Holley question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

cpetersen · 08-09-2011, 11:28 AM

I have a 3310-1 which is a 780, metering blocks and 2 powervalves. I'm still having a occasionial backfire through the carb. And only when you are just giving it gas. Once every 2 weeks. Well it pops one or both powervalves everytime. I'm running a 6.5 in the front and a 8.5 in the rear. I'm running the factory jets. I'm planning on putting powervalve protection in both the front and the rear, but that still doesn't explain why it backfires from time to time. Am i running to light of powervalves? I have always ran carters and found this old carb, rebuilt it. My BBC loves it. I'm just on a learning curve here. Any help would be appreciated. Thanks

djracer · 08-09-2011, 03:10 PM

What jets are in it?
Posted via Mobile Device

Marv D · 08-09-2011, 06:25 PM

Did the 3310 come with a PV in the rear in stock form???? I'm suspectin someone has 'built' a carb out of parts which is always a dangerous thing unless you KNOW exactly what your doing.

Here's the Holley .pdf for the 3310 and calls for a #21 metering plate or 75 jets in the rear, with 67 jets in the primary with a 6.5 PV. No expert on the 3310 for sure but makes me suspect secondaries didn't have a PV and this is not the right secondary metering plate.

http://www.holley.com/data/Products/...199R9934-3.pdf

I do know in stock form the 3310 was a VERY decent street carb.

cpetersen · 08-09-2011, 07:49 PM

This one has the original metering blocks they are not plates. 76 rears and 72 fronts. With a 25 nos. I'm wondering if the pump on the front is set to lean that causes backfires to. Yeah original 780's had 2 pv's. It's good learning curve. I can't believe how many different setting there are. Truelly a performance carb. The carb guy i was asking about put the protection in it offered me $350. for it straight up. The way the economy is the guy i bought it from needed the money, i payed 125 for it. I put a kit in it for about $50.00 it runs like a champ. It just backfires from time to time. Also i don't have a vacuum gauge, i might have to light of pv's in it? The at the speed shop pulled the number for the stock setting they were 6.5 and 8.5. But if i'm pulling 12 inches i should put in 8.5 and 10.5. Any thoughts?

djracer · 08-09-2011, 10:12 PM

I think the jets should be more square.

**Captainfab** · 08-09-2011, 11:34 PM

You have your power valves backwards. The higher hg power valve should be on the primary side. The stock setup for a 3310-1 is primary jets #72's, secondary jets #76's. Primary PV is a 10.5 and the secondary PV is a 8.5

At the very least, I would switch your power valves around and see if that helps. I have the same carb on a 454 that pulls 11-12 hg at idle. I have a 9.5 PV on the primary side, but I don't remember what is in the secondary side.

cpetersen · 08-10-2011, 05:51 AM

Thanks we will give it a run.

cpetersen · 08-10-2011, 10:17 PM

Thanks for the advise guys. Silly thing is i put it back together like i took it apart. lol Glad i ask.

GASoline71 · 08-15-2011, 10:28 AM

You sure it's a 3310? A 3310 in "original" form would not have a metering block in the rear and have a metering plate (4160 style) and is 750cfm. Then add a metering block kit for the rear to make it a 4150 style carb. The secondary metering block kits don't have a power valve in them. So it sounds like the metering block in the rear is just a metering block from the front of another carb?

Unless this carb is highly modified beyond what I'm understanding. I'm no "expert" but have played with 3310's for many years.

Gary

Marv D · 08-15-2011, 11:50 AM

That's what I thought too Gary but they came in both flavors. Once I dug deep I find a listing for them with the secondary metering plate, AND the standard 4150 style metering block. Apparently even more had the block and a PV than the plate. Just the luck of what I've ran across / remembered in the ones I've messed with. Funny thing is,, I have a 'pair' of 3310's Patrick 'fixed up' for a street tunnelram sitting in boxes on a shelf. I had opened them up to make sure they were clean and dry (wipe the gaskets with vasaline) before setting them on the shelf and just assumed Patrick had modified them with a secondary block, jets and PV.

