Question: Holly help

[gmjunkie]

Next, I have had no problems with the carburetor before, and I'm not sure that I have problems now.

Oh believe me,if it's a "HOLLEY" at some point there are going to be problems!!~!

 

[65TripleBlack]

Oh believe me,if it's a "HOLLEY" at some point there are going to be problems!!~!

As opposed to a holly, which I have in my yard.

Quick Fuel is a Holley clone, but much finer craftsmanship. Made and assembled in Bowling Green, KY, with EXCELLENT customer support.

World of difference between a Holley and a QF. Besides the inferior quality of the product, Holley customer service is very poor.

 

[RestoCreations]

I have the quick fuel BD750 on a 500hp 363 Ford Racing Stroker crate engine and it is the best carb I have used yet. However, I highly doubt a 750cfm would be appropriate for any 327.

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I have used the Quick fuel SL600(air cleaner must be modified) and the quick fuel BD-1957 on 327 and stock 427/390 engines with great success. The BD-1957 is almost a direct bolt on replacement for the 2818-1. Not trying to get off topic, but when set up properly, quick fuel carburetors really can't be beat.

Unusual Activity Detected - Free Shipping on Orders Over $99 at Summit Racing

Unusual Activity Detected - Free Shipping on Orders Over $99 at Summit Racing

Not sure why it says unusual activity detected. Those are links to the carburetors on summit racings site.

 

[65TripleBlack]

I have the quick fuel BD750 on a 500hp 363 Ford Racing Stroker crate engine and it is the best carb I have used yet. However, I highly doubt a 750cfm would be appropriate for any 327.

Unusual Activity Detected - Free Shipping on Orders Over $99 at Summit Racing


I have used the Quick fuel SL600(air cleaner must be modified) and the quick fuel BD-1957 on 327 and stock 427/390 engines with great success. The BD-1957 is almost a direct bolt on replacement for the 2818-1. Not trying to get off topic, but when set up properly, quick fuel carburetors really can't be beat.

Unusual Activity Detected - Free Shipping on Orders Over $99 at Summit Racing

Unusual Activity Detected - Free Shipping on Orders Over $99 at Summit Racing

Not sure why it says unusual activity detected. Those are links to the carburetors on summit racings site.

Does that include a 475 horsepower 327, like mine? Did you read my post #20?

 

[Hib Halverson]

Why would a double pumper run rich on the street? Is the secondary accel pump discharged like a fuel injector nozzle even though the secondary butterflies aren't being opened?

The, idle and idle transfer circuits in double-pumpers are calibrated for racing engines with "big" camshafts and, thus, when bolted on a street engine or mild high-performance street engine which generate big vacuum signals, they'll run rich. You cannot compensate for that with jetting because when those circuits are supllying most of the fuel, the main circuit is barely working. Also the proportion of fuel flow though the main circuit and the power enrichment circuit is skewed towards race engines. Restricting the idle feed restrictions and changing the proportion of fuel flow though main and PE circuts are just two of the mods you have to make to run a DP on the street.

The Edelbrock Performer is higher than the old GM cast iron intakes, about 1/4" shorter than the Winters aluminum intakes used between 1962-1967. I'm not sure what constitutes a "high rise" intake? Maybe anything taller than the cast iron ones? Can you call the Performer an "almost high rise"? The Performer RPM is at least 1/2" taller than the 1962-67 Winters intakes and about 1/4" taller than the LT1 intake, so that might be called a "super high rise" intake.

The Performer is a "medium-rise" at best.

The Performer RPM and RPM Air Gap manifolds are high-rise.

The Victor Jr. and Victor are "super high rise".

 

[Hib Halverson]

Hib,
I've heard DPs are poor street carburetors. I guess I'm dating myself. However, back in the day everything from a Z28's 302, 396-375, the Corvette 396-425, and the HO 427s came with a DP Holley.

Neither the Z/28, 396/375, 396/425 or the "HO 427s" came from GM with double-pumpers. They all had dual-feed, vacuum-secondary Holleys. The only Chevrolet engines to come stock with double-pumpers were '69 second-design L88s and ZL1s, also, in 69, only, Z/28 302s did have a DSO cross-ram intake manifold that mounted two Holley DPs. The same 2x4 X-ram was available the year before but, in '68, both carbs were an odd mech. secondary, single-accel. pump unit–which must have sucked much to drive.

Back then, a DP Holley is what they came with from the factory and we drove them on the streets.

Again, that's not correct.

I didn't have any issues running them; even center shooters on a tunnel ram. Or the gear drives on the choke side.

With all due respect...yes you did. You just didn't know it at the time. Also, everyone's concept of "drivability" varies quite widely as well as differing by period.

By your mention of a wide band O2 sensor; is it modern engines that have issues? I do know, back in the day we sure didn't. Is this a modern thing?

Obviously, it's a "modern" thing as WBO2Ses priced for DIYs did not exist until fairly recently. Read this story elsewhere on the CAC about tuning a DP for the street. That could not have done without a wideband.

