ffdjm wrote:The brochure "Nissan Diesel SD22 Engine" is available on my very temporary ftp server ftp://137.229.80.21/technology as two 18 MB pdf files.
Thanks, Douglas. I'm mirroring them here:
Nissan Diesel SD22 Engine for Automotive & Industrial Use (PDF page 1) (PDF page 2)
The brochure author makes clear these general specs are for INDUSTRIAL SD22s. So these specs do not address liberties Nissan took with "automotive" production engines starting in 1981 models.
Interesting are the torque curves, horsepower curves, and upper RPM limits for each of the three
classifications. Clearly the "automotive" SD22 is expected to be the most athletic, hence the PISTON improvement in 1981 road vehicles.
A sincere thanks to Douglas for sharing this brochure.
-Philip Passed 08May2008
My friend, you are missed . . .
1982 Datsun 720KC SD-22
asavage wrote:But I'm sure it feels more like 6 HP
Seriously, if the displacement went up over 10%, why didn't the HP go up over 10% (6 HP).
Al, well actually it did increase over the 6 HP mark. The SD22 is listed at making 61 HP @ 4000 RPM. The bigger SD25 was listed at 70 HP @ 4000 RPM. So, Nissan jumped the horsepower up 9 and that's pretty good. Oh and the torque rating for the SD25 was 114 FT LBS @ 2000 RPM. This is all according to a factory Nissan ad I have that covers the Nissan 720 circa 1983. Hey, if you happen to turbocharge an SD25 you might be able to make 85-95 HP without much trouble. I'd like to find out that's for sure.
Salvy
1982 Datsun Maxima diesel wagon w/ 228k miles
*occasional daily driver*
1982 Datsun Maxima diesel sedan w/ 252k miles
*now off the road as a parts car and sent to the yard *
asavage wrote:But I'm sure it feels more like 6 HP
Seriously, if the displacement went up over 10%, why didn't the HP go up over 10% (6 HP).
Al, well actually it did increase over the 6 HP mark. The SD22 is listed at making 61 HP @ 4000 RPM. The bigger SD25 was listed at 70 HP @ 4000 RPM. SNIP Salvy
The FSM lists "advertised HP" so ... as long as all comparisons use "advertised HP" and identically equipped engines then ... the data is somewhat useful. However, SAE net HP is always lower and more reliable.
SAE vs. Advertised HP Advertised Horsepower
Surprise! Those horsepower numbers presented in advertising and brochures aren't always accurate. Though manufacturers are supposed to base their horsepower ratings on SAE net standards, they are not completely beholden to it. They often fudge the numbers. Ford and Mazda both recently got in trouble with the Mustang Cobra and the MX-5 Miata, respectively, when they delivered a car that had less horsepower than what they advertised. Ford ended up doing considerable warranty work to bring the numbers up where they belonged, and Mazda re-rated their car and offered to buy back any offended customers' cars. General Motors regularly underrates their engines, most notably the GM LS1 5.7L engine as installed in the F-body (Camaro and Firebird) cars. Mechanically almost identical to the engines installed in the Y-body car (Corvette), the engine mysteriously "lost" 40 advertised horsepower in the F-body chassis. Although this technically is as fraudulent as selling a car with less than the advertised horsepower, no one seems to complain when they get a car with more horsepower than what appears on the spec sheet.
SAE Net Horspower
In 1972, American manufacturers phased in SAE net horsepower. This is the standard on which current American ratings are based. This rating is measured at the flywheel, on an engine dyno, but the engine is tested with all accessories installed, including a full exhaust system, all pumps, the alternator, the starter, and emissions controls. Both SAE net and SAE gross horsepower test procedures are documented in Society of Automotive Engineers standard J1349. Because SAE net is so common, this is the standard we will use to compare all others.
To the above list I would add variations such as air throttled Bosch inline pump vs. the unthrottled Bosch VE pump, CA vs 49 State injection timing, EGR, and P/S.
-Philip Passed 08May2008
My friend, you are missed . . .
1982 Datsun 720KC SD-22
*