Timing Curve on 360 in an RV

[Mattax]

What I want to know is how much performance and mpg was sacrificed for lower emissions ? And how can I recurve mine to recover both ?

What are you starting with?

It varied with year and appliction.
The earlier years (66-70ish) the sacrifice was mostly at idle, and relatively small.
Somewhere after that, the sacrifices increased - the worst in my opinion being the vacuum advance to crcutch the lack of mechanical and the pupose built delays - which were really annoying.
The cats actually helped in some ways because with them a more normal timing curve could be used. But that took some time to redevelop.
The straight sixes seem to have taken a bigger hit in performance than the v-8s. The 318s were pretty efficient and clean from the get go. The hi-po engines obviously were tougher to run clean at idle and lowest rpms. JMHO

 

[mbaird]

I have the 78 440-1.
I will compare the curve to the passenger car curve for 78. I think I have a FSM for 78 pass.

 

[Mattax]

I have the 78 440-1.
I will compare the curve to the passenger car curve for 78. I think I have a FSM for 78 pass.

With a 440 we can also compare with pre-emissions big block timing of both low compression and high compression/perfromance cammed engines.