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05-25-2008, 10:48 AM | #1 |
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q-jet
i am building a 327 sbc. and i am NOT a fan of HOLLY carbs or any other carb but a q-jet because that is what dad has always ran and we have had problems out of hollys and thigs like that before in the past. my question is i have a 800cfm q-jet off a turbo trans am that has an ele choke is 800 cfm to much for a 327 should i find a 750 carb. i ma going to be running 202-160 double hump heads flat top pistons and it has been punched .040 over what should i do?
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05-25-2008, 11:54 AM | #2 |
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Re: q-jet
800 is a little on the large size but because of the small primaries and large secondaries it may work ok for you. If it were me I would run it to see how well it works before looking for another carb.
How is the carb identified as an 800 CFM? Jim
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1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end 1965 Impala SS 400 sbc, Muncie rock crusher 1966 Impala SS 396 bbc, TH 400 1969 El Camino, 350 sbc, TH 350 1971 Snowplow built on a Blazer frame 1972 GMC Short bed, stepside, TH 400, 427 BBC |
05-25-2008, 01:06 PM | #3 |
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Re: q-jet
The thing about a q-jet is that it is a variable cfm carb. Your motor will only use what it needs. I am quite sure that that carb will be fine on your 327.
Wa tare the numbers on the carb? They can tell you for sure what it came on.
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05-25-2008, 02:49 PM | #4 |
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Re: q-jet
To be honest with you...I hate holleys. I throw everyone I get my hands on in the scrap pile. The q-jet unless its a Carter one...I try not to use. I have found that a Edelbrock carb has never given me problems. Right out of the box and onto your truck. If you have the extra cash...try one. I think you will be surprised.
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05-25-2008, 05:30 PM | #5 |
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Re: q-jet
The way to identify an 800 from a 750 is by looking through the primary bore of the q jet. On the 750 the outer most venturi is completely round, where the 800 has a small bump where they couln't make the venturi bigger do to the passages.
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05-25-2008, 06:13 PM | #6 | |
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Re: q-jet
Quote:
Don't throw'em away. There's plenty of us who like getting all the HP we paid for out of a motor. You know, some of us who do have to the patience to do a little bit of tuning to get it. I wonder how many edlebrock, and q-jets you'll see at the local racetrack tonight? I'm just kiddin' around, kinda. I guess thay all have their place. And my Holley's place is on top of the intake where it belongs. Each to their own. Jay
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05-26-2008, 07:51 PM | #7 | |
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Re: q-jet
Well I guess I have a problem with Holley due I was always adjusting the one I had on a El Camino. One early morning, I was awake bright and early...6 am... Decided I needed to get up and tune that damn carb again. I leaned in and and revved the motor to see if it stumbled...where I had my hand was on the fender close to the radiator support. One of the fan blades broke off and hit my wrist. I thought that a screw driver fell into the fan and hit me. I stepped back... leaned into my Monte Carlo and I seen this trail of blood going down the hood...I looked at my wrist and the bone was sticking out. The fan blade had went thru the bone in my wrist.
Too clear things up...my hand was on the fender...not close to the fan. I was on the left side of my El Camino. So 2 things I dont use anymore on any car or truck I own...clutch fans and Holley carbs. Quote:
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05-25-2008, 05:43 PM | #8 |
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Re: q-jet
I've had my q-jet for years & its been nothing but good for me. My carb is on my 327 & runs excellent. The 800cfm should be no problem with a proper tune & due to the small primaries, will run great.
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05-25-2008, 06:00 PM | #9 |
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Re: q-jet
I think the reason so many people dislike Q-Jets, is that it seems more often than not, the throttle shaft wears from so many years of use. It needs to be rebushed where the throttle shaft runs through. I years ago rebuilt a few and even after a good rebuild kit, it wouldn't run right even then. A older guy told me about the throttle shaft, and how wobbly it was. After that they ran great. I enjoy these carbs because of what people say, small primaries and large secondaries.
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05-25-2008, 06:14 PM | #10 |
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Re: q-jet
I like both, I run a modified Holley on the big block in the Chevelle with no issues, and a Q-jet on the small block in the truck and no issues at all with that either.
You can't beat a Q-jet for efficient metering though, next best thing to fuel injection I say.... Now, is this carb off of the turbo car a blow through or does it sit on top of a manifold? Blow through carbs are set up differently.
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05-25-2008, 07:32 PM | #11 |
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Re: q-jet
800cfm vs 750cfm pics:
http://dyeager535.topcities.com/qjetidentify.html
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05-26-2008, 02:26 AM | #12 |
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Re: q-jet
neonlarry,
Thanks for posting the pics. The information was very helpful! Jim
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1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end 1965 Impala SS 400 sbc, Muncie rock crusher 1966 Impala SS 396 bbc, TH 400 1969 El Camino, 350 sbc, TH 350 1971 Snowplow built on a Blazer frame 1972 GMC Short bed, stepside, TH 400, 427 BBC |
05-26-2008, 10:06 PM | #13 |
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Re: q-jet
800cfm Qjet will be fine. GM used 800 cfm qjets on 301 and 305 smog motors.
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05-27-2008, 04:51 AM | #14 |
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Re: q-jet
you know what your talking about because it is offa 1980 301turbo trans am motor that has a smog pump. is there a smaller cfm q-jet with an ele choke?
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Greater love hath no man than to lay down his life for a friend. Members i Have met Earl Slick68 1969 Stepside Build thread http://67-72chevytrucks.com/vboard/s...=1#post4253546 Chevy Trucks the longest lasting most dependable trucks on the road |
05-27-2008, 06:55 AM | #15 |
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Re: q-jet
Get a 73-74 core and change choke internals from a later carb. Even electronic qjet choke will swap. Choke housings are the same. Just drill out the rivets. I took some pics. My work bench is a mess right now.
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