06-29-2012, 10:08 AM | #1 |
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buying rebuilt q-jet
has anyone bought a reman quadrajet from Summit......any comments on product or service? I'm shopping around, any other vendor recommendations?...I have no core to rebuild, wouldn't want to do it myself anyway, and want to find the best rebuilt I can. need a q-jet for '66 manifold, need iron base, divorced choke.
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06-29-2012, 11:11 AM | #2 |
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Re: buying rebuilt q-jet
I bought one from these guys and just installed it on the 350 in my 64 C10 last weekend. It runs mint. I highly recommend.
http://www.smicarburetor.com/ Mine has electric choke and I installed it on a factory cast iron 1969 Q-Jet intake. The electric choke is a nioce upgrade. |
06-29-2012, 04:55 PM | #3 | |
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Re: buying rebuilt q-jet
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I am somewhat confused, the PO of this manifold told me I definitely need to find an IRON BASE quadrajet......I'm not that knowlegeable about this stuff, but Sean Murpey (SMIcarburators) just told me they never made a Q-jet with an iron base. anybody enlighten me on this iron base issue? this manifold has a chanel grooved all the way across the carb deck, in front of the (much smaller) primarys. are they all like this? Last edited by 63burban4x4; 06-29-2012 at 05:04 PM. |
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06-29-2012, 05:38 PM | #4 |
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Re: buying rebuilt q-jet
All Q-jets have alum. base. Often they are confused with the prediseser. It was fased out in 65 & was a 4GC called a 4 jet.
(i lost my spelling corrector.) |
06-29-2012, 11:10 PM | #5 |
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Re: buying rebuilt q-jet
Dont get a stage 1 carb unless you have a built engine. If it is stock then get the stock carb.
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06-30-2012, 05:35 AM | #6 |
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Re: buying rebuilt q-jet
Actually, Sean Murphey himself recommended I use the stage 1 carb
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06-30-2012, 10:48 AM | #7 |
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Re: buying rebuilt q-jet
a friend of mine did that and he regreted it. Maybe he got a bad brand new carb but he could not get his engine to run good with it.
In the end the choice is yours, all we can do is tell you the stories. Maybe it will work for you.
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06-30-2012, 11:24 AM | #8 |
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Re: buying rebuilt q-jet
Take it from someone who knows the Q jet , it is a great carb , and if you will learn how to change jets (not as easy as a holley ) you can really make a great performer as well as a great milage carb out of it ...I had 73 chevy truck when i attended tech school ,and the truck had a 4gc rochester on it ,it got 8 mpg .. I started playing with Qjets (building them with no choke etc. cause I was a punk kid ) and checked my milage each week to and from school .. and found that when I richened the primarys up to 74 jets I got 12 mpg .. It had 68 jets from the factory .... soon after that I figured out how to switch it from manual choke to electric and believe me i had a steady stream of customers to my door... really the Qjet is a great carb ... on a side note when I was at tech school ,they had a cutaway of a variable venturi carb that GM designed , it got better milage that the Qjet but it cost 7.00 more to manufacture so they canned it in favor of the Qjet.....
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06-30-2012, 11:27 AM | #9 | |
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Re: buying rebuilt q-jet
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If MikeN is happy with his carb, I'm guessing it's probably a stage 1, it's the lowest level Murphey sells, closest to stock, and the one he himself recommended to me. MikeN, is that right? Fleetside, Did you say your unhappy friend bought his from SMI? Sounds like that'd be one vote for and one vote against..... |
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06-30-2012, 11:45 AM | #10 |
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Re: buying rebuilt q-jet
one piece of dirt can render a great carb into a smoking pile of crap....... anyone that is in the carb business can tell you the return rate is high on rebuilt carbs, 90 percent of it is installer error...........
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06-30-2012, 02:17 PM | #11 |
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Re: buying rebuilt q-jet
he bought it new through Summit.
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06-30-2012, 04:02 PM | #12 |
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Re: buying rebuilt q-jet
the stage 1 carb sold by summit appears to be a Jet. I've heard plenty bad about Jet, already planned to stay away.
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06-30-2012, 05:27 PM | #13 |
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Re: buying rebuilt q-jet
I've been looking around today, and my best guess is that the "stage 1" carb rebuilt by Jet, sold by Summit, and the "stage 1, stage 2 or stage 3" carbs sold by SMI are describing different things. Summit also sells the SUM201210, which appears to be the more stock carb, just don't know who rebuilds these for them? is it also Jet? I haven't heard good things.