GASoline71 · 08-15-2011, 02:19 PM

Thanks Marv... ya know... I've heard of cats runnin' the PV in the rear block as well. What's the benefit to it if there is one? I've never done it. Always just had the one in the stock front block.

Gary

Marv D · 08-15-2011, 09:08 PM

Man,, your asking the WRONG cat about that!!! I order my carbs from Patrick at Prosystems,, then stuff a wide-band o2 in each header to see if I've screwed anything up between the time he wet flowed it, to the time I bolt it on LOL. I mean I'll change a jet to keep the A/F in the power zone,, but anything else is

.

Patrick is a mechanical engineer with a proficiency in hydraulics (Air is a liquid,, fuel is a liquid, talk about a guy seeking a education in his passion!!!)

ANd that's all I NEED to know about carburators LOL. Anything more and I just

**Captainfab** · 08-15-2011, 11:33 PM

The original 3310, the dash 1 was a 4150 style with a secondary metering block and a secondary power valve. The 3310-2 and sunsequent models were of the 4160 style and had just the metering plate on the secondary side. As for the advantage of running a secondary power valve, I'm not really sure on that. I'm sure prostreetC-10 will be able to answer that question

GASoline71 · 08-19-2011, 11:47 PM

I learned some new stuff about the 3310's today. Great posts!

I have a carb guru in Tacoma, WA myself named. I've messed with them enough to be dangerous, and then he usually "fixes" my "work" on the carbs. I get them from him nowadays and bolt them on and go. Good to have a cat like that in your back pocket!

Gary

cpetersen · 08-20-2011, 10:04 AM

Quote:

Originally Posted by djracer

I think the jets should be more square.

What do you mean by more square? Is there a trick to adjusting the accelerator pump?

**bigsnookmaster** · 08-20-2011, 12:50 PM

Quote:

Originally Posted by Marv D

Man,, your asking the WRONG cat about that!!! I order my carbs from Patrick at Prosystems,, then stuff a wide-band o2 in each header to see if I've screwed anything up between the time he wet flowed it, to the time I bolt it on LOL. I mean I'll change a jet to keep the A/F in the power zone,, but anything else is

.

Patrick is a mechanical engineer with a proficiency in hydraulics (Air is a liquid,, fuel is a liquid, talk about a guy seeking a education in his passion!!!)

ANd that's all I NEED to know about carburators LOL. Anything more and I just

Patrick at Pro Systems is truly a good guy, and really knows how to build a carb!

BigDan3131 · 08-20-2011, 07:59 PM

Quote:

Originally Posted by GASoline71

I learned some new stuff about the 3310's today. Great posts!

I have a carb guru in Tacoma, WA myself named. I've messed with them enough to be dangerous, and then he usually "fixes" my "work" on the carbs. I get them from him nowadays and bolt them on and go. Good to have a cat like that in your back pocket!

Gary

Do you have a phone number or business name? I don't want to send mine out to Sean Murphy if we have one local who is just as good.

djracer · 08-21-2011, 01:08 AM

Quote:

Originally Posted by cpetersen

What do you mean by more square? Is there a trick to adjusting the accelerator pump?

By more Square I mean front and rear should be closer to the same Jet.

cpetersen · 08-21-2011, 10:30 AM

Ok thanks. I also need to find someone who has one of those old fashion sun scopes here in PHX. Nobody i know has one, or knows how to use it. lol

GASoline71 · 08-21-2011, 03:36 PM

Quote:

Originally Posted by BigDan3131

Do you have a phone number or business name? I don't want to send mine out to Sean Murphy if we have one local who is just as good.

I do... can I post it here? Or do I need to send you a PM with the name and number. He's been doin' Holley's and drag race engines since the 60's.

