Brand New Holley carb question.. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Jefe · 02-24-2005, 11:40 PM

Brand New Holley 600 cfm vacume secondaries mechanical choke holley 4160 carb. Hooked it up...everything went great..fired right up idles fine rev's nice...but no secondaries!? I can manually open them by slightly pushing up the vacume secondarie rod on the passenger side of the carb...but they wont open by themselves when throttled. Probably going to take the carb back tommorow and swap it for a new one...but wondering what everyone's thoughts were...thanks!!!

Douglas.

draino76 · 02-24-2005, 11:50 PM

depending on how the carb is set up you may not get them to open unless the engine is at wot or under a load. I know we have got some holley people here that can help you out.

454_72_4X4 · 02-24-2005, 11:59 PM

Vacuum secondaries won't open until needed. Are you trying to make them open without driving the truck? IE sitting in the driveway/shop? Depending on your setup they should (might/mightnot), just start to open about the time you think you'll be picking up pieces with a broom.
You might also need a different secondary spring too. If you determine you need a lighter spring, do yourself a favor and buy the quick change kit if your carb doesn't already have it. The quick change kit is worth more than the carb if ya dont have it!

cableguy0 · 02-25-2005, 12:01 AM

they will not open until the engine is under load and loses its vaccum theres nothing wrong with the carb at the most you will have to change the secondary spring to make them open sooner or later but more than likely it will be ok out of the box

Jefe · 02-25-2005, 12:06 AM

True. Don't see the spring being too stiff but you could be right..I also drove the truck around and still no secondaries. The motor is a 307/268 comp cam 454/454 lift (forgot the other specs)/edelbrock preformer/mallory HEI/194 150 valves/flat top pistons/long tube headers. Used to run great until by carter I had on there crapped out on me..(it was really old and rebuild several times)I have always had great luck with Holleys so I figured I would put one on my daily driver ...

Douglas.

cableguy0 · 02-25-2005, 12:08 AM

i bet the spring is too stiff go to a lighter spring and i bet they will open up

454_72_4X4 · 02-25-2005, 12:11 AM

With a 307 you'll probaby need a lighter spring for sure.

jhow66 · 02-25-2005, 01:18 AM

Here is a way to check if they are opening while driving--take a paper clip and attach it to the rod of the vacumn pod (bend it so that it will not flip off) up aganist the bottom of the pod. When the rod moves up it will push the clip down the amount it opens. Also they will not open all at once but only as the engine can use the extra air. In other words you will not feel a "lurch" if the secondarys are working right but a gradual increase in power.

**1970 CST Short Wide** · 02-25-2005, 11:53 AM

I have this one for sale 600 CFM List #4776 Double Pump, Duel Feed, Mech Secondary

$225 includes shipping

RON WOODGEARD · 02-25-2005, 07:18 PM

In most cases you will not even notice that the secondaries are kicking in. "jhow" has a great way to check it...

There is a vacuum to mechanical conversion kit available..

tom hand · 02-25-2005, 08:17 PM

Quote:

Originally Posted by RON WOODGEARD

In most cases you will not even notice that the secondaries are kicking in.

..

If you are used to a Q-jet you will think a holley is not "kicking in"....it just not have the kick of a q-jet....it is smoother...can't beat a spead-bore

mooneyes · 02-25-2005, 08:23 PM

...i have never owned a vaccum sec. holley that the sec. worked..i always put a small bolt lock washer and nut in the slot where the rod comes back to open the rear butterflys...then they open like a q-jet

02-24-2005, 11:40 PM	#1
Jefe Registered User Join Date: Jul 2000 Location: Chandler, Arizona, USA Posts: 299	Brand New Holley carb question.. Brand New Holley 600 cfm vacume secondaries mechanical choke holley 4160 carb. Hooked it up...everything went great..fired right up idles fine rev's nice...but no secondaries!? I can manually open them by slightly pushing up the vacume secondarie rod on the passenger side of the carb...but they wont open by themselves when throttled. Probably going to take the carb back tommorow and swap it for a new one...but wondering what everyone's thoughts were...thanks!!! Douglas. __________________ -1968 Chevy SWB = Frame Off/383/Muncie Car 4 speed -1968 Chevy SWB = numbers matching 307/Truck 4 speed. -1966 Chevy II = 2 door No Post/130,000 Orig miles/230 6cyl/powerglide/Vintage AC -1972 Chevy Nova = 2 door/412 Small Block -1927 Ford Roadster = Homebuilt/widened 8"/350/ Custom Everything.

02-24-2005, 11:50 PM	#2
draino76 FUJIMO Join Date: Dec 2004 Location: South Dakota Posts: 127	depending on how the carb is set up you may not get them to open unless the engine is at wot or under a load. I know we have got some holley people here that can help you out. __________________ IF IT DON'T GO--CHROME IT!! I dont mind confusion, I create it!

