Worse GPH port side

Richey rich

Active Member
Sep 23, 2012
393
Lake St Clair
Boat Info
2010 Sea Ray 450 SunDancer
Engines
Twin 480 Cummins w/Zeus pods
B7261F52-A71D-4D96-9F0B-F5E738F49839.jpeg
46F356A2-9B55-4831-B470-519DC25B37F4.jpeg
F719D371-3358-4216-ABE8-214AEC3F6471.jpeg
Hey guys. Wonder if someone can help me with this. Here is what I’m experiencing on my port side. Let me preface this by saying this is on a 2010 450 sundancer with Cummins 4800 and Zeus pods.

port side…..
-Intake temp higher 10 degrees
-Boost psi is higher by 1.5psi
-Gear pressure higher by 8 psi
-% load is 4% higher even though throttle is the same
-gallons per hour is .8 worse.
 
What are your tabs set at?
 
What are your tabs set at?
i took these pictures before our last conversation about the AUTO TABS, so this was taken while in auto... i did not take a pic of where each tab was set. the fuel economy is not really the main concern, wondered about all the other data as a whole.
 
I get differing load (and as a result all the other info different between engines )when I am not trimmed the same.

Maybe start with all else being equal and take new pics of the data?
Need to try and eliminate other sources of the variance.
 
I get differing load (and as a result all the other info different between engines )when I am not trimmed the same.

Maybe start with all else being equal and take new pics of the data?
Need to try and eliminate other sources of the variance.
Fair enough. I will do that and update information I find. Thanks
 
I get differing load (and as a result all the other info different between engines )when I am not trimmed the same.

Maybe start with all else being equal and take new pics of the data?
Need to try and eliminate other sources of the variance.
Took the boat out for a run and collected new data. This time I made sure tabs were same.
96AB7781-08E2-4D4B-9A39-24B61172A775.jpeg
F1B383A5-E7B1-4A2E-9EC3-19A01D0DA080.jpeg
B6282BA1-A7ED-4687-A581-A2CCE5A0857D.jpeg
1AB9795F-1001-41B0-90DB-1133B39FEBDE.jpeg
C24684B4-EFC4-493C-AF77-43F35BC3EF67.jpeg
 
So in sync to achieve the same RPM my port side has 4% more load than the starboard which in turn is giving it more boost…? So should I take them out of sync put the same load on both motors and compare boost then? Why would one motor require more load to achieve same RPM?
Yes @Shaps these are my engines



are these your engines?
https://www.touron-nautica.com/descargas/CMD/curva/QSB5_9/480.pdf


I'm not familiar w the specifics of your motors but first pass i think your boost is low.

At same load, how different is the boost between them?
Throttle % not the same as load.
 
Last edited:
outside some small variation, i would expect both motors to work equally hard to achieve same output.
Agree with you something is up. I still think your boost is low.
I would do 2 things:
1. Start simple:
Air cleaners are cleaned and oiled?
Breather elements clear (they're cheap enough if they have not been changed on your watch)
Racors clean? What does the tattletale needle say on the gauge on them?

2. i'd give a call to the guys at seaboard (sbmar.com). Walk them through what you have done and see what they suggest.


Im sure there are some diesel cognoscente who can add here
 
View attachment 109911 View attachment 109912 View attachment 109913 Hey guys. Wonder if someone can help me with this. Here is what I’m experiencing on my port side. Let me preface this by saying this is on a 2010 450 sundancer with Cummins 4800 and Zeus pods.

port side…..
-Intake temp higher 10 degrees
-Boost psi is higher by 1.5psi
-Gear pressure higher by 8 psi
-% load is 4% higher even though throttle is the same
-gallons per hour is .8 worse.
Did you by any chance hit anything while running? I have in the past hit a log and even though everything appeared to be ok from that point on when i filled the fuel tanks 1 side would take 20 gallons more thank the other. Prior to that every top off was within 1 gallon. Sent the props out and had them scanned and the one that hit the log was way out of speck. Repaired and put back on and back to normal.
 
Did you by any chance hit anything while running? I have in the past hit a log and even though everything appeared to be ok from that point on when i filled the fuel tanks 1 side would take 20 gallons more thank the other. Prior to that every top off was within 1 gallon. Sent the props out and had them scanned and the one that hit the log was way out of speck. Repaired and put back on and back to normal.
Interesting. I don’t think I have hit anything but this has been going on all season and I just got the boat. This fall maybe I’ll send them out and see. I have duo props on each pod.
 
Not saying it isn't worthwhile to send the props out but pretty sure you would feel a vibration if the props were that out of whack.
 
Not saying it isn't worthwhile to send the props out but pretty sure you would feel a vibration if the props were that out of whack.
Definitely no vibration in props. Once I am able to get load the same (not throttle) the boost is very close to same and so is MPG....
 
I know this isn't something you'll want to hear but I think it's normal. My port engine burns approx 1gph more than starboard and ALWAYS has. I have Cummins 480CE's.
 
I know this isn't something you'll want to hear but I think it's normal. My port engine burns approx 1gph more than starboard and ALWAYS has. I have Cummins 480CE's.
So after messing around with it a bit on a longer trip this weekend. If I keep the load the same and tabs the same, I burn almost the same gph, and almost same boost within 0.3. But, that being said. I don’t run that way normally so I guess it just is what it is.
 
Sounds like you proved out your motors are performing pretty close to same. I'd call that a good result. Well done @riche
 

Forum statistics

Threads
112,950
Messages
1,422,878
Members
60,932
Latest member
juliediane
Back
Top