The perfect use for holley carbs

So what is the correct rebuild kit for these carbs ? I searched through the books for awhile and didn't see much for them.

 

The power valve is designed to add an extra shot of fuel when you step on the gas. In part, this gives a smooth transition from the idle circuit to the power circuit.

Blocked off power valves are a bad idea, espeically for the street. With no power valve, you will need to bump the main jets up A LOT (5 to 10 jet sizes) to compansate for the extra shot of fuel the power valve would have added.

You end up running really rich, unless you are at WOT all the time...

I am running the same carbs on a tunnel ram. You can get them to run good (on the street), it just takes a little tuning work, and time.

 

I got a great book off of Amazon Called Holley Carb Handbook as I was bored with having to ask other people how to set up my carbs. Not sure how knowledgable you are but it might be a good idea to start with a good book and see if you can learn your way out of the problem.

And dont worry about coming over as arse, I think we haver all been guilty of that when it comes to frustrating car problems.

Hope you get it fixed.

P.

 

I got the problem fixed with my Holley 450s. I yanked them off and put a new set of 450s that a buddy of mine had. What a difference, the are very well mannored. No more popping, sneezing, backfireing and no more fuel running out the exhaust.

Four different people worked on my old ones and no one could get them to work. If you see a set on eBay for sale DO NOT BUY THEM, they will be mine.

 

I have the dreaded 450 cfm Holley carbs on my 396 w/Edelbrock cross ram. Key to these is having the 50cc accelerator pumps. They aren't perfect but they work pretty good IMHO and experience.

 

I'm the farthest thing from a Holley expert but I've been trying to read up on combo's other guys have had success with on the street. There doesn't seem to be a lot of love for the 450's. Seems people have had better luck with the 600 vacuum secondary carbs or even double pumpers. Also, as far as runner length I thought it was the tall tunnel rams that were better on the street? Interested to hear more on the topic from guys that run them.

 

It’s the little “tune” things that make them work on the street. The plenum is quite large and needs a good squirt to get off idle when driving on the street which is your “deadspot. Once you get that correct you can start on mixture for cruising and top acceration each having it’s own parts to change quite a few times to be really drivable. For a tinkerer it’s no big thing. If your not a gear head I’d do something different.
Before you start…..buy gaskets, bowl seals etc……lots of them.

 

Does it really matter when a thread is started. It's all relevant information. Do you throw workshop manuals away because they were 'posted' in the 1930s or do you use them for reference material?

 

I grew up working on Holleys and really love them on everything. It's just like the Ford vs. Chevy thing. People gravitate to things that are familiar because they are comfortable w/ it. If you aren't comfortable, learn or more on to what you know best.

Joe

 

To answer your question, NO it does not matter but it always funny when some new guy chimes in like the room is still full.

 

You have to be smarter than the carburetor . I've had dual wcfb's , AFB's , holley 390's , 450's , 650's, 660's & 750's ,some require more work than others , putting them in a situation where there's not a chance in hell for them to work certainly doesn't help .

 

Those twin Holley 450's that are listed as carbs to be used in dual quad setups are total crap! And I love Holley and Quick Fuel carbs. But those carbs should never have been designed to be used on an engine that sees mostly street driving.
I bought a pair for my SBC with an old Holley Pro Dominator tunnel ram, and it took numerous changes to finally get them to not stumble and try to die when driving normally and gradually transferring into the secondaries. Those 450's are a mechanical secondary carb, but what everyone is missing here is THEY DON'T HAVE SECONDARY ACCELERATOR PUMPS! So when you open the throttle slowly the engine noses over with the extra air flow, but no squirt of gas to go with it.
At the drags they're no problem as you mash the throttle wide open, and they work fine at full throttle. They also work fine at partial throttle where you only use the primaries. But anything else and they work terrible.
I got mine working as good as possible by changing the accelerator pumps from 30cc to 50cc. Then upsizing the squirters to a large enough size to get a better shot of fuel. Mine have just a tiny stumble when transitioning, and I've lived with it for almost a decade.
My intake wont allow a 1850 vacuum secondary carb side by side, and it wont allow inline mounting either. My only other choice would be side by side double pumper carbs, and I will someday dump the 450's if they ever give up, and need a rebuild. I've used 1850's together on tunnel ram setups several times and they're fantastic. I have a new pair here, and would use them if they'd clear each other side by side.

 

Here is good info from our old friend Brent RIP that owned our local Speed Shop. He sold two or three PALLETS of Holleys a year. When I once asked him (20 years ago) about the Holly reputation he replied, "next time ask the 'expert' if he ever tried a new Holley or just bought the same swap meet/racer junk that had been traded around our small town for years?" I bought a new Holley from him that day.