Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - Carb set up help.
View Single Post
  #21 (permalink)  
Old 11-04-2012, 02:01 PM
F-BIRD'88's Avatar
F-BIRD'88 F-BIRD'88 is online now
Yada Yada Yada
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,210
Wiki Edits: 0

Thanks: 5
Thanked 388 Times in 382 Posts
When I had that same cam in my 10 year old +60 over 350 vortec motor it ran very very well
great performance great daily driver good on gas etc etc etc..
The thing would not click off a 12sec et thou. 13.01 13.02 13.00 13.04 @104.5 105MPH No matter what I did it just did not want to give me a 12sec time slip. But it ran real good. 4.10's 3500 stall. 10:1cr.

Found out only later that the mechanical fuel pump (130gph rated) was in fact limiting the cars top end performance.... fuel flow.carb starved. I have since corrected the problem and ditched the inconsistant mech fuel pump.
It became immediately evident once the 406 motor went in. (it's near 500hp)

This fuel issue at the time also limited my ported 305Ho head testing too meaning the ported 305HO heads were working even better than my testing indicated but the stupid fuel system limited it.
That race 350 w/305 heads, big solid cam and 12.65:1cr combo flew even with the fuel flow limitation.
That was a low buck weapon. Never got to the nitrous on that one. (because I knew there was a issue with the fuel system on the car but had not nailed it down yet.. it would come and go.)

There is a 12 sec ET in your car...

Power valve with that cam will not be that critical it will be a fine tuning element controling when the carb switches from cruise AFR to power AFR as you get into the throttle 4.5", 6.5" 10.5",,, vacuum gauge,, afr meter
and drive testing.. The power valve opening point does not effect WOT tuning or power. When you rug it, the power valve immediatly opens.
The power valve should stay closed at idle. (idle manifold vacuum, in gear) not an issue with that mild cam.

Do not confuse part throttle cruise wher the carb is on the idle off idle transition,,, with higher road speed cruise when the carb is on the primary main jets. Many people get this wrong and mess with the main jets when the problem is the idle circuit transition. The idle and off idle circuit is ubber critical.

70 to 74 pri and 80 to 85sec jets all all just fine for this carb on the RPM manifold on your motor.

Last edited by F-BIRD'88; 11-04-2012 at 02:22 PM.
Reply With Quote