Sorry, I meant "which" holley. Typing too fast. About to spring for a 4150 Double Pumper. Tech Support guy at Summit says the 750 will be more than enough for a car that doesn't see 6,000 rpm very often and will still move more fuel than an 800 quad jet. The builders that dynoed my engine used an 850 dp though and it made sick amount more hsorsepower than the 800 quad. jet. Like 50 more. Should I go with the 850 or is the guy right about the 750 being sufficient? I want to see 12's at Musclepalooza and I want it without having to think like Albert Einstein tweaking my QJ. I just don't have the time nor the patience. It's either that or spring for posi and 3.55's like I have been thinking about, but that's like double the coin. Any insight? I need to make a purchase like today to get it in time.
Id go with the 850. Sounds to me like the motor dynoed nicely with the 850, if it did then why downsize if the engine responded well to the 850. Im no expert by any means, but thats just my 2 cents...
Devon what's the "8162"? Just an old model number? I was looking at this one. http://www.summitracing.com/parts/HLY-0-4781C/
Ken go for that one. The stage-2 package used to feature the 4781. The 4781-C is the newer version, and it even comes with 4corner idle. BOP like bigger carbs, the rule that hes quoting only applies to chevies and fords. FYI, the 850 holley is the biggest carb the holley makes before the dominator. The 1000hp is actually the 850DP with no choke horn. The 950hp is actually a 750 in disguise.
It was an ancient model, one of the first with four corner idling and two power valves. The new 4781C with four corner idling will be great, just as Azeem said. Devon
Thanks gentlemen. Hey one more thing, what about choke? Did you need to rig up a manual choke through the dash somewhere? This carb is a manual choke. Also, was it PIA to connect the accelerator cable?
You can if you want, I haven't used one since the mid '80's. I always run the engine a bit to get the coolant temp up before I go for a drive, so spending a couple of minutes feathering the throttle is no big deal for me. Others may differ. You could probably run one of Holley's electric choke setups if you really have your heart set on it. Devon
Oh no, I don't have my heart set on anything, if I don't NEED it I can hold off. I still need to feather the throttle with my QJ. The mechanical choke just never seemed to work on it. Probably would be basically the same thing. Accelerator cable hookup? Any additional parts needed? o No:
Can't help you there...I run the original '67 solid rod accelerator linkage. You might need something like this, not sure. http://www.summitracing.com/parts/HLY-20-2/ Devon
Azeem, Elaborate on the "950hp is a 750 in disguise" thing. My builder recommended the 950hp, and what you just said has me a bit concerned (cause that carb wasnt cheap!). Sorry, dont mean to hijack...
950HP is a 750 main body venturi diameter with an 850 throttle bore diameter if I remember right. I've never seen it claimed that it would flow anything close to 950 cfm. Devon
Personally, i would mill the choke horn off completely, and set your fast idle to run around 1200-1500rpm or so. Hook a manual choke cable up to your choke. In a holley, it closes the primaries completely, and actually opens the secondaries a bit. The primary continues to dump fuel in, and thats how the "choking" happens. This works great for my brothers car. EDIT: Forgot to mention what "this" is. So when he goes to start the car up, he pumps the accelerator 5 times, pulls the choke cable and initiates the fast idle. The car fires right up, revs up to 1500rpm (just like a fast idle on a q-jet). Wait 2 minutes or so, and push the choke cable back in. It may be pull/push depending on how you hook it up. Works beautifully. Even if you dont mill the choke, i would get rid of the choke plate completely, it just restricts flow.
So as to not hijack the thread. http://www.v8buick.com/showthread.php?t=181581&highlight=holley+950+hp
By the way thanks for your input Shawn. I'm kind of thinking the same thing. The all knowing tech at Summit was just convinced that an 850 would be too much.
So after all your guy's help with this I am one click away yesterday from confirming an order online with Summit and my better judgment says to me "hey idiot, let me get this straight, you have butt loads of credit card debt that you still need to pay off from your engine rebuild and you're going to add another $547.00 to that because....?" So I backburner that idea and order some secondary metering rods and a carb spacer from Greg Gessler instead for a fraction of the cost. Gonna get another season out of the old 800 cfm it looks like. ou:
Here goes from a old fossil.... :laugh: putting on a bigger carb or multiple carbs does not increase the horsepower very much....the biggest benifit is that it cause the engine to rev and reach max power QUICKER.....That is why my favorite carbs are the old 950 and 1050 three barrels.... they are just like the 4150 to build, there is one air cleaner, one set of linkage to adjust, and the vacume secondaries work good.... now,, that said, I have a 64 riv with a 425 that runs really good with one of the little 600 cfm holley ''shoe box'' carbs on it.......and gets really good mileage.....The double pumpers dont have much appeal to me,, if it is dialed in , a single pumper works really good,,, I do use the ''Rio'' pump on my carbs except for the riv.... but the 3 brl needs it to cover the bog when the secondary opens.... also dont to forget to open up the air cleaner assembly for increased flow....and then the exhaust side needs to be free flowing to handle the increase.....remember, not much more power, quicker power...