Gary

08-09-2011, 11:28 AM	#1
cpetersen Registered User Join Date: Feb 2010 Location: mesa az Posts: 211	Holley question I have a 3310-1 which is a 780, metering blocks and 2 powervalves. I'm still having a occasionial backfire through the carb. And only when you are just giving it gas. Once every 2 weeks. Well it pops one or both powervalves everytime. I'm running a 6.5 in the front and a 8.5 in the rear. I'm running the factory jets. I'm planning on putting powervalve protection in both the front and the rear, but that still doesn't explain why it backfires from time to time. Am i running to light of powervalves? I have always ran carters and found this old carb, rebuilt it. My BBC loves it. I'm just on a learning curve here. Any help would be appreciated. Thanks

08-09-2011, 06:25 PM	#3
Marv D Registered Truck Offender Join Date: May 2008 Location: hells training ground (aka Ariz) Posts: 3,118	Re: Holley question Did the 3310 come with a PV in the rear in stock form???? I'm suspectin someone has 'built' a carb out of parts which is always a dangerous thing unless you KNOW exactly what your doing. Here's the Holley .pdf for the 3310 and calls for a #21 metering plate or 75 jets in the rear, with 67 jets in the primary with a 6.5 PV. No expert on the 3310 for sure but makes me suspect secondaries didn't have a PV and this is not the right secondary metering plate. http://www.holley.com/data/Products/...199R9934-3.pdf I do know in stock form the 3310 was a VERY decent street carb. __________________ Still playin with trucks, even at my age! When you're dead, it's only a problem for the people around you, because you don't know you're dead. .....It's kinda the same when your STUPID. I just did my taxes and reviewed my SS statement. Thanks to the current administration it looks like I will only have to work till noon on the day of my funeral.

08-09-2011, 07:49 PM	#4
cpetersen Registered User Join Date: Feb 2010 Location: mesa az Posts: 211	Re: Holley question This one has the original metering blocks they are not plates. 76 rears and 72 fronts. With a 25 nos. I'm wondering if the pump on the front is set to lean that causes backfires to. Yeah original 780's had 2 pv's. It's good learning curve. I can't believe how many different setting there are. Truelly a performance carb. The carb guy i was asking about put the protection in it offered me $350. for it straight up. The way the economy is the guy i bought it from needed the money, i payed 125 for it. I put a kit in it for about $50.00 it runs like a champ. It just backfires from time to time. Also i don't have a vacuum gauge, i might have to light of pv's in it? The at the speed shop pulled the number for the stock setting they were 6.5 and 8.5. But if i'm pulling 12 inches i should put in 8.5 and 10.5. Any thoughts?

08-09-2011, 10:12 PM	#5
djracer Registered User Join Date: Feb 2001 Location: Wetumpka, Al, U.S. Posts: 8,892	Re: Holley question I think the jets should be more square. __________________ Kevin Special Thanks to All who have helped on the TRUCK! My Pass Time Show http://s129.photobucket.com/albums/p...Chapter1-0.mp4 So Far my best Times are: Motor only: 6.44 1/8 @ 104.13 10.39 1/4 @ 125.83 Nitrous Times: 5.785 1/8 @ 118.65 with a 1.336 60ft 9.168 1/4 @ 142.58 with a 250 shot dead out of the hole!

08-09-2011, 11:34 PM	#6
Captainfab 60-66 Nut Join Date: Mar 2007 Location: Coeur d'Alene, Idaho Posts: 23,252	Re: Holley question You have your power valves backwards. The higher hg power valve should be on the primary side. The stock setup for a 3310-1 is primary jets #72's, secondary jets #76's. Primary PV is a 10.5 and the secondary PV is a 8.5 At the very least, I would switch your power valves around and see if that helps. I have the same carb on a 454 that pulls 11-12 hg at idle. I have a 9.5 PV on the primary side, but I don't remember what is in the secondary side. __________________ Power Steering Box Adapter Plates For Sale HERE Power Brake Booster Adapter Brackets For Sale '63-'66 HERE and '67-'72 HERE and '60-'62 HERE and "60-'62 with clutch HERE Rear Disc Brake Brackets For Sale. Impala SS calipers HERE Camaro Calipers HERE D52 Calipers HERE 6 Lug HERE Hydroboost Mounting Plates HERE

08-09-2011, 03:10 PM	#2
djracer Registered User Join Date: Feb 2001 Location: Wetumpka, Al, U.S. Posts: 8,892	Re: Holley question What jets are in it? Posted via Mobile Device __________________ Kevin Special Thanks to All who have helped on the TRUCK! My Pass Time Show http://s129.photobucket.com/albums/p...Chapter1-0.mp4 So Far my best Times are: Motor only: 6.44 1/8 @ 104.13 10.39 1/4 @ 125.83 Nitrous Times: 5.785 1/8 @ 118.65 with a 1.336 60ft 9.168 1/4 @ 142.58 with a 250 shot dead out of the hole!

