What are your 455 quadrajet jets/rods & Secondary rods?
July 21st, 2009, 11:37 PM
#1
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Join Date: May 2009
Location: Northern California
Posts: 1,643
What are your 455 quadrajet jets/rods & Secondary rods?
All,
Just breaking in a rebuilt 455 in my 66 98 convertible. Mondello built it with the 18-20 cam more or less stock except for roller tip rockers & porting the intake manifold to match long ago ported heads. New crank, rods & pistons. Sadly I have no documentation on compression ratio, exactly what parts, etc. Gotta follow up on that for posterity... Or sanity.
So I have an 800 cfm qjet on there with a nice red cap HEI & Accel plugs of some variety, big ol 9mm wires and most eveything fresh. I'm trying to dial in the qjet to match a fairly tight, but theoretically high flow ( + mebbe high rpm) motor.
Part of the Mondello deal was to have SMI (Sean Murphy Induction) rebuild my qjet. They did a fine job with new throttle plate bushings & new bits here & there along with nice recoloring. They even did the cobra jet 4 hole drill job in the secondary fuel tubes. Cool. Only trick they didn't do (I have to assume by choice) was the poncho style cutouts in the secondary airvalve. But hey, I have a dremel. No biggie.
Anyway SME sent out the carb really rich: 75 jets, 60 rods, a "K" hanger and DA secondary rods. Really rich. I assume they did that to keep me from burning valves. Or maybe they & Mondello didn't communicate. I dialed it back to 73 jets, 53 primary rods, "K" hanger and BH secondary rods to lean it out on the primary and richen the secondary a bit. The motor runs very cool. Maybe even cold. I couldn't get it up to 180 tonight on a 65 degree evening on the freeway.
My setting is richer than the usual factory 69-71 jets, 48 or so rods, some mid-range hanger and AU secondary rods. But then those settings are for 750 cfm qjets from 66-71 or so, not an 800 with ported heads & factory duals...
I'm moving the right direction, but I'd like a few examples of how you all have done your qjets to limit the search space.
Long winded way of saying what primary jets, rods, secondary hanger are you using in your qjet (particularly you 800 cfm people)?
Thanks in advance.
cf
Just breaking in a rebuilt 455 in my 66 98 convertible. Mondello built it with the 18-20 cam more or less stock except for roller tip rockers & porting the intake manifold to match long ago ported heads. New crank, rods & pistons. Sadly I have no documentation on compression ratio, exactly what parts, etc. Gotta follow up on that for posterity... Or sanity.
So I have an 800 cfm qjet on there with a nice red cap HEI & Accel plugs of some variety, big ol 9mm wires and most eveything fresh. I'm trying to dial in the qjet to match a fairly tight, but theoretically high flow ( + mebbe high rpm) motor.
Part of the Mondello deal was to have SMI (Sean Murphy Induction) rebuild my qjet. They did a fine job with new throttle plate bushings & new bits here & there along with nice recoloring. They even did the cobra jet 4 hole drill job in the secondary fuel tubes. Cool. Only trick they didn't do (I have to assume by choice) was the poncho style cutouts in the secondary airvalve. But hey, I have a dremel. No biggie.
Anyway SME sent out the carb really rich: 75 jets, 60 rods, a "K" hanger and DA secondary rods. Really rich. I assume they did that to keep me from burning valves. Or maybe they & Mondello didn't communicate. I dialed it back to 73 jets, 53 primary rods, "K" hanger and BH secondary rods to lean it out on the primary and richen the secondary a bit. The motor runs very cool. Maybe even cold. I couldn't get it up to 180 tonight on a 65 degree evening on the freeway.
My setting is richer than the usual factory 69-71 jets, 48 or so rods, some mid-range hanger and AU secondary rods. But then those settings are for 750 cfm qjets from 66-71 or so, not an 800 with ported heads & factory duals...
I'm moving the right direction, but I'd like a few examples of how you all have done your qjets to limit the search space.
Long winded way of saying what primary jets, rods, secondary hanger are you using in your qjet (particularly you 800 cfm people)?
Thanks in advance.
cf
July 22nd, 2009, 12:10 AM
#2
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Join Date: Oct 2004
Location: Southern CA
Posts: 2,212
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