[importeater65]

I recently installed a Holley 670 cfm Double Pumper on the 289 in my '65 mustang, and i am unsure as if it is too much fuel for my 289. it seems to lug down alittle in the real low rpm's but in the high rpm's it screams. i dont notice any smoke, or anything like that. but am i losing much power?

-Dusty

[trashline]

well holleys are very easy to adjust. if you don tnotice any bogging at all then id assume it to be good.do you have any modifications done to the motor? if it is a stock 289 personnaly id think that to be to big. i would go with something around 500cfm if you do notice bogging test and tune till you get what you like. adjust the jet size if need be.you will notice a decrease in gas milage if coming from the stock carb big time i think. well you did say "lugging" down in lower rpms i would try to lean out the fuel mixutre a bit .this way you dont waste fuel. i dont think your really loosing power, but i do think your not getting the most out of the carb. if you tried to lean it out a bit already. then adjust the jets. or call holley and ask there opinion on what you should do. they are probably better then me

[BadlandsGhost]

The VE formula (rule of thumb) for carb size is supposed to be rpm x cid / 3456. So for a stock (ish) 289, that works out to 500ish CFM theoretically being plenty. 600 is from my understanding the outside edge of the envelope. I would say 670 would be a bit too much, even jetting it down. (Wish I had known that before replacing my old 600 with a new one )
J

[importeater65]

thanks guys... that helped, i think ill call holley and see what they suggest. but also, my engine isnt close to stock. i have rebuilt it with almost all high performance parts. .448, .472 cam with 204 deg intake duration and 214 deg exhaust duration. i also have 9.5/1 compression, a Torker II 302 intake manifold, Hooker Competition Headers, and now a Holley 670 cfm Carburator.

Thanks Again... -Dusty

[trashline]

your profile says you have 300 + hp. how bad is the bogging? how long does it last lets say you floor it and it stumbles for a 10 seconds, or if it just bogs real quick and then it takes off. if it does the second option then i would say try jetting it. or playing with the acc. pumps. if it is really bad i would down grade the carb size. 670 is a pretty big carb for a 289 if you think about it. the stock autolite 2100 is pretty low and now with a four barrel at 670 is alot to take in. you did say it wasnt smoking. i say give holley a call askthem what to recommend for your specific application and tell them if you can try to manipulate the carb you have now to run better im sure they can help out

[htwheelz67]

with your combo, a performer even a performer rpm will run circles around the torker2. a carb of about 525-600 will be adequate. If you have an automatic you want vaccuum secondaries if its a stick then a double pumper will be OK but with the mild cam vac secondaries will even be better. I run a 650 vac sec demon on my 351w with roller cam and TW heads and it makes more power than my old edelbrock 750 ever did.

I'd say a 575 road demon carb would really wake up your motor big time, and also a performer mani or even better a weiand stealth. The torker 2 needs at least a 214 @0.50 intake duration on the cam and actually an RPM or stealth will make more power all the way around. The torker 2 was a good idea but the original torkers made more power but at the expense of low end so they shrunk the runners to add more low end but its mainly a small runner low profile single plane and a performer is much more matched to your combo.

I have learned the hard way, bigger isn't always better when it comes to cams, intakes and carbs unless properly matched.

The torker 2 is only a good option when hood clearance is an issue and does not perform any better than a performer,rpm,stealth or victor at any rpm range except maybe 5500-6000 over the performer but the performer with its superior low end and mid will get you down the 1/4 quicker.

my 67 vert http://htwheelz.smugmug.com