Need a little help here ..... I bot a holley 950 HP from a fellow TCer, dyno time only but did not recieve any spec sheet with it . does anyone know what these carbs come shipped with re jetting and power valve geting ready to start up my new motor on dyno and would like to set it up close re jetting and PV ..... any suggestions for a 439ci BB (specs in sig)+ HVH 1" SuperSucker spacer,Stahl headers 1 7/8" with 3" collectors Thanks Bill.

78's square..I'm running 80's in back on mine,power valves are 6.5 I believe,I've had mine apart but didnt pay any attention to that,just changed jets and installed jet extensions that came with the carb. I love the carb. graemlins/thumbsup.gif

Thanks Robert ......so 950hp come shipped jetted 78 in all 4 holes and 6.5 pv ..... sounds to me might be close for my project maybe I should staart it up with the stock settings ...anyone else have some advice

Holley posts ALL their factory carb specifications (PVs, jetting, squirters, etc...) on their web site. You will need adobe acrobat reader to view this pdf file:

http://www.holley.com/HiOctn/ProdLine/CarbList.pdf

I'd say put it back to 100% stock specs and go from there. I run that same carb. I've been tuning on my current combo (trying different intakes, spacers, squirters, timing, etc...) for over a year and I'm not far from the original setup. Depending on your intended use you'll prolly find yourself wanting to up the pump shot a little (comes stock at .031 f/r as I recall). If you go up far enough in squirter size you'll need to go to a hollow screw, and if you go up really far you wil need bigger accelerator pumps (50cc vs. the stock 30cc) ;) I may have also changed the primary pump cam position. My jetting is close to stock in the front. I put a plug in the rear and jetted up to see if it would make a difference over the power valve. It didn't make a measureable difference one way or the other. As you know, every combo is different so your mileage will vary.

HTH.

Ken .......thanks for that link and info .....helps alot .. Bill

BTW where have you ended up with header size and collector length ....I know you have an auto car but just curious ....

Originally posted by CDN SS:
Ken .......thanks for that link and info .....helps alot .. Bill

BTW where have you ended up with header size and collector length ....I know you have an auto car but just curious .... Hi BIll,

I run Hooker Super Comp 2" primary with a 33" tube length. I recently (couple months ago) installed a set of merge collectors, too. I haven't been able to quantify the gain of the merge collectors as I didn't have enough runs in my weather station database prior to installing them. I was expecting to gain .02 or so in 60', but I don't think it happened smile.gif The car is a little quiter now, and it was pretty quiet before. Definitely doesn't sound like a 10 second car.

OK Thanks ...... my motor not quite what yours is but looks like I will go with 1 7/8 with a 3" or 3 1/4"collector ,I have had a lot of discussion with custom header designers these days more focused on Nascar / dirt track stuff , and they suggest that collector diameter is often overlooked ( most just tune collector for length were the heat stops) based on and even if your primary tubes are a litle large a smaller diameter collector will increase velocity and scavenge ability . based on an assumed HP my combo right on the edge of 2" or 1 7/8" .......I'll bet your hooker collectors were 3 1/2" and if you bot flowmaster merge collectors for 2 " pipes they should be 3 1/4" so interesting to see if any change when you can compare under same conditions ...... I'm being told to run 3"diameter collector even with 1 7/8" pimaries and at least 12 -15" long collectors ....... again thanks for info I appreciate it. Hopefully headers will be here soon and will post dyno results with 1 7/8 headers and 2 " dyno headers and 2 carbs ... assuming the motor starts up and runs and i can do mall that in 4 hours of dyno time.

I also run a Holley 950hp. and tried bigger jets due to being at sea level but ran to rich so went back to stock settings and after new plugs they showed perfect jetting! graemlins/thumbsup.gif

I'm trying to decide on a carb for my Elky's 427 bbc(10:1 Speedpros,XR282HR hyd.roller,Edelbrock RPM Airgap,MSD ignition,and Sanderson 1 7/8 headers with 3" collectors). I've been considering a Demon 750 or 850 w/vacuum secondaries but the Holley 950HP could be a candidate. What are your thoughts? 950 too large?
BTW,the tranny is a Viper T56 with 4.10 or 4.30 cogs in the rear planned. It's got a 3.50 cog now.

the 950 fits right in between your other choices 830 cfm...pricey too,but I feel it was one of the best investments that I've made.