Help me with initial Holley Setup

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kc8lbn

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I need help setting up a Holley 850 Dbl Pumper for the initial firing of a motor. Lets call this one the ebay motor! Its a 76 440 bored 30 over, stroked too 500ci with a 440 source kit. I will be running IRON heads, 452 castings ported and polished. Cam is a comp camps extreme energy 295 grind, intake is a weiand team G. Right now the carb has 89's on the primarys and 91's on the secondarys, 6.5 pv on the primary and a blockoff on the secondary the choke bell has been machined off, I am running a 30cc squirter on the front and 50cc on the rear can't remember which cams I have? Any help or Ideas?

Thanks for your time......:cheers:
 
I'd say that going back to all original jetting, etc would be the smart way to go. Holley dp's usually are very close out of the box.
 
89's and 91's sound big, but you are running a stroker with a single plane intake manifold and the secondary power valve is blocked. Was the air horn milled off? The reason I ask is that's where the list number is usually stamped, and if I could get a list number, I could find out what Holley originally had in this carb.
 
If it were me, I'd swap in a 3.5 PV in front, and plug the rear. You want to make sure the only fuel going in is thru the idle circuit, then the jets. For jetting, it sounds ok to me. Also, you MUST prime a holley by filling it with fuel before initial starting. You rarely hear of it, but if you tunr it over with the key, you run a very good risk of cam wiping. You need to prime the carb (I fill with a small funnel thru the vent tubes..About 1/3 of a soda can of fuel in each bowl), then prime the oil system (which involves manually turning the pump via priming tool) and turning the engine over 2 full rotoations by hand. Then stick in the dist so it's close to 10° before TDC on compression. Then hit the starter and fire it.
 
Moper, I agree with priming the carb unless he's got an electric fuel pump, then there's no need. Definitely prime the oil system and get your dist. as close as possible. Excellent advice.

I'm not a big fan of plugging the power valve on a street car unless it's super/turbo charged, but kc8 didn't really state what his plans were. I just assumed street. Regarding the PV, do you really think his vacuum would be that low w/500 ci of displacement and that cam to require a 3.5?
 
carb was originally off a 73 vette with a 454, i'll pull the list number tommorrow but it had 81 jets both sides years ago when I pulled it apart for its first rebuild.

Thank you for the tips on priming the carb first though! I will be using a electric fuel pump, and the car will mostly be for street fun. Its a 70 Dart Swinger, but will see some track time....
 
Ram, the question was what to do to safely start a new engine. No, I dont think the 3.5 will be right... But, it definately wont creap open at idle either...lol. As far as plugging the secondary PV, Holley has a bunch of carbs taht came that way from the factory. It's for easier dialing in of fuel curves. Because there is little chance that a carb of that size will spend much time at 3/4 throttle under load.. More like either WOT, or just on the primaries. I forgot if it was here or another site... But someone once told me they plug both PVs on initial startup. I like the idea of making sure there isnt too much fuel when it fires. So I modified it a little. It will need to be tuned once things are briken in. Definately will need tuning after...
 
i thought that rule of thumb for holley with a PV, that front to rear jetting should be a 6-8 size difference?(i.e. 74 front, 80 rear) and square jetting for no power valves? i agree with the 3.5 until you figure out what kind of vacuum you have to work with.
 
moper said:
Ram, the question was what to do to safely start a new engine. No, I dont think the 3.5 will be right... But, it definately wont creap open at idle either...lol. As far as plugging the secondary PV, Holley has a bunch of carbs taht came that way from the factory.
Click to expand...

Good point regarding the 3.5 PV to prevent creep open on intitial fire up. I've never had a problem with it, but my timing light is in hand and connected and has a built in digital tachometer and advance, and the distributor hold down bolt is just tight enough where I can still turn the distributor by hand firmly. A screwdriver is also in my back pocket for immediate idle speed/mixture adjustments. Sometimes I just think way too far ahead and try to get it right before I even hear it run! Doesn't always work that way though..LOL.

I was not aware that Holley ever shipped their carbs with the PV plugged. Would you have a list number for these carbs? I'm just curious as I have never seen one. That's why I love this site. I'm always learning something new.

kc8,

Get me that list number and I'll get the stock specs for ya. You never know when they may be handy!
 
I'll have to get back to you with numbers. I'm pretty sure most 4150s bigger than 700cfm had the rears plugged for a long time. But I have a Holley book at home that has those factory specs and the list numbers. I had 2 800DPs (the old school 4150s) that both had plugs from the factory in the rear. And the PV channel represents about 8 jet sizes worth of fuel..Depending on what jet size you start with.
 
kc8,

You got an 850 double pumper (which you already know LOL!) model 4150.

Pri jets: 80
Sec jets: 80
Power Valves: 6.5
Pri shooter .031
Sec shooter .031

Here a link to the list number document from Holley. Very handy. http://www.holley.com/data/TechService/Technical/Carb%20Numerical Listing.pdf You will need Adobe Acrobat or another PDF viewer to see it.

Here's an exploded view: http://www.holley.com/data/TechService/Technical/4150-4160 Exploded View.pdf

Here's some additional documentation regarding how Holleys work and some tuning tips. http://www.holley.com/data/TechService/Technical/Carburetor Tech Info.pdf

Here's a link to Holley's entire technical library. http://www.holley.com/TechService/Library.asp

Moper,

Yes, you are right, the power valves do represent quite a bit more fuel. I used to start 10 sizes higher on secondary jets and drop down two jet sizes at a time till I felt or heard a bog, then go up one size at time on Holleys with the seconday PVs plugged. I always assumed at the time that the customer or previous owner had done it as the most of the customers stuff had leaky float bowl gaskets and plier marks on the bowl screws LOL! The link I posted for the exploded diagram does not show plugs, but these are, of course generic and may not apply to some of the older Holleys. Have a great weekend!

Joe
 
Thanks Joe, I didnt ge tthe cahnce to get those numbers for this post.. Busy weekend. I will try to remember to in the next few days.
 
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