02-24-2005, 11:59 PM	#3
454_72_4X4 Registered User Join Date: Apr 2004 Location: N.E. MO Posts: 1,749	Vacuum secondaries won't open until needed. Are you trying to make them open without driving the truck? IE sitting in the driveway/shop? Depending on your setup they should (might/mightnot), just start to open about the time you think you'll be picking up pieces with a broom. You might also need a different secondary spring too. If you determine you need a lighter spring, do yourself a favor and buy the quick change kit if your carb doesn't already have it. The quick change kit is worth more than the carb if ya dont have it! __________________ 72 C20 4X4 454 4 speed 89 Trans Am (was) 305 TPI 700r4 93 C1500 2wd Extended cab 350 700r4 98 Sonoma (TPI outa the Trans Am) 03 Yamaha 660 Raptor 03/04 660 Raptor 07 700 Raptor 85 Honda Odyssey

02-25-2005, 12:06 AM	#5
Jefe Registered User Join Date: Jul 2000 Location: Chandler, Arizona, USA Posts: 299	True. Don't see the spring being too stiff but you could be right..I also drove the truck around and still no secondaries. The motor is a 307/268 comp cam 454/454 lift (forgot the other specs)/edelbrock preformer/mallory HEI/194 150 valves/flat top pistons/long tube headers. Used to run great until by carter I had on there crapped out on me..(it was really old and rebuild several times)I have always had great luck with Holleys so I figured I would put one on my daily driver ... Douglas. __________________ -1968 Chevy SWB = Frame Off/383/Muncie Car 4 speed -1968 Chevy SWB = numbers matching 307/Truck 4 speed. -1966 Chevy II = 2 door No Post/130,000 Orig miles/230 6cyl/powerglide/Vintage AC -1972 Chevy Nova = 2 door/412 Small Block -1927 Ford Roadster = Homebuilt/widened 8"/350/ Custom Everything.

02-25-2005, 12:08 AM	#6
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,950	i bet the spring is too stiff go to a lighter spring and i bet they will open up __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

02-25-2005, 12:01 AM	#4
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,950	they will not open until the engine is under load and loses its vaccum theres nothing wrong with the carb at the most you will have to change the secondary spring to make them open sooner or later but more than likely it will be ok out of the box __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

02-25-2005, 12:11 AM	#7
454_72_4X4 Registered User Join Date: Apr 2004 Location: N.E. MO Posts: 1,749	With a 307 you'll probaby need a lighter spring for sure. __________________ 72 C20 4X4 454 4 speed 89 Trans Am (was) 305 TPI 700r4 93 C1500 2wd Extended cab 350 700r4 98 Sonoma (TPI outa the Trans Am) 03 Yamaha 660 Raptor 03/04 660 Raptor 07 700 Raptor 85 Honda Odyssey

02-25-2005, 01:18 AM	#8
jhow66 Registered User Join Date: Jun 2002 Location: Knoxville Tenn. Posts: 3,058	Here is a way to check if they are opening while driving--take a paper clip and attach it to the rod of the vacumn pod (bend it so that it will not flip off) up aganist the bottom of the pod. When the rod moves up it will push the clip down the amount it opens. Also they will not open all at once but only as the engine can use the extra air. In other words you will not feel a "lurch" if the secondarys are working right but a gradual increase in power. __________________ 56 Chevy Bel-Air 2dr. HT (purchased new) 71 Chevy Cheyenne SWB PU (502HO) 65 GMC short bed step--work in progress and my gofer

02-25-2005, 11:53 AM	#9
1970 CST Short Wide Senior Moment Join Date: Mar 2002 Location: Pittsburg Ca Posts: 4,168	Go with Mech Secondarys I have this one for sale 600 CFM List #4776 Double Pump, Duel Feed, Mech Secondary $225 includes shipping Attached Images __________________ 1970 CST LS 1 6 speed Ford 9 inch Detroit Tru Track, Dakota Didgital, Vintage Air, QA1 Coil Overs Front & Rear Lots of FUN 2013 GMC PU, Oldest Son 71 GMC LWB. QA1 Suspension, Angry SB. Youngest Son 2019 GMC Diesil Dually. Youngest Son 2017 Toyota SUV Daughters car 2018 Traverse , Wife’s Ride Pittsburg Ca 94565

02-25-2005, 07:18 PM	#10
RON WOODGEARD Resident Young Old Dude ! Join Date: Jul 2001 Location: Nevada Posts: 1,948	In most cases you will not even notice that the secondaries are kicking in. "jhow" has a great way to check it... There is a vacuum to mechanical conversion kit available..

02-25-2005, 08:23 PM	#12
mooneyes Registered User Join Date: Jan 2002 Location: Slippery Rock PA USA Posts: 1,692	...i have never owned a vaccum sec. holley that the sec. worked..i always put a small bolt lock washer and nut in the slot where the rod comes back to open the rear butterflys...then they open like a q-jet __________________ Ken Lyons, Slippery rock pa 68 short step 327 t10 4 gear 72 2wd blazer project 70 lwb 305/700r driver 78 caprice project 02 cavalier D.D ( hate it!!)



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