the "lowest level" carb on SMI's website is called the "stage 1" and is recommended for towing and RV apps. stage 2 is recommended for motors with modifications such as headers, cams. Sean Murphey recommended his "stage 1" for my truck. I'm still curious as to some details of MikeN's experience....is that a SMI stage 1 that you're happy with, and what sort of mods does the motor it's running it on have, if any? Last edited by 63burban4x4; 06-30-2012 at 05:36 PM. |
06-30-2012, 10:51 PM | #14 | |
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Re: buying rebuilt q-jet
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As they mention there, that setup tends to put a lot of heat up under the carb (not really a good thing). I've used the trick they mentioned there about plugging those two holes with pipe plugs. That leaves the lower exhaust crossover passage open so the choke will work, but blocks the exhaust flow from going directly up under the carb. Also you'll want a pre-71 4MV style Q-Jet in order to work correctly with the style of choke coil that fits the choke well on that manifold. The newer 4MV Q-Jets have a different choke mechanism that needs a different choke coil that won't fit the older intake manifolds. Regarding the iron base, I agree with Wrenchbender Ret about someone getting things mixed up with the Rochester 4GC. Those carbs did have an iron base but most of them had equally sized primary & secondary bores. Some versions did have slightly larger secondaries but no where near as large as the Q-Jets. And like Wrenchbender Ret said, those 4GC's were being phased out in 65 with Q-Jets taking their place. However, some truck applications continued to use the 4G (manual choke version of the 4GC) for a couple more years. |
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07-01-2012, 06:42 AM | #15 |
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Re: buying rebuilt q-jet
Thanks, Ray. Now, THERE'S some info I can use, it's the best I've found yet, and it makes all the pieces fit. Only difference between the info in that thread, and what I have been told already by the PO, is that he swears that around 65 or 66, they did make a Qjet with an iron base, he may be wrong about that, but EVERYTHING else he told me was spot on. Since then,, I have gotten lots of conflicting info .......must be as many different opinions about q-jets, as there are Q-jets!! LOL. He did tell me it was ALL about using the correct base when you use THIS manifold, (which does have the "smiley" chanel you describe). The PO had actually suggested tapping and plugging those ports, as well. He insists that this manifold can work fine, it just needs to be done correctly. Sounds like he's right about that.
I suppose I could use a different manifold, however, one thing I definitely NEED is the front oil filler, which really narrows down the field of available manifolds. Now that i know what to look for, I think I'll stay with this. One last question (it's probably adressed in that cvette thread, I didn't finish reading it yet)..... do you believe that it's a bad idea (is it even possible?) to go to an electric choke, when using this manifold? (The choke spring sits down into a "well" on this manifold, not on a flat pad). I do have a heat riser (mechanical- original '64 ramhorns) that I planned to still use.....and also left the crossover ports in the intake gaskets OPEN, not blocked off. Is this best? Thanks again for sharing yer expertise! Ed |
07-02-2012, 07:33 PM | #16 | |||
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Re: buying rebuilt q-jet
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But on the other hand, I find those intake manifold mounted choke thermostats to be more in tune with the actual engine temperature than an electric choke that has a tendency to cool off quicker. |
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07-03-2012, 06:22 AM | #17 | |
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Re: buying rebuilt q-jet
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Again, thanks, I'm confident now that I understand the situation, and should be able to find what I need. I never got into carbs much, but I've had numerous Q-jets over the years, and can honestly say they've always been fine. Only problem I can ever remember, I bought a new 85 K10, and the carb gave us some trouble with worn shafts, but not till about 250K miles, and it outlasted the first motor, made it onto the replacement Goodwrench at about 175K. I guess I'll take that any day! And, it might seem silly, but I'm really trying to keep a very stock look under the hood, ('cept the engine color!- nothin like chevy orange) and the cast iron manifold helps with that. BUT NO SHINY STUFF UNDER THE HOOD! I have one other question for the experts........again, the PO and others told me I want to tap and plug those exhaust ports in the front deck of the manifold, and he also suggested I could epoxy over those plugs. Question though, does the middle section of that exhaust channel play any role with the carb, how much of that channel can be filled, and SHOULD it be? does it play any other role? Ed |
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07-05-2012, 02:13 PM | #18 | |
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Re: buying rebuilt q-jet
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07-05-2012, 02:16 PM | #19 |
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Re: buying rebuilt q-jet
My engine is pretty stock. It's a 350 with headers, the Sean Murphy Stage 1 Q jet on a cast iron intake like the one in your photo, and a very mild camshaft. It's a Summit brand cam (I'm told they're made by Melling) with .398 lift on the intake and .430 on the exhaust. It's very close to a stock L48 Chevy cam.
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07-05-2012, 06:43 PM | #20 | |
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Re: buying rebuilt q-jet
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thanks for that info. I have yet to figure out what the factory cam is in my low milage C-60 350. consensus seems to indicate this will be a low RPM high tourqe cam, I'm just going to go with it, and if I cant get this motor to run right, I guess I could change it out. High tourque, low RPM works for me. Another question, you may or may not know....does the designation "stage 1" mean the same thing across vendors, or is it just a coincidental designation some use? lastly, would you know the original application for the carb you have, and if it's the same as mine, did you modify that manifold by plugging those exhaust ports in the front at all? -Ed |
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07-06-2012, 09:52 AM | #21 |
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Re: buying rebuilt q-jet
I think it's just a coincidence that both Sean Murphy and Summit use the "Stage 1" designation.
i don't know the original application for my carb, but it does have electric choke, which works very well. I did not plug or epoxy that heat passage in the intake. You can share that photo of your intake with Sean Murphy and he will provide the correct base gasket to go between your carb and intake. |
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