08-10-2011, 05:51 AM	#7
cpetersen Registered User Join Date: Feb 2010 Location: mesa az Posts: 211	Re: Holley question Thanks we will give it a run.

08-10-2011, 10:17 PM	#8
cpetersen Registered User Join Date: Feb 2010 Location: mesa az Posts: 211	Re: Holley question Thanks for the advise guys. Silly thing is i put it back together like i took it apart. lol Glad i ask.

08-15-2011, 11:50 AM	#10
Marv D Registered Truck Offender Join Date: May 2008 Location: hells training ground (aka Ariz) Posts: 3,118	Re: Holley question That's what I thought too Gary but they came in both flavors. Once I dug deep I find a listing for them with the secondary metering plate, AND the standard 4150 style metering block. Apparently even more had the block and a PV than the plate. Just the luck of what I've ran across / remembered in the ones I've messed with. Funny thing is,, I have a 'pair' of 3310's Patrick 'fixed up' for a street tunnelram sitting in boxes on a shelf. I had opened them up to make sure they were clean and dry (wipe the gaskets with vasaline) before setting them on the shelf and just assumed Patrick had modified them with a secondary block, jets and PV. __________________ Still playin with trucks, even at my age! When you're dead, it's only a problem for the people around you, because you don't know you're dead. .....It's kinda the same when your STUPID. I just did my taxes and reviewed my SS statement. Thanks to the current administration it looks like I will only have to work till noon on the day of my funeral.

08-15-2011, 09:08 PM	#12
Marv D Registered Truck Offender Join Date: May 2008 Location: hells training ground (aka Ariz) Posts: 3,118	Re: Holley question Man,, your asking the WRONG cat about that!!! I order my carbs from Patrick at Prosystems,, then stuff a wide-band o2 in each header to see if I've screwed anything up between the time he wet flowed it, to the time I bolt it on LOL. I mean I'll change a jet to keep the A/F in the power zone,, but anything else is . Patrick is a mechanical engineer with a proficiency in hydraulics (Air is a liquid,, fuel is a liquid, talk about a guy seeking a education in his passion!!!) ANd that's all I NEED to know about carburators LOL. Anything more and I just __________________ Still playin with trucks, even at my age! When you're dead, it's only a problem for the people around you, because you don't know you're dead. .....It's kinda the same when your STUPID. I just did my taxes and reviewed my SS statement. Thanks to the current administration it looks like I will only have to work till noon on the day of my funeral.

08-15-2011, 11:33 PM	#13
Captainfab 60-66 Nut Join Date: Mar 2007 Location: Coeur d'Alene, Idaho Posts: 23,252	Re: Holley question The original 3310, the dash 1 was a 4150 style with a secondary metering block and a secondary power valve. The 3310-2 and sunsequent models were of the 4160 style and had just the metering plate on the secondary side. As for the advantage of running a secondary power valve, I'm not really sure on that. I'm sure prostreetC-10 will be able to answer that question __________________ Power Steering Box Adapter Plates For Sale HERE Power Brake Booster Adapter Brackets For Sale '63-'66 HERE and '67-'72 HERE and '60-'62 HERE and "60-'62 with clutch HERE Rear Disc Brake Brackets For Sale. Impala SS calipers HERE Camaro Calipers HERE D52 Calipers HERE 6 Lug HERE Hydroboost Mounting Plates HERE

08-21-2011, 10:30 AM	#19
cpetersen Registered User Join Date: Feb 2010 Location: mesa az Posts: 211	Re: Holley question Ok thanks. I also need to find someone who has one of those old fashion sun scopes here in PHX. Nobody i know has one, or knows how to use it. lol



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