Help with Holley Specs
Thread Starter
Burning Brakes
Joined: Jul 2000
Posts: 1,118
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Help with Holley Specs
Need a few pieces of info for the Holley 4777 (650 DP).
1. Stock pump cam color.
2. Size of primary metering block idle feed restrictor.
3. Size of Primary metering block idle air bleed.
Thanks!!
1. Stock pump cam color.
2. Size of primary metering block idle feed restrictor.
3. Size of Primary metering block idle air bleed.
Thanks!!
Thread Starter
Burning Brakes
Joined: Jul 2000
Posts: 1,118
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Re: Help with Holley Specs (Brettmc)
Tnx. I've got several carb spec charts, but they don't show these details. I'll probably have to give them a call. Maybe those of you that bought a new Holley can chime in with your cam color and list number.
I have all the various cams and specs on cam volume and lifts at various throttle degrees, but just curious to find out what the 'stock' cams may be.
:steering:
I have all the various cams and specs on cam volume and lifts at various throttle degrees, but just curious to find out what the 'stock' cams may be.
:steering:
Thread Starter
Burning Brakes
Joined: Jul 2000
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Re: Help with Holley Specs (clem zahrobsky)
Tnx, Clem! That's what I suspected from a reference in one of my Holley tuning books (it didn't say it was the standard cam, but commonly used). My DP came with two pink cams, which dumps lots of gas. I gave the white cams a try today and it performed much better for me. I've tried various combos of cams and shooters, and it seems everything that works best has been at or very close to factory specs.
I'll see what I can find out from the metering block#. I'm resolving a rich idle condition, and I suspect it's from some metering mods. I've tried .010 and .015 wires in the restrictors and have some .019 wire I may also try. I've also replaced the drilled throttle plates with stock plates. Much improved...
I do have a couple other questions...
Those blue non-stick gaskets have been said to be a problem (restricting passages) if the bowl bolts are too tight by overcompressing the thick gaskets. Is this right?
When inserting restriction wires in the idle feed, is it better to form a L shape with one leg held in place by the gasket --or-- a V shape with one end inserted into the adjacent hole? The V shape is referenced in my books, but the L shape seems to be more common on the forums.
:chevy
I'll see what I can find out from the metering block#. I'm resolving a rich idle condition, and I suspect it's from some metering mods. I've tried .010 and .015 wires in the restrictors and have some .019 wire I may also try. I've also replaced the drilled throttle plates with stock plates. Much improved...
I do have a couple other questions...
Those blue non-stick gaskets have been said to be a problem (restricting passages) if the bowl bolts are too tight by overcompressing the thick gaskets. Is this right?
When inserting restriction wires in the idle feed, is it better to form a L shape with one leg held in place by the gasket --or-- a V shape with one end inserted into the adjacent hole? The V shape is referenced in my books, but the L shape seems to be more common on the forums.
:chevy
Le Mans Master
Joined: Mar 1999
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From: delmont pa
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Re: Help with Holley Specs (Chris69)
never had any problems with the gaskets and i use the "V" shape into the hole next to the IFR except when the IFR is at the top of the groove. make sure the ITS is not open more than .020. make sure you idle off of all 4 barrels by making sure the secondaries are open as much as the primary. set both at .020 on the bench and if too fast a idle close both down the same amount
Thread Starter
Burning Brakes
Joined: Jul 2000
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Re: Help with Holley Specs (clem zahrobsky)
I'm assuming the gasket 'issue' is not widespread, if at all. I happened to catch that blurb on one of the 'tuning' sites.
The IFR on the secondary metering is at the top of the slot on mine. I started off with .020 on all the transfer slots and idle is just under 1k (and pretty sure there are no vacuum leaks, but initial timing is up which contributes to this). The secondary plates will stick if I completely close them (equally), but it gets the idle down to 700 rpms. 850ish rpms is the point for now where the transfer works with no flat spots. I can reduce idle rpms if I reduce initial timing, but then off idle is not as crisp.
I also noticed that the primary IT slots aren't exposed equally (either the slots aren't machined equally or something going on with the shaft). The difference is .008".
Thanks for your help! :cheers:
The IFR on the secondary metering is at the top of the slot on mine. I started off with .020 on all the transfer slots and idle is just under 1k (and pretty sure there are no vacuum leaks, but initial timing is up which contributes to this). The secondary plates will stick if I completely close them (equally), but it gets the idle down to 700 rpms. 850ish rpms is the point for now where the transfer works with no flat spots. I can reduce idle rpms if I reduce initial timing, but then off idle is not as crisp.
I also noticed that the primary IT slots aren't exposed equally (either the slots aren't machined equally or something going on with the shaft). The difference is .008".
Thanks for your help! :cheers:
