I have never run a Buick 455 before, 1971 G/FA stocker 310/330 HP, and I use the term stocker loosely. I was told by the builder of this car to run a mechanical advance dist with 33 degrees total, now keep in mind this same builder had rubber bushing in the control arms that moved so much the tire would hit the wheel well, and a fuel system that would have problems supporting briggs 3 HP lawn mower, and flat wouldn't if you were mowing up hill. My questions are this: 1. Total timing 2. Q-Jet setup main jets sizes, Secondary metering rods, Hangers 2.5 Float setting 3. Fuel pressure 4. And any other advice specific to this engine 5. Launch temp The intake is leaking from the end seals, is a SCE gasket the one to use? Fuel system is fixed along with the rear suspension, the car is so rich now that it has fuel I need a baseline for the Q- Jet, racing at a 28.00 baro, 2130 feet altitude. Thanks for your help.
Locked timing at 32 to 34 8psi fuel psi 175 to 185 temp Carb settings id just hook a dual channel wide band up and see what it likes, id set float high as it will allow , and remember rear air door angle affects A/F also 90% isnt always what they want Just my opinion anyways
May want to post the carb #. Should be 7041xxx. A stock Buick 455 bathtub gasket and Permatex's "Right Stuff" sealant in place of the rubber end seals will work fine.
I think is was 1111, its IHRA legal for the 310/330 HP 455. He' got composition intake gaskets on there, machine work would have to be right for the valley tray to work, and I don't have any confidence.
Try 78 jets, AU rods and a J hanger, use 30-33 degrees total timing and type of ignition system, determine best setting by mph in lights.
If a good bit off milling has been done you maye have to go to composite gaskets from TA with a AMP splashshield, I myself use the rubber end seals when the gap is in the range acceptable
The quadrajet code is needed to determine what you need. If it is 7041240 carb start with 73 jets .043 primary rods DA secondary Rods O or higher hanger 9/32" float setting Fuel pressure 4.5 to 6# Get your carb number and I can get more specific.
If it has composite intake gaskets, then get some from TA or Summit/Jegs. I'd be concerned about a valley pan, so when you get the intake off if there's not one in there you can scab one from an old bathtub gasket or get the shield from Mike @ AM&P (preferred). I'd still use the Right Stuff for the end sealing. If the Stinger is set up properly and working, then set the initial @ 36-38, all in by 2500 rpm. It will pull about 1-1/2 to 2 per 1000 RPM after full mechanical advance, so that should be you at about 30 at the top 3rd gear depending on gearing, tire size, etc. If the carb is truly a 71 800 CFM QJET, I'd start with 75/43 in the primaries, DA rods and middle of the road hanger in secondary's, 5-6 psi fuel pressure, and 9/32" float. AU's are pretty hard to come by - I still have a set of originals from when I worked at Rochester Products back in the 80's.
Thanks, can I run the composites on top of the tray gasket, because he's got composite on there, and I believe no tray.
Heres what I got Q-Jet experts: 17054900111 1117 J hanger CC sec rods, .030 tip 75 primary jets NO primary rods .135 needle and seat .180 float level
Ive had a couple q-jets without primary rods, worked fine guzzeled gas but ran good,I also dont run the vac pull off for secondarys just use the spring. 75 is to fat without the rods tho 68 to 70 holley jet be better starting point. I also have cut booster rings out, took the ridge out of the primary bores, cut the chock tower off and profiled the edges, knife edged throttle plates etc and have track tested About every level of mods inbetween and just as Jim Rodgers had told me they would they all ran very close to each other. On his 10sec stock appearing car he has a full boogie 900+cfm qjet and carries a stock 1970 stage 1 750cfm unit that will run right with the race carb, ive seen him change carbs and run the same. All this maybe irrelevant I guess but just food for thought
Hugger, that's kind of the thing about these quadrajets isn't it. I agree, 75 seems big on jets without primary rods. 68 would be where I would start. But run the car and see where you are at with it. That's a Chevy carb btw
If there is no tray, not only are you splashing hot oil on the bottom of the intake, but the PCV valve is sucking oil into the engine. You can make a tray out of the metal intake gasket by snipping off the port part of the gasket and using the composites. Instructions for that are here: http://www.taperformance.com/PDF/Intake_Instructions.pdf Also, the composites come in various thicknesses so you can compensate to some degree for milling. http://www.taperformance.com/proddetail.asp?prod=TA_1710
Q-Jet 17054900 Today is the day we will find out, I will start with a 68 jet, around a .040 tip on the sec, 5 PSI, .280 on the float. Weight 3660 G/SA trim, It looks like about a 5500 foot Da 27.7 Baro around 90 GOW.
UPDATE: The car was raced today in the following conditions 27.69 Baro 108 GOW 5500 feet DA Best pass was: 1.539 60 7.16 660 @ 93.9 MPH 11.383 @ 115.97 Carb specs: 17054900 5 PSI J hanger 68 primary jet .040 tip secondary Timing: 33-34 degrees total @ 4700 RPM It seems the builder of this car was offended with some of my comments. When you buy a car sight unseen and the seller claims the car to run under the index and the car shows up with oil leaks so bad the car shouldn't even be raced, a Holley blue fuel pump mounted ahead of the lower control arms, the Holley regulator cranked all the way in, the wiring a horrible mess, its hard not to say anything, you look at things on this car and just shake your head and say why......would anyone run a car like this, the bushings were so lose in the car the tires would hit the wheel trim, one look at the videos you can see this. I wiil say this the car seems to run good after these problems were fixed, the engine seems to be good as a credit to Lyn, it had just better be legal when I get into it. All in all I love the car, and I look forward to going faster in it than you Lyn have ever been. BTW I had to jet the carb down from 75 to 68 jets after redoing the fuel system, I never got to the secondary side of the carb yet, although right off the bat I went to a .040 tip rod instead of the .030s that came in the car.
Nice runs Mark especially in those weather conditions !!! Was the car at legal weight during those runs ?
Thanks, I have to say I was very surprised, legal weight is 3660 in G/SA, they would not open the scales for me, I will weigh it this week. Im sure its light but the question is how much. Im considering going through the whole car and engine, I see a lot of potential there, theres a points race coming in Oct.
