Grey Marine 671 age

[rbsharpe]

I am attempting to determine the age of a pair of Grey Marine 671 engines. On the starboard side of the engine blocks I found the following numbers.
Port: 65 over 5152825-R over CSC
Stbd: 45 over 5111434 over CFD
The owner believes they are 1978 engines but I don't believe they were manufactured as Grey Marine engines at that time. They are installed in an LCM(3) also of unknown age. The vessel has the hull number of C-52443 welded into the main beam in the engine room. I have been told that this number means the vessel was the 524th LCM (3) built in 1943 but have no documentation on this either.

Any information would be appreciated.

[Çemberci]

information is available on this page.
http://www.engine-cemberci.com/engine/GRAYMARINE/GRAYMARINE.HTM
and also
http://www.boatdesign.net/forums/showthread.php?t=19070
oktay çemberci

[rbsharpe]

Thanks, this is interesting information. What I am looking for is information on the Grey Marine 671 that became the detroit diesel 671.

[Çemberci]

We have these informations
http://www.engine-cemberci.com/engine/DETROIT/10.pdf
http://www.engine-cemberci.com/engine/DETROIT/4.pdf
Oktay çemberci

[FAST FRED]

You have it backwards , the Detroit Co built the first 6-71 in about 1938.

They produced them by the thousands during WWII for trucks , tanks , gen sets, and boats.

The Grey co marinized the 6-71 in a variety of configurations for the military , and later for civilian boat use.

With the serial numbers ANY Detroit Dealer will be able to order parts.

A copy of Boats & Harbors will offer a variety of suppliers at far less cost than DD.

FF

[FAST FRED]

To locate the serial numbers for DD'

http://www.powerlinecomponents.com/literature/detroit_diesel/v71_model_chart.htm

FF

[hartley]

re 6-71 serial numbers and model numbers and date of manufacture ,model numbers can tell you a lot but serial numbers are what is required to ascertain date of build and for ordering parts .
the numbers quoted by rbsharpe are unfortunately not serial numbers from a
6-71 diesel ,either a earlier model general motors diesel up to 1970 or later model detroit diesel.are you sure the numbers quoted are not casting numbers ?.serial numbers are stamped on the block on blower side just below the cylinder head joint .
you can be sure that if they were built after about 1947 they would not be grey marine ,for about this time grey were sold to continental motors ,and grey marinization of general motors diesels ceased
the serial numbers should be like this ...6Axxxx 4 digits up to about 1965 or
6Axxxxx 5 digits after 1965

a typical number could be 6Axxxxx
RC
6=no of cylinders
A=all standard accessories
R=right hand rotation
C=right hand blower(looking from rear) ......left hand water rail........left hand exhaust,other configurations could be RA RB RD LA LB LC LD
all very confusing ,hope this is of interest to rbsharpe......cheers hartley

[rbsharpe]

Thanks, this is very helpful information. the numbers quoted were cast in the block proud of the surface on the right lower central side of the block. I'll check on the location you describe for additional numbers.

R. Sharpe

[hartley]

re 6-71 engine serials
sorry i made a mistake in my example of engine numbers ....should read
5 digits up to about 1965 and 6 digits thereafter....cheers hartley

[pascal bertram]

looks like you know a lot about detroit diesel marine engine;
could you please give me the exact model and le power rating of those engines
671 (1062-4310) serial number 6A287260 port and 6A287354 strb

one thaousand thanks i look everywhere and my bad tecnical english dont help me, kind regards

pascal coldefy
pascoldefy@hotmail.com

[hartley]

Pascal Following might be some help 6A just means 6-71 engines .your range of serial numbers denote build 1974----1975.
The number 1062-4310 denotes
1=71 series engine
06 = number of cylinders
2 = marine engine
4 = basic engine arrangement
3= turbocharged engine
10= specific model number
re power output hard to say seeing they are in a 42 bertram they would have to be uprated probably by a firm called Johnson and towers ,also there was another firm involved ,I cannot think of the name of the top of my head
anyway j and t engines were rated up to 450 hp I have even heard of 475 hp
all this depended on injector size,blower speeds ,turbo boost etc etc
there should be a plate affixed to valve cover which would tell you,if plate is missing ,most have been souvinered ,you would have to contact johnson and
towers in the states with you info ,they are still in business
cheers.....hartley

[dmuck]

Hello folks: I find this site very interesting. I have a 1947 671 Gray Marine engine out in my yard under a tarp. It has been there for a very long time. I have some related perts such as an injector rail, a starter solenoid, a mechanical tach, the engine has a 3 to 1 Twin Disc manual gear and I have an extra trans case and some gears out back under an old boat mold. I am looking to rid myself of this stuff now that I am to old to think I am going to complete all of the projects I had in mind back then. I also have a Twin Disc manual for this old trans. The Gray Marine is fresh water cooled. Does any of this equipment have any value? I also have a couple Continental four cyl. diesel engines which would be good only for cores at this point. Thanks Don

[FAST FRED]

Just put an add in Boats & Harbors and one of the local lobster boat guys will come to you.

These old DD are superbly reliable , and tho the new (1938 was a long time ago) engines will do better at fuel use and are lighter, some guys like to get home EVERY TIME!

FF

[dmuck]

Thank you for your input fast Fred. Don