Grey Marine 671 age

and if its a two valve or a four valve it has a twin disc clutch 1.5/1 gear ratio.

Pull the valve cover and look at the number of valves.

A 2 valve engine will have 3 rocker arms , one is for the injector pump.

The 4 valve will have a bridge plate so one rocker can work 2 valves.

The WWII military DD 6-71 student instruction book will be very useful. Find it on line .

It covers all models , and gives power ratings.

The biggest difference is in WWII the oil changes were at 50 hours , today this can easily be raised to 150 , but you MUST MUST only use CFII rated 40 wt oil.

Shell Rotella T 40 wt still carries the required CFII rating.

 

Thanks fred I will check. This motor has been in a crate in storage for about 30 years but still has all the factory lube and fogging. Is there anything I check before I put power to the starter to see if it turns over

 

"all the factory lube and fogging. "

An engine is storage will have special (and very expensive) storage oil, not lube oil as an operating engine would require.

To just crank the engine to watch it spin , a few seconds , no problem.

But before operation new CF II SAE 40 oil should be installed.

IF you live where it regularly gets cold a block heater would be my first purchase.

These fit into the cooling jacket , cost under $100 and with the engine out should take 1/2 hour to install, if that.

hen you finally start it the factory fogging oil will take 5 min of AMAZING amounts of smoke to burn out. Will kill the mosquitoes a couple of towns away.

For the first start I would use a small tank ABOVE the engine , so priming is simply removing the bleed screw on the engine mounted filter.

AS a precaution with the valve cover removed , operate the throttle and observe the rack lift and close ALL the injectors.

Should one stick it will make the engine hit runaway rpm , not nice for a brand new engine.

I would also change the oil after the first 25 hours , as machining was not as good as today , where almost no break in is the norm.

FF

 

Thanks for the advice

 

I always clamp a pair of vice grip pliers on the injector rack and use it for a throttle. If it runs away, it is easier to shut down.

 

I'm deep in a research project on-line for a client here in Berlin looking
for spare parts / manuals for a Detroit Diesel 6-71 ( and /or 6071 A ) for a
yacht restoration project...

klink-krueger.de/

http://www.boote-magazin.de/test_te...meister/a32759/fotostrecke/540917/494679.html

"Looking for Shop and repair manuals [German ed. woud be of interest];

and spare/replacement parts sources for Detroit Diesel 6-71 (also 6071 A)

A source in the EU would be a bonus for our restoration project."

any quick ideas?

 

The modern repair manuals are available from DD for your engine ., or used on line.

These are for written the mechanic who finished a factory DD course, not a boat owner.

Many good pictures and rebuild techniques.

My suggestion is based on the concept that these engines are sadly getting older and rarer and more BASIC info is required to maintain them.

For any DD 6-71 the best book I know of is

" Grey Marine Students Manual" in the 3rd or later edition.

During the 1940's Grey built the DD engines for the US military and this was their Naval instruction book.

It can be found on line for $50- $75 bucks.

The students manual is great reading and explains all the 6-71 in very simple terms , both daily maint and rebuilding.

Good hunting.

 

the G.M. 6071-A Marine Version is the 'target'

The G.M. 6071-A from the 1960's [1955? to 1970?] is the 'target' motor...

I'm uncertain, as the search narrows, if it is radically differ from the GRAYMARINE period motors... thoughts?

Any specific URL's?

I find a lot for Truck/Bus, none for "marinized" version(s)

 

I have a crate gray marine 6/72 for sale if you are looking

 

The joy of the 6-71 is its versatility , blower on either side , engine rotation either direction , change is just a few gaskets.

The truck, genset , industrial use or boat engines are basically ALL the same.

The difference is mostly what is bolted on the engine , generator head pump, marine tranny truck tranny , your choice.

ALL will operate at their rating for very long periods of time (many thousands of hours) and limiting the RPM to 1800 will add to that considerably.

The simplest way to view a DD (and most diesels) is they will consume a certain amount of fuel , before a rebuild.


Grey marine built their DD 6-71 engines mostly for the US Navy , so most you find will have fresh water cooling and a marine tranny.

Their DD is identical to every other DD in terms of parts and operation.

The truck, bus parts will fit .