QSC 12v-24v conversion

[Luke Nelson]

Hi All,

 I am looking at a pair of QSC 540hp engines. They look to be 12V engines but my vessel is wired 24v. Other than the Starter, Alternator , lift pump   is there anything else?

It has smart craft V1 displays listed as 12v on back. The anologue instruments are VDO/ Smartcraft rpm  and would need swapping or  run 2 smart craft displays for the engines and no analogue?

The inter-phase box is pn#4929690 SW V 3.3.

Next one.

 They have sat for 6 years. What checks short of a full dyno should be done? They have almost no oil in them, coolant levels are good. The consensus is they were full checked and one maybe both were dyno tested after a major works but then the owner died and no one can really find out what the report said.

 

 Thanks Luke

 

 

Topic

[Corey Schmidt]

ZF Solenoids

You will need to choose the solenoids that match whatever system voltage you will be supplying… if your Glendinning is setup for 24V then your solenoids must also be 24V.

[Luke Nelson]

Next 12-24v question.

Once the engines are converted to 24v does the 24-12v convertor  feeding the smartcraft control the gear shift in 12V?  The EEC3 is a Cummins Mercruiser  one and ask for 12v so I assume the solenoids are 12v?

 

 Does this sound right or will I need 24v solenoids?

 

thanks Luke

 

 

[Rob Schepis]

Indoor Storage for 6 Years

Ok, good to hear they were stored in the shop.  So the “environment” should basically be a non-issue.  In addition to the usual fresh fluids, clean fuel, impellers and belts I would prelube the engines via the main oil gallery with new oil at between 10-20 PSI for 20-30 minutes and bar them over by hand.  Also sounds like an ideal time for installing Wolverine pan heaters and making your first startup a “warm start”.

[Luke Nelson]

Thanks Corey,

I was concerned about bowing up the Smart craft stuff. I found the 24-12 article and was working on it being opposite.

regards Luke

 

[Corey Schmidt]

SmartCraft

Luke, the SmartCraft systems on the Cummins engines are all 12V… you will need a DC/DC converter that connects to the 40-pin “Medusa” harness that will take your 24V and step it down to 12V for the SmartCraft system (ECM, displays, etc.)

Understanding your SmartCraft 1.0 “Medusa” Vessel Adapter Harness

The components you’ll need to change out to 24V are as follows:

• Starter
• Alternator
• Lift pump
• Mag Switch (Start Solenoid)

Hope that helps…

[Luke Nelson]

Hi Rob,

 Sat on a shop floor. Both have had a repaint  since they came out of the vessel so there is not much to see from the outside.

 

 The next step may be to pull the injectors and put a borescope down to look at the bores  for rust marks where the pistons have sat?

 

[Rob Schepis]

“Sat for 6 years”…. outside in a boat or on a shop floor?  Pictures would allow us all to see what you are looking at…..

[Author]

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