Would opening the secondaries more make it so that I can back those out to 1 or 1.5 turns or should I just leave it as is?
u need to adjust adjust the secondaries while the car is running.. how to in old posts search for 90 deg rivet...
its a matter of adjust the sec , then adjust the mixtures and idle speed.. It these are going the right way for the 1 1/2 turns in idle speed and mixture screws.. keep going, if not go the other way....only 1/4 turn on the sec adjust max at a time til u get down to about 1/16th on secondaries
Caution DO NOT have the secondaries fully closed against the bores.. u wil wear butterfly bushes , possibly bend them, and damage the carb bores
If u cant get to the 1/2 turn tolerance then u have the wrong carb for the job , or most likely a vaccuum leak somewhere
Think about it, the gap in the secondaries is a built in vaccuum leak...
If I were to lower my timing any more I would have a tough time getting it to idle.
bigger the cam the more inefficient the engine is at low rpms...because the inlet and exhaust are open too long and the engine cant devaple compression....but this can be over come by incresaing the idle advance.
on non lean burn egr engine one uses manifold vaccuum on the VA.
The idle is made up of the intial +VA so the VA must be all in at the idle vaccuum..
to dial in the idle .....
dial in means to establish what the idle advance should be in therory...
dump the VA and block off...
now adjust the intial , secondaries, mixtures and idle speed so everything is in spec with the [B]lowest intial for a reasonably stable idle.. if want a little lumpy a little less advance.. but stable...
Now what u have in the intial is what u NEED for your idle advance, which will be made up of the VA on manifold vacuum, and fully actuate at the idle engie speed plus the intial.
The dial in establish the total.. no VA start with a total of about 36/ 37 degs, do 3 runs over a measured distance and time them
knock the total back a couple degs and repeat, till withing acouple degree the time will suddenly increase.. car slower..
What the total was before the time increased ,, is now your dialed in total (intial+cent)
Since u now know
the required idle.advance and your idle vacuum
The total advance
it just a matter of juggling the amount of degs in the VA and the amount of degs in the cent and keep the all up.. intial+_cent +VA under 40 /42 degs.
BUT to do it right u also need the AFRs in the ball park with a ball park timing ready set up.
carb idle circuits around mid 14s to mid 15s
WoT around the 11.5 to 12.5 no higher
And cruise circuit about the same as the idle