Recent Posts

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1
Lobby / 350 vortec crankshaft info
« Last post by quadrajam on May 15, 2024, 06:34:08 AM »
Does anybody here know or can find out the target bobweight of a 350 vortec
crankshaft? Keep in mind there are 3 different 350s and 1 305 crank that have
the same casting number. What I need to know is bobweight for the vortec crank.
Thanks
QJ
2
Quadrajet Carb Talk and Tips / Re: 17057216
« Last post by Kenth on May 15, 2024, 01:06:41 AM »
This will help a lot:

https://cliffshighperformance.com/product/how-to-rebuild-and-modify-rochester-quadrajet-carburetors
3
Quadrajet Carb Talk and Tips / 17057216
« Last post by Mlcdc1 on May 14, 2024, 06:21:03 PM »
Picked up a 17057216 at reasonable price and would like to use it on my 1977 GMC C15 with original stock 350 engine(no modifications) & auto trans.  Can you recommend a rebuild kit and offer any suggestions on what to look at and on getting dialed in?  Thanks
4
Lobby / Re: leaf spring traction
« Last post by lightning boy on May 14, 2024, 04:39:30 AM »
Really excellent points. Thanks for the advice. Do you happen to have a pic of the pinion snubber you made?
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Diagnose a Quadrajet carburetor problem / 7043251 set up advice
« Last post by 69442 on May 12, 2024, 07:58:18 PM »
I have a 1969 442 convertible with a true 9.6-1 455 Olds in it. It's essentially stock with big valve heads, TRW cast pistons, an old Erson Viking 100H cam (depending what cam card I read online it's either 223/223 at .050" on a 113 or 233/233 on a 113. It seems a little too smooth an idle for 233/233 to me so that may have been a typo), Edelbrock Performer intake, recurved HEI and repro 2 1/2" exhaust manifolds and exhaust. I run it at 15 degrees initial timing and about 36 degrees total. I have a 200-4R trans, stock 12" 2000+ stall converter and a 3.91 rear axle. It was running pretty well but the carb was built in 2013, developed a slight hunt to it at hot idle and the exhaust was starting to smell rich. I figured I'd re-gasket it, look everything over inside and update it to more current parts.

It was set up with 69 main jets, 49B primary metering rods, .041" fuel pickup tubes, ,064 DCR, .070" upper main bleeds, the lower bleeds are bigger then .050" and smaller than .070" (I didn't think to measure them till I had the baseplate back on and didn't have anything between 050" and .070" I could bend 90 degrees to measure with), idle adjustment screw holes drilled to .089", AU secondary rods and blocked idle bypass air.

I changed it to 72 jets, 48B metering rods (next size down I have in stock was .041" which I thought was too small), .055" DCR, .038" pickup tubes, and added idle bypass air with .065" base plate holes. It runs very well and has 17" of vacuum at idle. It still smells slightly rich at idle but that may be as good as it gets. I'm open to suggestion on further tuning advice if you guys have any though. I thought the primary rod to jet ratio was supposed to be around 30 digits apart but it wasn't when I got in there and it was supposed to be set up like a 1970 Olds W33 engine (455/390 HP Delta 88 Police option). Thanks!
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Buy Quadrajet Parts, Quadrajet Kits, Service / Rebuild kit for 17057216
« Last post by Mlcdc1 on May 11, 2024, 04:53:27 AM »
Picked up a 17057216 at reasonable price and would like to use it on my 1977 GMC C15 with original stock 350 engine(no modifications) & auto trans.  Can you recommend a rebuild kit and offer any suggestions on what to look at and on getting dialed in?  Thanks.
7
Lobby / Re: Looking for some advice on a stock sbc 350 build
« Last post by quadrajam on May 10, 2024, 06:02:11 PM »
Thats good information to know. I ended up finding a TRW wide set on ebay NOS. One day when
I get caught up I will swap it out.

QJ
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Dialing in your rebuilt Quadrajet carburetor / Re: Mods on a 7041262 for a RAIV 455 engine. Are they OK?
« Last post by MattK2 on May 10, 2024, 06:06:19 AM »
I have a nice variety of jets and rods to work with now. Will block off the secondaries to assess primary jet performance. Once that’s good the rods will be dialed in.
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Diagnose a Quadrajet carburetor problem / Re: 7041540 Buick 455 goes lean at WOT
« Last post by Rhett on May 10, 2024, 05:32:14 AM »
and Cliff BTW I see the fuel pressure from a couple years ago was regulated at 6.5 or so.. and back then too the lbs per hr reverses significantly. I wouldnt think that would happen if the bowl was looking for more fuel unless there was turbulence in the path. I never could figure whether that was a chicken or egg condition, but the RPMS were still climbing even if HP levelled off....
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Diagnose a Quadrajet carburetor problem / Re: 7041540 Buick 455 goes lean at WOT
« Last post by Rhett on May 10, 2024, 05:21:18 AM »
So I said 6 but it could have been 7, it was regulated for Quadrajet use on the dyno and feeding the carb direct. This same thing happened with this carb on a different dyno a few years ago, but it ran so well in the car I just dismissed it as a fluke. In the car, this was running 12.4's-5's and never missing a beat and given the build and HP thats exactly what I was expecting, it was putting out the MPH that I would expect from the Holley pulls (435hp/516tq). It wasnt as lean at WOT as it is with this cam, but I never really bothered to spend a lot of time finding out either. The car has a AC pump and stock fuel lines.

Fast forward to this build, and the car is again on it's way to putting out the MPH I would expect from the new cam (441hp/544tq)  and while it's somewhat lean at WOT (13.5 if you trust a tailpipe bung), it runs great, idles clean and low, pulls good vacuum, great throttle response, clean fuel  delivery to 5700 etc..I just dont want to leave anything on the table.

I've got two other 540's, one built and testing, one ready to bubild. This car likes a lot of fuel and a lot of bypass with my current carb, but I may be covering for too much bypass with too much fuel because I just stairstepped my way into the current config till it ran right. I'd like to take a more scientific approach with the next two, and make sure I kick that Holley's ass. 

Lightning Boy, I'll throw some sheets up from the dyno sessions three years ago.while I dont have EGT's, there is more info there. I couldnt run the air flow meter cause we coulnt cobble it to the air cleaner base at the time and clear the dyno throttle linkage.
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