6BT. Used safety wire to hold it open and continued on. KISS Keep it simple stupid. I love the old pre-emissions engines. There are fewer things that can fail.
Hi Jim,
My fuel solenoids are internal and inline, no moving parts to wire open.
There is a mechanical fuel cut off on the fuel injection pump but that would involve both disabling the solenoid and attaching an external solenoid to pull the cut off lever.

Duncan
Turning Point is online now   Reply With Quote
Old 11-10-2019, 11:52 PM   #14
Guru
 
Alaskan Sea-Duction's Avatar
 
City: Inside Passage Summer/Columbia River Winter
Country: USA
Vessel Name: Alaskan Sea-Duction
Vessel Model: 1988 M/Y Camargue YachtFisher
Join Date: Jul 2012
Posts: 4,811
Something not mentioned here is the difference between to two for regular maintenance stuff, i.e. oil and fuel filters.

With all of today's electronics, its nice to be able to tie your engines to all the electronic world. Full enclosure, I have 3208 T/As mechanical.
Alaskan Sea-Duction is offline   Reply With Quote
Old 11-11-2019, 02:34 AM   #15
Guru
 
North Baltic sea's Avatar
 
Country: Finland
Vessel Model: Nordic Tug 37
Join Date: Sep 2015
Posts: 917
Hi, I have so far only good experiences QSB 380hp machine, it is a quieter, more fuel efficient and the best I can drive it low+ 800 rmp for long periods of time without worrying about the glass transition and coal (I have asked this thing Cummins factory) At the moment I have 1500 hours of which + 1000 in a few years.


I have read Seaboard Forum Tony A one checked the charter boat with engines of about +17,000 hours without any major problems.


The only thing I replaced with the machine is the raw water pump sherwood, I replaced the Sea max with a longer service interval.


Normal maintenance is made easy, eg changing the fuel filter, since venting can only be done by turning the key, the electric pump does the job.


NBs
North Baltic sea is offline   Reply With Quote
Old 11-11-2019, 06:45 AM   #16
Guru
 
ranger42c's Avatar
 
City: Maryland
Country: USA
Vessel Model: 42' Sportfish
Join Date: Aug 2013
Posts: 4,656
We have Cummins 6CTAs, and I tink I'd slightly prefer the newer electronic QSCs... but that's partly because I'd like to be able easily get more real-time engine data presented. I guess the horsepower increase is larger than with the BTA to QSB series, and that'd also be decent for our type boat.

But I like what we've got, too.

-Chris
__________________

__________________
South River, Chesapeake Bay
ranger42c is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 05:55 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012
×