[Capt J]

What operating temperature are other Captains seeing on their Detroit Diesels when running in gear at 600 and 800rpm's (without running at cruise first). Please state temperature, engine model (ie 8v71TI) and boat model.

[Pascal]

mines (8V71Ns) will get to operating temp (170deg or so) at 800 RPM in gear from a cold start.

[Marmot]

165 to 180

8v71 8v71TI 12v92

[Seafarer]

~170-180 clutched in.

8v71NA

[riptidecrew1939]

I have a pair of 671's in my 53' Elco. They run between 160 - 180 at cruising speed 12 knots, 1750 rpm.

[K1W1]

Hi,

I have manage to find a Detroit Diesel Service Manual from 1975 that gives a Normal Operating Temp Range for the engines as 160 to 185 Deg F.

[mariog]

our 8-71ti's run at about 160 in gear at idle. too low a temperature for proper combustion IMHO...

[K1W1]

Originally Posted by mariog

our 8-71ti's run at about 160 in gear at idle. too low a temperature for proper combustion IMHO...

Hi,

Not according to published Detroit literature it aint.

[Capt J]

Originally Posted by K1W1

Hi,

Not according to published Detroit literature it aint.

I've seen a lot of Detroits run at 140 degrees at idle, some run at 160 degrees, none of the ones I've ran (1,000's of them) have made 180 degrees under 1,000 rpms. According to modern Detroit literature they recommend running at 180 degrees, and in the latter years all came with 180 degree thermostats. They also recommend oil changes at 200hrs now instead of every 100hrs.

I too feel they run a little dirty and rich on fuel at 160 degrees. At 180 degrees they seem to burn the fuel a little better (mechanical injectors), and the DDEC two stroke motors all ran at 180 degrees and actually run very nice. The DDEC's had a lot of low end torque and ran similar to a modern cat C series across the rpm range. Unfortunately they didn't install all that many DDEC series in yachts.