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Hi guys!

I'm tuning my Holley 4150 650 DP #4777-3

Does anyone know the size these restriction has on the #4777?
Idle Feed Restriction:
Power Valve Channel Restriction:
Idle Air Bleeds:
Hi Speed Air Bleeds:

Is it more restriction I can work with for better tuning Holley 4150 #4777?

Which books about tuning Holley 4150 can you recommend?

Some great tuning webpage?
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Holley catalog shows
IAB .028
MAB .072
PVCR .062
IFR unlisted but typically @.040
idle transfer slot feed[intermediate] is usually @.060
increasing holes .002 larger is @ 6-7% more flow
accel nozzles .028 pri/sec
powervalve#65


HP books has a good tuning book isbn ; 0-912656-48-4
SA design also has a book; isbn 0-931472-08-3

David Vizards performance tuning books are very good.PM me if you need more info
quote:
Which books about tuning Holley 4150 can you recommend?


I was hoping someone would recommend my book, but if noone else will, I'll do it, Tuning made Easy answers your questions, see link below. You're also welcome to PM me with specific questions, or we can skype as I just did with another Pantera community member...
Hi Joe
First I must say that my knowledge is more about tuning a functioning carb than fixing it. But let's give it a go. I've never heard of that problem before. Do you run regular gas? Live 10 feet from salty water? I assume the symptom is that you almost no acc pump squirt, and therefore it bogs down terribly? Or? Can you describe symptoms more?

Here's what I would do:
1. Next time it's been standing, don't start it, take of air filter, look down primary venturis, move throttle. Is there two solid pump squirts? If yes, it's not the ball, if no, read on
2. Take it apart, clean it, maybe change the ball from a repair kit, could be faulty material/size, just guessing. If fixed, good, if not, read on
3. Sometimes you have to give up. I had a Holley off and on a car 15 times to fix a problem, realized life's too short, bought a new Summit carb, no problems since. The Summit carbs also don't need as much continuous adjustments as Holleys, probably due to the material they're made of. And I can see that you're not a stranger to installing a new carb...

I'm interested in hearing the solution
fuel has alcohol and other corrosives additives in it. try adding a few ounces of MARVEL mystery oil to your fuel, when it is going to sit . I regularly add to oil and fuel ... seems to help with vapor lock here in the desert.
Holley also makes a rubber flapper check valve that replaces ball / retention strap.
quote:
Originally posted by Joe 1974 L #6656:
Hi Mikael,
I have a Holley question, my holley which sits for a while (sometime 2-3 months at a time while I am away working) has to be removed from the car and the balls that block the accel pump are always stuck, any idea's. I am thinking about going back to the stock carb. it never let me down.


This is normal for a Holley. As the fuel dries, it condenses into a varnish. The varnish will eventually dry into a glue.

This is also happening to the needle and seat in the carb. Those will tend to dry in the open position and sometimes the float will dry in the full down position along with them.

The design of the accelerator pump diaphragm, not only will dry with the ball stuck, but in addition, the diaphram itself needs fuel in it to keep the material from drying out and cracking. That material will eventually fail.

There are those that will take a half a cup of fuel and dump it down the throat of the carb and start the car that way. They take no consideration of the issues I just described. Many will say they have been doing this for years with no problems. They need to define the term...problems. This is nothing more that playing Russian Roulette.

Holleys cannot safely be let to go dry with gasoline in them. Webers with the glass ball needle and seat are a different story. They don't use gaskets on these items that dry up.

The safest thing to do with the Holley, is to prime the carb with an electric fuel pump for two or three seconds, then let it sit for a while. That can lubricate the needle and seat, float, and pump diaphram enough but this isn't going to work forever. Eventually they will all leak and leak big time.

Better to find someone to start and run the car about every 10 days while you are away.
Last edited by panteradoug
quote:
Originally posted by PanteraDoug:


This is normal for a Holley. As the fuel dries, it condenses into a varnish. The varnish will eventually dry into a glue.



Yes i agree, i've experienced this phenomenon myself many times and that varnish can be a so and so to remove as it also forms inside many small passageways inside the metering blocks and carb body.

There is no really simple and easy solution to it other than as Panteradoug says "start the car up every 10 days" or so, or be prepared to rebuild the carb before driving.

The solution i came to in my instance was i changed to EFI. The fuel system is sealed and there is no evaporation between starts, so no chance of gum and varnish formation.

I left one car for a year one time and when i did go to start i it started like it had been run the previous day !

You don't have to go for elaborate multi point systems there are a lot of bolt on throttle body setups available these days that will just fit straight on where the carb was.

It will have the added benefit of that you will pick up considerable extra power and driveability if tuned right.
quote:
Originally posted by markIV/ 4280:
the august issue of street rodder has an article about ethanol added fuel discussing corrosion and vapor lock, and related fixes.


can you scan the august issue of street rodder article (in readable size) and post it here?
I have sent you a PM.

Mikael, your book Tuning Made Easy, is of course already on my buy list... ;-)

goes all holley metering blocks be converted into adjustable with 6-32 screw-in tuning bleeds? was thinking of buying 6-32 allen head and drill them.

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