My first trip the 1/4 mile strip was yesterday. With the stock Q-Jet the car ran good for the 1/8 mile but it seems to lie down on the top end. Here are the details: 2.050 sec.--- 60' 6.069 sec.--- 330' 9.548 sec.--- 660' (1/8) 15.172 sec.---1320' (1/4) @ 87 mph I must have raced this slightly warmed over `01 Mustang four times. I would be in front always at the 1/8 but he passed me 3 of the 4 times by the time I got to the 1/4. His speed was typically 95.5 mph at the finish. After I got home from the drag strip I thought what the heck, I'll put the 800 CFM Q-Jet in. This is a carb. that John Osborne prepped for my 455 project that is running behind schedule. I thought why not work the bugs out (if any) with the 350 then it will be one thing I won't have to worry about with the 455 start-up! The car seems to run great with it, it feels at least as strong. Maybe it will help on the top end o No: Anyone else tried this?
Update with 800 CFM Q-Jet My seat of the pants first impression was right :beer Here are the before and after results: 60' 2.050 ---> 2.170 330' 6.069 ---> 6.100 1/8 9.5518 ---> 9.4374 1/4 15.170 ---> 14.888 mph 86.40 ---> 89.70 I could not get a good launch, using the same technique as before resulted in spinning hurting 60' and 330' times. But there was more power everywhere not just on the top end (as the numbers imply). Maybe I should also convert to HEI, it is just sitting there in a box on the workbench :grin:
Both 350 and 455 Buick engines like bigger carbs compared to other engines of the same size. I have a 750 Holley on my 350 motor and it runs great. Dont try and go by the "carb formula" for other engines when trying to figure out what size carb CFM wise to use on a Buick. When I had a 82 Regal with the 231, I swapped over to the 4.1 litre 4 bbl intake, and used a Rochester computer controlled 4 bbl. for a 307 Olds motor on it, that little 231 LOVED to breath:laugh: Mark
455 engines prior to `72 used 750 cfm carbs. In `72 455 carbs were 800 cfm. I have heard that it is possible that some `71 455 carbs came with 800 cfm ratings. My carb. number is 7043240 which stands for: 7 0 4 3 -- 1973 [year] 2 4 -- Buick [make](1-chevy, 2-GM or truck, 3-Cad., 5-Olds, 6-Pont.) 0 -- [engine/trans combination] My notes say get a `72 to `74 carb. Carb. number changed starting in `75 I think. Try this link it will help. http://www.buickperformance.com/qjet.html
Performance upgrade results (HEI) Just got back from the Fayetteville drag strip tonight. Since last visit I've converted to HEI. Here's the progress and I've made so far this season... Trip 1--->10.1 sec @ 69 mph (1/8) Trip 2--->9.55 sec @ 70.5 mph --->15.17 sec @ 86.4 mph (1/4) Trip 3--->9.44 @ 72.76 mph ---> 14.89 sec @ 89.7 mph Trip 4--->9.05 @ 76.32 mph --->14.26 sec @ 93.6 mph :beer Trip 1 - no tuning, 750 cfm carb., stock converter, headers and 3.42:1 posi, TH-350 trans. Trip 2 - converter TCI "2800" stall actual is lower, trans. prepped for 455 torque! Trip 3 - Installed 800 cfm (will go on 455 soon ) Had problem hooking :laugh: Trip 4 - Installed HEI ignition with MSD coil, cooler track temps. helped too. Man I'm really happy with the results so far this spring :TU: Sig. updated :Brow: All this preparation for the 455 is fun. Next upgrade the electric fuel pump and regulator.
Congrats Dude!!! Looks like it's running great. The way you keep power-tuning that little 350, it'll be running as fast as a 455 soon! That's exactly why I like the 350 soooo much. It responds so well to even the slightest modification:TU:
GREAT times dude! I like your method of tuning, just a little at a time:TU: I bet high 13's arent far away. I have the same gear and "I think" the same TCI converter in my 71 GS. Whats the rest of your combo? Heads, cam, intake? Really curious:grin: Mark
Mark, not too much more to add other than what I've mentioned above. The engine was re-built by a previous owner about 19K miles ago (standard bore I was told). All completely stock... here are some other details and facts: - "energy" cam, I have no idea but is probably one step above stock (smooth to very slight lope?). - 3.43: posi with boxed lower control arms (and rear sway bar) - cranking compression is only 110 psi. but pretty consistant - leak down test show only 1% or so. - AC - Headers and 2" dual exhaust - 255/60R-15 T/A radial out back mounted on 9" Crager Ind. racing wheels. 235/60R 15"'s in front on the same type wheels/tires, 8" rim - The car already had air shocks, I set them at minimum pressure (so it does not sit too high in the rear). - Battery in trunk. - It has a trans. cooler - HEI and 800 cfm prepped by John Osborne (for 455) - I've added a rally steering wheel and in-dash factory tach. - Automatic, bench seat. - I shift at 4700 to 4900 rpm at the track (this is 42 and 69 mph @ 4800 rpm). - Best 60' time (last Thur.) is 2.0254 sec.
Hi, I was wondering if a completely stock 350 can handle a 800 cfm carb? I found one from a '73 455 and I figure I would replace the one on my engine. The one I currently have on now needs rebuilt and the 800 cfm carb is already done. Thanks, Rob
Rob, my engine is very close to stock, and it's working great for me. My Q-Jet is set up for a 455, I'd say don't even hesitate go for that 800 cfm. It's an easy change, besides you could always changed back if you wanted to.
