Quadrajet Questions
03-22-2002, 12:15 AM
#11
BEACH PARTY
Platinum Member
Jafo,
The problem is that there is no heated air going through the Vortec manifold and head (the port in the head for the exhaust crossover is cast shut). The manifold never reaches a high enough temperature to cause the choke to open and there is no pad or well to attach the stove.
With mine I removed all of the pieces that were part of the choke assembly. There is no shaft or butterfly assembly. I worked with the jetting, metering rods, and power valve spring to get the carb spot-on. With precise tuning you can get the engine to run without the choke... mine did. To warm it up I kick the idle up just a bit while loading her up. By the time everyone is on the boat and gear/food and drinks are stowed she's ready to go. She'll take off dead cold as well but I usually let her warm up before leaving the dock. The point is that you can tune the Q-Jet to work very well. It shouldn't be too hard to dial in. Just pick up all the jets and metering rods that you can afford (they are cheap).
Tom
The problem is that there is no heated air going through the Vortec manifold and head (the port in the head for the exhaust crossover is cast shut). The manifold never reaches a high enough temperature to cause the choke to open and there is no pad or well to attach the stove.
With mine I removed all of the pieces that were part of the choke assembly. There is no shaft or butterfly assembly. I worked with the jetting, metering rods, and power valve spring to get the carb spot-on. With precise tuning you can get the engine to run without the choke... mine did. To warm it up I kick the idle up just a bit while loading her up. By the time everyone is on the boat and gear/food and drinks are stowed she's ready to go. She'll take off dead cold as well but I usually let her warm up before leaving the dock. The point is that you can tune the Q-Jet to work very well. It shouldn't be too hard to dial in. Just pick up all the jets and metering rods that you can afford (they are cheap).
Tom
Charter Member
03-22-2002, 07:41 AM
#13
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Location: Beautiful Lake St. Clair,MI
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jafo and TomZ gave some good information. Do pick up Dennis Moores book. The full Q-jet tuning kit from Edelbrock can be purchased for about $100.00 give or take. It is much more expensive to buy individual rod sets from a GM dealer.
You will also find that the choke will not be much of an issue. Try operating the boat without the choke before you invest in anything else. Most likely with some warm up time it will be fine.
I think the Q-Jet is a good choice for moderate HP engines. Low speed operation is great, fuel consumption at cruise is good and top end power is good. You will not have to change the primary side of the carb much if at all. There is a guy in my area that only works on Q-Jets. His company is Q-jet Specialists. If you want any info on him e-mail me.
Good Luck.
You will also find that the choke will not be much of an issue. Try operating the boat without the choke before you invest in anything else. Most likely with some warm up time it will be fine.
I think the Q-Jet is a good choice for moderate HP engines. Low speed operation is great, fuel consumption at cruise is good and top end power is good. You will not have to change the primary side of the carb much if at all. There is a guy in my area that only works on Q-Jets. His company is Q-jet Specialists. If you want any info on him e-mail me.
Good Luck.
