Well i was just trying to gather some info on carb selection for a 455. What size do you think the motor needs: 464 CID JE 10-1 pistons approx compression 9.6-1 stock rods stock crank stage 1 heads with 3angle valve job and bowl blending no port work crower cam .507 234@.05 intake and .525 245@.05 exhaust 1.6-1 roller rockers eldebrock intake What carb size Right now i have a holley 750 vacumm secondary on it the motor seems to fall off bad at about 5300. Cam is rated from 2500 to 6200. Pulled the plug and looks a tad lean, but before i start changing things, is this even the carb i want? Now if i put an 850 on it will it get sloppy pedal resopne down low or is this what the motor needs thanks:3gears:
A lot of the guys on the forum swear by the 800 cfm quadrajet for the street. I am one of them. Mike D.
i mean no offense to anyone but i just can't see putting a quadrajet on the car. if you were to put a hooley on what would it be an 850 doublepumper 800?
If you're looking to use the car to drive around town and on short trips, then a qjet is your best bet. If you go with a DP, then your gas mileage will look like :moonu: no matter how much you baby it.
I've used both holleys and Q-jets on several Buick engines and find that they (the engines) like the Q-jet much better. They run very strong! Ask around the site, you'll see that the Q-jet is a better all-around carb for street/strip use. In fact we have people on this site running into the 9's with a Q-jet and then drive their cars home on the same carb. I've sold all of my holleys and will ONLY use a Q-jet on my Buick baby. :bglasses: I'd say give the Q-jet a chance if your going to do any street driving, I think you'll like the throttle response and the better gas mileage to boot. In some cases brand loyalty may cost you ET's and $$$ :Smarty: Cheers
I used to have a big block, ran a Holly 750 vac secondaries for some time, could not figure out the spark-knock, ended up finally going to an 800 double pumper, that took care of it and look out! It ran great, but it really sucked the gas...I now have a milder built 455, 9.25:1, stage-1 heads, TA 212 cam, I have an 850 Q-jet that Jon Osborne worked over, I have just got it out and running, am very pleased and can actually see the odometer move before the gas gauge! Kevin
I lot of people don't like qjets due to an over all complexity when compared to holleys. hence quadra junk and quadrabog That and they don't have the name recognition . If you talk to people that have got the qjets figured out then they'll tell you, "Set it and forget it." A qjet four barrel has the potential to get better mileage than a two barrel and buicks for one reason or another more than any other make low qjets, I'm not really sure why though.
the question is not what type of carb i want, (opinions are like butthole everyone has one,) it is what cfm would you get if you were running a holley. is the 750 vac sec. enough or does it need an 850 thats all i am trying to figue out i am not trying to offend anyone, just trying to get to the facts
Bryan, Give TA a call. Just 2 minutes on the phone and you'll have a decent recommendation. I'd say Holley DP 800 (#4780) or 850 #4781, but what do I know. I doubt you'll get sloppy response down low with that size carb on any 455 "torque motor". I run a "puny" Holley 750DP (#4779) based on what Dave at TA told me many years ago for my combo. I've pulled it off and swapped a few other Holley carbs in it's place, from 850 to 930, and have always gone back to my out-of-the-box #4779. Best 60 ft, MPH, and ET out of a $350 carb. Call Dave. That's my opinion (hee, hee). Ramin
mostly the size depends on the cubic ince and the max rpm, 800 cfm is fine for a 462 turning 6000 rpm 750 cfm is good to 5500 rpm.with your set up you should have good throtle responce no mater what carb as long as it set up right. just my 2 cents Kelly
#4780 800 DP worked fine for me.. NO problem with throttle response. Lots of problem leaning out on top end though, with stock fuel system! Ran bitchen after the new fuel system!:TU: I used to drive my car every day, and race on weekends! LOW 12's.
why don't you try jetting it first use # 70319 they are 72's or # 70319 they are 76's . then try secondary M. rod # 7034822 it might help instead of replacing the carb. My mistake i thought you had a q-jet on it
I have yet to see anyone recommend the 750 Holley Dominator. 4-corner idle, the big venturies, etc. etc. These carbs are just plain awesome. I use the 1050 on the street (I drove the car to work every day last week) and it works great. I think the 750 would work just as great on your milder combo. :Smarty:
