quick fuel

[jpaz]

I checked that in my distributor also, it's been recurved. Back when I got my SA carb I made sure of all that.

 

[Stanglover]

I checked that in my distributor also, it's been recurved. Back when I got my SA carb I made sure of all that.

 That's awesome.

All a carb basically does is vaporize fuel and add air. If the rest of the stuff going on is not correct, then it stands to reason that it'll never run as it should.

 

[boilermaster]

Hey guys, I'm thinking about this carb for my 72 Mach 1 Q code. I currently have a 770 Street Avenger on now, but not real happy with it. I've had it for about 3 years now, and I'm still having the same troubles as others. I just can't seem to get it dialed in right. I thought I had it running decent, but it's way to lean. I'm getting tired of messing with it, and you can see that it's cheaply made. It's already leaking from the throttle plate and the butterfly shaft.

My 351 is the original Q Code block that has been rebuilt by the PO, so I don't really know exactlly what had been done. I do know it does have a larger than stock cam, but I have no details for it other than it's a non roller rocker set up. I have a Blue Thunder dual plane intake on it, C6 auto trans with 3.50 Trutrack rear end. This carb looks like it is a better made piece and more tunable. Any feedback would be greatly appreciated, Thanks https://www.holley.com/products/fuel_systems/carburetors/quick_fuel/street/ss-series/parts/SS-735-VS

jpaz,

I would ask what kind of a vacuum reading do you have @ hot idle?

That could help determine what type of cam you have.

However, after you stating that it leaks at the throttle shaft, pretty much all bets would be off.

you might as well throw it out there anyways.

Was never a fan of reading spark plugs, have found it to be ok for cruise rpm a/f and WOT, after that not so much.

my best gains with the wideband were dialing in the size of the (pvcr) power valve channel restriction and vacuum secondary opening (quick fuel adjustable) on my holley 750 sa.

the pvcr was way too rich, about 10.6/1 .

another member here clued me in on how to drill and tap the restrictor and install brass set screws with a drilled orfice, worked like a champ, was able to go to about 12.5/ 12.6 a/f

this made a major difference in how my engine pulled at wot and the adjustable vacuum pod from quick fuel was near as good.

not too shabby for a carb that had been sitting on this engine for about 10 years without running.

Boilermaster

 

[jpaz]

I think the best vacuum I could get was about 13-15 @ hot idle. I'm trying to find all my notes about my readings.

 

[Stanglover]

Hey guys, I'm thinking about this carb for my 72 Mach 1 Q code. I currently have a 770 Street Avenger on now, but not real happy with it. I've had it for about 3 years now, and I'm still having the same troubles as others. I just can't seem to get it dialed in right. I thought I had it running decent, but it's way to lean. I'm getting tired of messing with it, and you can see that it's cheaply made. It's already leaking from the throttle plate and the butterfly shaft.

My 351 is the original Q Code block that has been rebuilt by the PO, so I don't really know exactlly what had been done. I do know it does have a larger than stock cam, but I have no details for it other than it's a non roller rocker set up. I have a Blue Thunder dual plane intake on it, C6 auto trans with 3.50 Trutrack rear end. This carb looks like it is a better made piece and more tunable. Any feedback would be greatly appreciated, Thanks https://www.holley.com/products/fuel_systems/carburetors/quick_fuel/street/ss-series/parts/SS-735-VS

jpaz,

I would ask what kind of a vacuum reading do you have @ hot idle?

That could help determine what type of cam you have.

However, after you stating that it leaks at the throttle shaft, pretty much all bets would be off.

you might as well throw it out there anyways.

Was never a fan of reading spark plugs, have found it to be ok for cruise rpm a/f and WOT, after that not so much.

my best gains with the wideband were dialing in the size of the (pvcr) power valve channel restriction and vacuum secondary opening (quick fuel adjustable) on my holley 750 sa.

the pvcr was way too rich, about 10.6/1 .

another member here clued me in on how to drill and tap the restrictor and install brass set screws with a drilled orfice, worked like a champ, was able to go to about 12.5/ 12.6 a/f

this made a major difference in how my engine pulled at wot and the adjustable vacuum pod from quick fuel was near as good.

not too shabby for a carb that had been sitting on this engine for about 10 years without running.

Boilermaster

 Interesting comments there Boilermaster. What I really need to do is borrow a friends af meter. Plug reading only goes so far I agree. Still I'm getting mighty temped to go buy a better carb after reading all the sour comments on SA's Hmm,we'll see!!

 

[Stanglover]

I think the best vacuum I could get was about 13-15 @ hot idle. I'm trying to find all my notes about my readings.

 Just to mention that all my results are on an engine with 17-18" Hg vacuum hot. I forgot to say that before.  No lumpy cam for me!!

 

[jpaz]

Ya mine definitely has a bit of a lumpy cam.

 

[jpaz]

Now that I'm thinking more about it, pretty sure my vacuum was at 13-14" @ hot idle.

