Looking for a little advice on the timing numbers I just pulled from my 73’ Duster (backfire issue)
And of course someone has to muddy the waters.
Chrysler was correct and once again your 'fact' that Chrysler used manifold vacuum connection lacks the key points as to why. In particular, it was due to more heat being put into cylinder walls to produce a more complete burning of left over hydrocarbons and to reduce CO. This was done for improved emissions purposes. The drawbacks were more energy is converted to heat and increased engine temperatures. On the rare occasions the coolant temperature becomes excessive the temperature controlled override connects comes into action.
When Chrysler wrote 'complete combustion' it was essential true for the purposes of explaining why and how to check timing. They wisely did not spend the time going over the differences of chemically perfect combustion versus most mechanically efficient combustion, or flow bench stuff, shapes of combustion chambers, quench, pulsing and reversion, harmonics, entry shape, fuel composition, or any of the other factors that go into 'complete combustions.
Complete combustion in that paragraph of the 1969 Ignition MTSC was in reference to the previous sections explaining the purpose of centrifical advance and vacuum advance.
I'll post them here so the context clear, and makes a complete picture (pun intended)
And of course someone has to muddy the waters.
Chrysler was correct and once again your 'fact' that Chrysler used manifold vacuum connection lacks the key points as to why. In particular, it was due to more heat being put into cylinder walls to produce a more complete burning of left over hydrocarbons and to reduce CO. This was done for improved emissions purposes. The drawbacks were more energy is converted to heat and increased engine temperatures. On the rare occasions the coolant temperature becomes excessive the temperature controlled override connects comes into action.
When Chrysler wrote 'complete combustion' it was essential true for the purposes of explaining why and how to check timing. They wisely did not spend the time going over the differences of chemically perfect combustion versus most mechanically efficient combustion, or flow bench stuff, shapes of combustion chambers, quench, pulsing and reversion, harmonics, entry shape, fuel composition, or any of the other factors that go into 'complete combustions.
Complete combustion in that paragraph of the 1969 Ignition MTSC was in reference to the previous sections explaining the purpose of centrifical advance and vacuum advance.
I'll post them here so the context clear, and makes a complete picture (pun intended)