Quadrajet Problem Solving > Dialing in your rebuilt Quadrajet carburetor

“Cliffs Notes” First Recipe to Full first recipe

<< < (2/2)

theraymondguy:
Thanks for the words and a chuckle.  I’m stuck with the 5.0L unless a windfall finds me and provides better accommodation than my current one car garage.  I’ve been meaning to spend an afternoon at the junkyard hunting a crack free set of Vortec heads, they’ll need to be decked regardless and perhaps I can pick up a little compression.

As far as my q jet parts list, maybe just the tapered primary rods and finish the remainder of the first recipe (sans secondary rods and hanger) until such time as the heads are done?

Cliff Ruggles:
Vortec heads are NOT a bargain for SBC builds.  They are paper thin and will crack if you stare at them too long!

The require a "custom" or special intake manifold which costs more money, and they lack screw in studs and guide plates so you have to buy self centering rocker arms which is another additional cost.

They also lack a heat crossover since the later Vortec engines used a dry intake.  All wet flow systems require a heated intake for best efficiency and I don't care what all the resident "experts" tell you about blocking off the heat crossovers to make more power, that's another regurgitated statement we see all over the NET that just passes on more poor advice.

IF you lived down by the equator you'd probably be OK with a cold intake.  Even up here they will eventually warm up anyhow, but all you do is cost yourself efficiency till some heat gets in it. 

I've had quite a few customers try the Vortec heads on later SBC's because they are dirt cheap compared to far superior aftermarket heads like World Products SR's and they are fine until the temps get cool/cold outside.  Then the phone rings off the hook and they are complaining about hesitation/stumble/bog, surging at light engine load and asking me about buying different jets and rods to fatten things up so they can effectively plow snow in Wisconsin or run around the Mountains of Colorado on their hunting trips. 

I even had one customer rig up a coolant hose system to heat his aluminum Vortec intake because thing worked very poorly in the cold Winters in the Rocky Mountains where he uses the truck......FWIW....

Mudsport96:
What are the "G" codes on your rpo list? It is also possible that your rear gear ratio is causing the car to be sluggish in the lower revs. An 85 fbody could have had anything from a 2.73 to a 3.42 gear 3.73s were possible with higher option cars. And no amount of tuning will really help if you have 2.73s and a 305.

lightning boy:
I agree, up the compression. Keep in mind 305's make good torque, but they are RPM limited due to the small bore size. I think the factory tuned port motors made 200hp.

Navigation

[0] Message Index

[*] Previous page