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| Gray Marine 6cyl w/ pneumatic starter... |
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Message |
    
Kevin Hinman
New member
Username: brumby
Post Number: 1
Registered: 06-2012
| | Posted on Wednesday, June 27, 2012 - 02:20 am: | 
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What is the sufficient starting air pressure & cfm�s for a 6 cyl Gray Marine engine with a pneumatic starter?
We�ve just acquired a 1942 Stephens Tug with a six cylinder diesel & pneumatic starter. My good friend Roy, who is an exceptional mechanic, and I are going thru the engine and looking forward to seeing if she will run. She has not been run in 9 years but had run well at that time 9 years ago. She simply wasn�t run by her new owners for nine years � no reason. We drained the fuel lines and hooked up the motor off a fresh fuel container to be sure she gets good clean diesel. We have also inspected the oil and cooling system along with the pumps and impellers.
The pneumatic starter is engaging very well though it seems the pressure is not sufficient for the motor. The original compressor had been replaced at some point with a 110v simple 1hp 2 gallon compressor which slowly fills a larger 5ft x 18� pressure tank. We intend on replacing this compressor with a higher cfm better compressor and see if that makes a difference.
So far she sounds good and our confidence is that she�s going to run.
Any insight into the nuances of the Gray Marine 6 cyl engine would be greatly appreciated.
Thx
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brumby
New member
Username: brumby
Post Number: 2
Registered: 06-2012
| | Posted on Wednesday, June 27, 2012 - 02:31 am: |
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Oops!
Please move this post to the Deisel inboards discussion.
Thank you |
Charles Holmes
Member
Username: jimmys
Post Number: 26
Registered: 01-2011
| | Posted on Wednesday, June 27, 2012 - 01:49 pm: |
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Kevin,..Sounds like you have a Detroit GM Diesel 64HN9 WW11 Inline 6 Cyl. Diesel Engine, that will perform well for you if you do a couple things before you try to start it:
1. Get your Air Pressure up to 120lbs in the Air Tank,..which sounds like you are already doing.
2. Really important is Priming the Fuel System in the Engine injectors,..Getting a Hand or Electric Primer Pump and hook it to the IN on the Secondary Fuel Filter, presurizing the Unit Injectors in the head. You can remove the Fuel Return line on the Cylinder Head to see the Fuel Returning/flowing through the Injectors,..priming them, making sure you have fuel flow. There is a R80 Restricted Fitting on the Head to maintain the fuel rail pressure.
3. Also make sure your Primary and Secondary Fuel filters are full of Fuel.
Now you are ready to start your Jimmy!!
Good Luck! |
Charles Holmes
Member
Username: jimmys
Post Number: 27
Registered: 01-2011
| | Posted on Wednesday, June 27, 2012 - 01:56 pm: |
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Kevin,..
Also I reccomend since your engine has been sitting for 9 years,..I suggest that you remove the Valve Cover and manually move the Injector Control Rack, back and forth,..making sure each Injector is not stuck into full fuel. By doing this you will free some injectors that may be partialy stuck, or find one that is really stuck and needs to be replaced. If you start the engine with a stuck injector, the engine will run away and cause damage. A run-away engine is very hard to stop! |
brumby
New member
Username: brumby
Post Number: 3
Registered: 06-2012
| | Posted on Thursday, June 28, 2012 - 03:37 am: |
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Thx Charles,
Sounds exactly where Roy & I were headed. We did removed the valve cover the first day and jostled the injectors prior to starting. We considered that an simple 8psi fuel pump might help on the fuel line off the pony tank to get things going. As mentioned ... I don't think the little compressor was getting the tank up to 120psi. We will try a larger compressor the next go round. Thank you very much for your advice ... greatly appreciated. |
brumby
Member
Username: brumby
Post Number: 4
Registered: 06-2012
| | Posted on Thursday, June 28, 2012 - 03:49 am: |
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On another note ... anyone with knowledge of any of the twenty Stephens tugs built for the Army Corp in the 1940's please chime in. Quite a few people would love to here of the history of these beautiful vessels... myself especially. I have not been able to locate any of the others or determine any ill fate of any of them. I've been scouring the net trying to dig up their whereabouts or tales of woe. Hoping to find news articles or anything regarding their history. |
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