Twin volvo 3.0 engines not running the same

[sergio marti]

Hello.
I've got 2 volvo 3.0GLP-J 2007 engines installed in my boat, and my problem is that they aren't running the same at WOT, one is about 4500rpm while the other doesnt arrive to 4200, that problem has been since new but never took importance.
Has anybody twin installations and have similar problem?
thanks

 

[Haffiman]

Re: Twin volvo 3.0 engines not running the same

Twins never do!
It might be the engines, it might be the tachs, it might be the wiring harness.
Start by checking with a separate tach directly at the engines to see if it is an engine performance difference or an indicator difference.
To get them run 'in pair', you would normally need fully electronic engine control (EMM) and a synchronizer.
If running L and R props, even a slight difference in the props may have an impact.
Everything have tolerances, and the further in the opposite end of the tolerances the engines, props etc are, the bigger the difference.
Even the engines itself have an output tolerance from factory.
You may have one 'strong' and one 'weak', but still within the tolerance.