 

[jpaz]

Now they have them in blue. https://www.ebay.com/itm/QUICK-FUEL-SS-735-VS-735-CFM-GAS-VACUUM-W-CHOKE-BLUE-COLOR-COMBO-WITH-GAUGE/382409161491?hash=item59095cbb13:g:KLwAAMXQwKdRdQCN:sc:UPSGround!48094!US!-1&vxp=mtr

 

[TommyK]

The only thing I see I don't like on that QF carb linked, is it does not have the quick change vacuum secondary spring cap.

That's because the secondary opening rate is adjusted via an external screw. No need to remove the cap and change springs.

 

[boilermaster]

I have one O2 monitor in my gauge cluster and another in my tool box that I use to tune other peoples hot rods, alligator clips on the electrical leads, all one needs to do is install bung in the pipe or header collector.

With some of the holley's there is only so much you can do, due to some not having removable bleeds.

have not figured out how to improve idle transition yet without installing aftermarket metering blocks.

it's not so much about what the O2 numbers are, but more about what the engine likes.

Boilermaster

 

[Stanglover]

The only thing I see I don't like on that QF carb linked, is it does not have the quick change vacuum secondary spring cap.

That's because the secondary opening rate is adjusted via an external screw. No need to remove the cap and change springs.

Ah! I did not know that. I have not yet done extensive research on various QF carbs as a new carb for me is still on the maybe someday list.

Thanks for that nugget.

Geoff.

 

[jpaz]

I talked with a guy from here today, and this was his recommendation. He told me to get a couple vacuum readings and he could get pretty close on my cam specs. He guaranteed me this carb would work way better on my car. Really sounds like they know their stuff. I'm pretty sure I know what I'm doing with my tax refund now! https://www.ebay.com/itm/Quick-Fuel-735-cfm-Carburetor-HR-735-VS-ELECTRIC-VACUUM-SECONDARY-CUSTOM-FREE/201526031087?epid=1158634422&hash=item2eebe332ef:g:CR4AAOSwPc9WxkdO&vxp=mtr

 

[Ron Tanzi]

When I built my 351C in 2002, with specs as follows : 2 barrel heads with stainless valves, Edelbrock performer 4 barrel intake, TRW forged flat top pistons, ARP bolts, dynamic balance and a Comp cams version of the D1ZZ CJ cam. When I was dynoing the engine I tried moving up from my Holley 4160 600 cfm that I converted to a 4150 with the secondary metering block kit. I decided to try the 770 street Avenger and after much tuning and not finding satisfaction (flat spots,bogging) I went back to my original carb which I am using to this day without issues. My engine made a bit over 300 hp @4600 rpm and 358 lbft of torque @ 3600 rpm with my original 600 cfm carb. I returned the Avenger to Summit for a full credit. As far as idle air issues with the Cleveland goes, On Holleys you can adjust the secondary plate opening angle with the stop screw. The down side is that you must remove the carb to access the screw. This means you have take a shot and estimate until you get to the point that you are no longer exposing the primary side throttle plate transfer slots @ idle. I prefer the aforementioned to drilling holes in my throttle plates.

Ron

 

[boilermaster]

When I built my 351C in 2002, with specs as follows :  2 barrel heads with stainless valves, Edelbrock performer 4 barrel intake, TRW forged flat top pistons, ARP bolts, dynamic balance and a Comp cams  version of the D1ZZ CJ cam. When I was dynoing the engine I tried moving up from my Holley 4160 600 cfm that I converted to a 4150 with the secondary metering block kit.  I decided to try the 770 street Avenger and after much tuning and not finding satisfaction (flat spots,bogging) I went back to my original carb which I am using to this day without issues. My engine made a bit over 300 hp @4600 rpm and 358 lbft of torque @ 3600 rpm with my original 600 cfm carb. I returned the Avenger to Summit for a full credit. As far as idle air issues with the Cleveland goes, On Holleys you can adjust the secondary plate opening angle with the stop screw. The down side is that you must remove the carb to access the screw. This means you have take a shot and estimate until you get to the point that you are no longer exposing the primary side throttle plate transfer slots @ idle. I prefer the aforementioned to drilling holes in my throttle plates.

Ron

Ron,

I have had to actually had to drill primary plates once, 496 olds stroker.

usually replace the slotted screw that Holley provides with a hex headed set screw .

if the carb is installed , one can use feeler gauge between the stop then one only has to remove the carb once.

Whole nother can of worms on the transfer slots, wish they would have put the front screw in from the bottom like the rear is, so many with over rich idles and so little time.

Boilermaster

 

[Ron Tanzi]

When I built my 351C in 2002, with specs as follows :  2 barrel heads with stainless valves, Edelbrock performer 4 barrel intake, TRW forged flat top pistons, ARP bolts, dynamic balance and a Comp cams  version of the D1ZZ CJ cam. When I was dynoing the engine I tried moving up from my Holley 4160 600 cfm that I converted to a 4150 with the secondary metering block kit.  I decided to try the 770 street Avenger and after much tuning and not finding satisfaction (flat spots,bogging) I went back to my original carb which I am using to this day without issues. My engine made a bit over 300 hp @4600 rpm and 358 lbft of torque @ 3600 rpm with my original 600 cfm carb. I returned the Avenger to Summit for a full credit. As far as idle air issues with the Cleveland goes, On Holleys you can adjust the secondary plate opening angle with the stop screw. The down side is that you must remove the carb to access the screw. This means you have take a shot and estimate until you get to the point that you are no longer exposing the primary side throttle plate transfer slots @ idle. I prefer the aforementioned to drilling holes in my throttle plates.

