SD75I vs. SD70I

[Anonymous]

looking at Canadian National's SD70I's and SD75I's, is there any way to tell them apart visually?

[Anonymous]

SD75 is a few feet longer (2 feet I think)

[Anonymous]

Also look at the long hood end of the SD-70I, there should be a set of ditch lights on the gangway. These are not on the SD75I's.

[Anonymous]

I may be wrong on this since I didn't look it up before posting, but I think the 75 has two blower ducts, one on each side, that are smaller than the one duct on the 70

[Anonymous]

Visually I am still thinking about. Internally, there are some definite differences.
1. SD70 runs at 900rpm throttle 8 vs SD75 runs at 950rpm throttle 8.
2. SD70 uses mechanical fuel injector vs SD75 uses electronic fuel injector.

[oltmannd]

Whoa! A 710 engine at 950 RPM! Scary thought. The 645 didn't make out too well @ 950 RPM and the 710 has a one inch longer stroke - lots and lots of piston speed and high forces from reciprocating mass (which go up with speed squared?) Wonder how they're holding up?

-Don

[Anonymous]

Maybe why the SD75 isn't very well thought of?

[Anonymous]

Wow, somebody out there actually knows about the relation between stroke/RPM/and piston speed. Don you've just impressed me!

[oltmannd]

Maybe all my parents $$ for my engineering education didn't go to waste!