How much for a '79 Cordoba on BAT?

[saforwardlook]

(Highjack) What's your experience with the 360-2 engine? It was introduced in 1971 and, on paper at least, marked its highest hp and torque ratings in 1974 and 1975. What kind of development was going in those years and how did they keep the ratings steady in 1975, the first year of the catalytic converter?

Those engines still had the richer air/fuel calibrations of the past in 1974/75 although they did start to have retarded spark advance curves at moderate loads. Full throttle air/fuel ratios and spark curves still were robust. The Lean Burn systems were introduced in the 1976 models and that is when the lean air/fuel ratios really took hold even at WOT throttle as well as retarded spark curves and were present on the Federal 2 bbl models. Emission tests are run on dynamometers only under part throttle conditions. In 1977, emission standards dropped again and that is when drivability and performance really took a tumble.

When the catalytic converters were introduced in 1975, neither Ford nor Chrysler engineers had any clue to actually know how to take advantage of them to lower emissions. GM did, however, since they helped develop them in concert with Engelhard and Johnson Matthey Corporations so they knew how to take advantage of them out the gate in 1975. GM knew that they could keep robust air/fuel ratios and good spark advance curves and let the catalytic converters do most of the emission clean up work while both Ford and Chrysler still relied on lean air fuel ratios and retarded timing to lower emissions.

I actually went out and rented some GM vehicles back in 1975 because I did competitive vehicle driveability evaluations and took vehicles to and from work each day to evaluate them. GM vehicles were excellent while Ford and Chrysler vehicles were awful: full of stumbles, poor performance, pass outs cold and engine surging at steady speeds. I and my staff took the initiative to actually take parts off the GM cars and had the carburetors flow tested to determine where they were setting their fuel/air mixtures and distributors to see where they were setting their spark curves and that is when the light bulbs turned on. We figured out just what GM was doing to maintain good performance/drivability while letting the catalytic converters do most of the work and implemented what we learned into the later 318/360-4bbl engines. The other calibration/emissions guys didn't take the initiative to see how other manufacturers' vehicles performed so they just did the same ole/same ole.

 

[PeugFra]

You just solved a mystery for me, thanks!

 

[commando1]

I dunno Stan.................in the late 70s the 360-4 bbl engines performed flawlessly while the 400s/440s still had lean calibrations and associated poor drivability and performance. The 360-4s were back to richer stoichiometric fuel/air mixtures, not lean and vacuum advance was restored in the calibrations. I and my staff were the ones that were given the assignment to "fix" the 318 and 360 4-bbl engines at that time by the chief engineer, Dick Goodwillie - and that is how we did it for both the federal and California calibrations. The 360-4s actually felt stronger in acceleration than the 440s because they had richer air/fuel mixtures and higher stall torque converters and healthy spark advance whereas the 440s ran too lean with retarded timing that yielded weak output and low stall converters that felt doggy and just guzzled more gas.

I and my staff made the catalytic converters do the emission clean up, not some stupid lean calibration/retarded ignition timing crap. We were also able to increase just a little of the exhaust gas recirculation to help in reducing nitrogen oxide emissions since the rich air/fuel ratios covered up the small increase in exhaust gas recirculation in terms of drivability and performance.

Just an aside, it was the combination of hydrocarbons and nitrogen oxides in the vehicle exhaust that reacted in the presence of sunlight, thus creating the dreaded "smog", that was especially strong in California.

Also Stan, the lighter weight of the LA engines helped the overall balance of the B bodies such that the handling, especially of the Magnum GT models, was improved over what use of a B/RB engine would yield.

Can't deny the science, I guess.