Ron

Ron,

I have had to actually had to drill primary plates once, 496 olds stroker.

usually replace the slotted screw that Holley provides with a hex headed set screw .

if the carb is installed , one can use feeler gauge between the stop then one only has to remove the carb once.

Whole nother can of worms on the transfer slots, wish they would have put the front screw in from the bottom like the rear is, so many with over rich idles and so little time.

Boilermaster

I agree with you about the fact that there Are times you have to drill the plates. But usually that is needed with a radical cam. It would have been nice as you said if they made the secondary adjustment easier to get to. And yes I have used the feeler gauge method on the secondary plate adjustment (for a baseline) and the accelerator pump over ride spring adjustment before. I guess we live with the fact that carburetors can be fickle little somethings> LOL. I still will never go with EFI on my Mustang.  EFI has it's many virtues (and I fix them all the time) but I will always need to still have something with a carb. That is what I grew up with. 

Best,Ron

 

[Omie01]

+1 on no EFI. I also grew up with carbs and love them. The only downside I ever see is the idle not being perfectly smooth, other than that I can't justify the cost vs reward when it comes to old motors. If I were to buy a car with it already installed though I would keep it!! All that being said, the Pro Systems I have only has 1 setting that it likes for my car so its VERY clear where the proper tune is for my engine. I'm very happy to live in a time where you can have somebody build a carb specific for your engine. I don't mind tweaking and tuning stuff, but there is something to be said for the piece of mind I get knowing my engine is running 100%.

 

[jpaz]

I agree with you Omie01, I can't wait to get a new carb that I can do some tweaking to suit my engine. I shouldn't have to rebuild and modify a new carb for my application, it's not a radical engine build by any means. And after learning more about the SA carbs, I wish I would have done more research on it. Oh well, live and learn & learn some more!

I am ordering a new QFT HR 735 VS that will be set up and should be pretty close for my car. They 7 different engine dyno rooms that they use and have 2 different 351 Cleveland's set up, 1 for street and 1 for race. So for 460 bucks, which is only 20 more than I paid for the SA, I'm going to get a much more tunable carb that will work better on my engine.

If I ever make any changes to my motor in the future, they will help me with any tuning issues if I need it. Can't wait!

 

[Stanglover]

I agree with you Omie01, I can't wait to get a new carb that I can do some tweaking to suit my engine. I shouldn't have to rebuild and modify a new carb for my application, it's not a radical engine build by any means. And after learning more about the SA carbs, I wish I would have done more research on it. Oh well, live and learn & learn some more!

I am ordering a new QFT HR 735 VS that will be set up and should be pretty close for my car. They 7 different engine dyno rooms that they use and have 2 different 351 Cleveland's set up, 1 for street and 1 for race. So for 460 bucks, which is only 20 more than I paid for the SA, I'm going to get a much more tunable carb that will work better on my engine.

If I ever make any changes to my motor in the future, they will help me with any tuning issues if I need it. Can't wait!

 John, That's very interesting news. Please keep me/us up on how it works in the real world. I'm with you now, wishing I'd done a bit more research prior to buying the 670SA, but at the time, I needed a new carb. It was either buy what I could get or not drive the car. I will have to continue with the SA for this year now, limited dollars, but next season, funds available and hopefully a more friendly dollar exchange, I'll follow your lead. Perhaps you could either post the full contact information, or PM me.

Thanks for your input, much appreciated.

Geoff.

 

[Ron Tanzi]

+1 on no EFI. I also grew up with carbs and love them. The only downside I ever see is the idle not being perfectly smooth, other than that I can't justify the cost vs reward when it comes to old motors. If I were to buy a car with it already installed though I would keep it!! All that being said, the Pro Systems I have only has 1 setting that it likes for my car so its VERY clear where the proper tune is for my engine. I'm very happy to live in a time where you can have somebody build a carb specific for your engine. I don't mind tweaking and tuning stuff, but there is something to be said for the piece of mind I get knowing my engine is running 100%.

 The crap gas we are forced to use makes things more challenging as well (ethanol sucks). I have to say I trust a carb over a very expensive after market bolt on EFI system. Your carb has to be pretty screwed up to leave you stranded and you might be able to fix it in the field to the point that you won't need a tow. If your EFI system blows an ECU or a critical sensor and then you are stuck. I am a mechanic and work on modern cars and for the most part all the manufactures have reliable systems with built in fail safes that will keep going. I am not as sure about the after market products. I remember the days of people carrying a spare set of points or a ballast resistor (Mopar guys) in the glove compartment LOL.

Ron