[quote=mshaw230
The old carb was 26 seconds, so I'm 5 seconds faster. With this carb and the retarded timing (2 btdc) leaner mixture was also 26 seconds. Maybe if I go 10 btdc, it'll drop to 20.
For the breather, the original intake has a metal screen. I see Tom Lowe's offy valve cover with a couple of breathers venting to engine compartment. Thoughts? Mark [/quote]
On my moms 73 Nova, I would adjust the timing with as much advance as the engine could take, just as long as it would not detonate.
That adjustment alone made the biggest improvement on acceleration & much better mileage.
We used to take my moms cars to garage/maintenance shops for tune ups, all they would do is set the timing to factory specs, change plugs, rotor, cap, plug wires.
This 73 Nova used to be our family travel car.
Best mileage it ever got was 16 MPG.
After I started working on the Nova, (being 16 & it was the car I was going to drive, wanted a bit more power) adjusting the timing by advance it, the mileage went to 18 MPG, just by the timing adjustment alone.
Don't try & set the timing to factory settings, those settings were made so the car can pass emissions, lower timing burns more of the unburned gas increases combustion chamber temps.
Make sure the mechanical advance is working, @ least install a spring kit into the distributer. It helps.
I always hated hooking up the valve cover breather into the air cleaner assy, the blow by would prematurely get the air filter dirty.
Toms breather assy's look like they should work. They have a labyrinth inside to reduce the chance oil from escaping.
MBHD