 

[Hib Halverson]

I have a Quick Fuel 750 dual inlet race carb on my 327. Doesn't have a choke horn. One pump cold and the engine starts and runs immediately with a turn of the key (say, 1/4 of one crank), with some feathering of the throttle for the first 20 seconds until things warm a tad.

Plugs run perfect color, no fuel smell, no rich exhaust. WOT from a dead stop in 1st gear and the engine roars and the tires go up in smoke and revs hit the limiter immediately. No hesitation, no bog. Mash to WOT in 5th gear @ 2000 RPM and the engine pulls smoothly and steadily with zero hesitation.

What's not streetable about that? Plus 20 plus MPG @ 75 MPH with the 5 speed.

If a carb is properly tuned with suitable jet, power valve, and air bleed sizes, then all will be well. This issue about mechanical secondaries not being streetable is hogwash.

As mentioned above, SIZE is important. A mild 327 or 350 will be very happy with a 600-650 single feed carb because of the small throttle bores. A 750, single or dual feed can be appropriate as well, because the 750 uses downleg boosters, which make it more sensitive and responsive to low manifold vacuum than a 600-650 which use straight leg boosters.

At what rpms does your 327 make peak power and peak torque. Also, what's the rev limiter set at?

 

[65TripleBlack]

At what rpms does your 327 make peak power and peak torque. Also, what's the rev limiter set at?

The rev limiter is set to 7750 RPM.

 

[Hib Halverson]

Looks like about 425-hp SAE at 6600 rpm or right at 500-hp SAE at the crank. That's a pretty stout 327, for sure.

Curious....if peak power is 6600 why the 7750 rpm rev limiter...are you planning additional mods? What kind of valvetrain hardware do you have such that the valvetrain is stable at 7700?

Finally, the 20-mph figure is outstanding. I'm interested to know about the car's weight, trans and axle ratio.

 

[65TripleBlack]

Looks like about 425-hp SAE at 6600 rpm or right at 500-hp SAE at the crank. That's a pretty stout 327, for sure.

Curious....if peak power is 6600 why the 7750 rpm rev limiter...are you planning additional mods? What kind of valvetrain hardware do you have such that the valvetrain is stable at 7700?

Finally, the 20-mph figure is outstanding. I'm interested to know about the car's weight, trans and axle ratio.

Thank you.

That version of the graph doesn't show the peak numbers; peak power is 414 RWHP @ 6564 RPM, so about 485 or so at the crank.

It uses a solid cam with a "rev kit", and modern style (low I.M.) valve springs. I'm also using 1. :1 rockers all around.

The trans is a wide ratio 5 speed, with .67:1 overdrive and a 3.70 axle; the car weighs 3350 with a full tank and driver. Cruises at about 2500 @ 80.

The reason I shift at 7250 is because of the wide ratio trans. I left some margin in the limiter, and it doesn't complain if it hits it. I have had it set at 7500 at one time, but 7750 is tolerated well if I need to shift higher than 7250.

Unfortunately, at the track, the wide ratio trans causes me to go thru the traps in 3rd gear, about 300 RPM below the shift point.

The engine makes plenty of torque as you can see and is, indeed, a fun driver.

 

[Bo Dillingham]

To All,

We seem to have gotten into discussions that are a little over my head, but I have a very simple question now;

Today I went to my local NAPA to get a rebuild kit for my Holley (4165 SB DP), which is Holley part number 37-605. The counterman said that they have an equivalent kit, so that's what I ordered. My question is whether or not a NAPA carb rebuild kit is as good as the equivalent Holley kit, or is it worth holding out for a Holley kit number 37-605?

(By the way, I did take the Vette to the local repair shop and they told me that they believe the problem is in the carb, not the ignition.)

As usual, advice is appreciated,

BoDill

 

[Bo Dillingham]

To All,

Regarding a rebuild kit for my 4165 Holley; I went to NAPA to pick up the kit that I ordered, and upon inspection it did not come with a power valve. Since that looks like a critical part, I asked about it, and they did not include one in their kit, and they couldn't get one separately. They were apologetic, and gave me my money back. From there I went to Autozone, only to find out that they cannot get the kit either.

With that, I just ordered the kit (Holey number 37-605) from Summit, and their picture of the kit includes three power valves. A couple of the reviews of the kit were spectacular, while one review said that it was a good kit and had almost all the parts. I expect to get the kit within a few days, and will try a rebuild soon. I'll let you know how it comes out, but I thought that I would tell you where it's at so far....

BoDill

 

[65TripleBlack]

Hopefully the Holley kit comes with the blue float/metering block gaskets. Do not over tighten them for risk of warping the bowls and metering block(s). You probably have a 6.5 power valve installed. Replace it with the same or 8.5 valve for fuel economy. The best way to determine which PV you need is to use a vacuum gauge while driving and check the manifold vacuum at medium throttle. You want to absolutely minimize the time that the engine is into the PV because the fuel flow increases significantly. If the engine spends too much time "in the power valve" it will foul plugs unless you use an MSD box and high powered coil.

 

[Bo Dillingham]

To All,

Since I now have two threads going, I'm going to stop using this one and put all my questions and/or information on the "Warm Engine Misses" thread so look for me there....

Thanks all,

BoDill