How to Set up & Install a 750 Speed Demon on a 350 (dial-up beware)
03-03-2004, 03:56 PM
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How to Set up & Install a 750 Speed Demon on a 350 (dial-up beware)
(Copies of this article with the photos are available by sending me an e-mail request. Size of this article in MS Word format is 288KB. V8FastCars@msn.com)
After an interesting series of posts here on the C3 Forum regarding carb sizing, one of our Forum members – “signguy" (Gary – from Florida) – asked me to do a setup on a new Speed Demon 750 for his mildly modified C3. He ordered the carb and all the parts from Summit and had it all drop shipped to me. I took the whole system, modified it, and set it up to run correctly using one of my own cars as the test bed (this 750 mechanical sec carb runs sooooo sweet on my 350…!) Here is the whole sequence to the operation:
Getting a BG Speed Demon carb set up and running right on your engine is all in the prep work: A few bench settings are required, and it’s important to use the right combination of modified parts and accessories to make the installation look good and perform properly. Here are the basic steps (these steps are also detailed in my Tech Paper, “How to Set up a BG Speed Demon.” Drop me an e-mail request for a copy of this paper: V8FastCars@msn.com):
First, set the throttle blade angles. The BG carbs (and Holley carbs, too) need to meter equal air through both primary and secondary sides of the carb at idle. This is never set correctly on an out-of-the-box carb. To do this, flip the carb upside-down and adjust the primary and secondary idle speed screws so that .020” of the transition slot is exposed on all 4 throttle blades. Use a feeler gauge to check. (After you’ve done a few of these, you can do it by eyeballing it: The transition slots are .020” wide, so you can adjust the throttles so that the exposed part of the slot appears as a square hole under the throttle blade.)
Throttle blades cracked open to show the vertical transition slots. These slots start metering fuel as you come off idle and as you go into the main discharge circuit. If too much of the slots are exposed, idle mixtures will be incorrect. .020” of the slots should be exposed below the edge of the throttle blades.
“Out-of-the-box” setting of the throttle blades shows secondary throttle closed completely – there is no exposure of the transition slot on the secondary side. Primary side had massive slot exposure to compensate for lack of adjustment on secondary side.
Correctly set throttle blade angle. .020” of the slots are exposed below the blades. Both primary and secondary throttles should be set exactly like this.
The BG carbs, and most Holleys, have only a single 3/8” vacuum port for connection of the PCV. If you’re running power brakes, you can install a “T” system like this to run PCV and brakes. I have made the “T” section short enough that it is hidden under the secondary bowl. This makes a very clean installation. Note twin vacuum nipples coming out of the side of the throttle plate: The forward nipple (right) is ported vacuum for distributor vacuum advance. The rear nipple (left) is direct manifold vacuum for vacuum accessories. You can also use direct manifold vacuum for distributor advance depending on the tuning needs of your engine – see my tuning articles discussing these concepts.
BG and Holley carbs need a reflective heat shield installed under the carb: The accelerator pump wells are close enough to the hot manifold that the fuel in the pump wells will boil after hot engine shutdown. As the fuel boils and vaporizes, it pushes fuel out the accel discharge nozzles, flooding the engine after shutdown. Holley builds a shield, but it does not fit correctly. Seen here is a modified Holley shield: I have trimmed about an inch off the forward edge so it will clear the thermostat housing. The rear edge has been trimmed forward. The right side of the shield has been cut inwards to prevent the throttle shafts from binding on the shield. The right corners have been trimmed at a 45-degree angle to clear the carb inlet line. Finally, the shield has been bent downwards and “jogged” so that the accel pump levers will not hit the shield: If you install a flat shield, the accel pump levers will hit the shield, and will be partially depressed. This will cause an off-idle flat spot and stumble.
In order for the “jogged” shield to clear the base gasket, the gasket “ears” must be trimmed. Shown here is a trimmed base gasket that will allow the bent shield to fit properly.
Shields can be made in many ways. Shown her is the custom shield that I use on my own car. ItÂ’s fabricated from a piece of aluminum sheet stock. Note forward and rear edges bent down to clear accel pump levers.
Important to safety and reliability is a good fuel line. Here, the owner of this carb has sent me his fuel line along with photos of his installation. Based on the photos, I have modified his line to accept a flared, screw-in filter (from Summit), and I have fabricated a flared steel upper line that will screw right into the BG carb inlet fuel line. All threaded steel connections with no rubber hose or clamps used anywhere. See my “How to Build a Fuel Line” article for detailed info on building fuel lines. Drop me an e-mail for a copy of the fuel line article.
Using the ¼” thick insulating gasket under the heat shield requires use of long mounting studs. Note also that the vacuum fitting in the manifold to the rear of the carb has been removed and a flush allen-head pipe plug has been installed to clear the BG rear float bowl and allow installation of the jogged shield.
Complete setup bolted up and ready for test run. Note how heat shield clears all components and is nearly invisible. Steel fuel line keeps things safe and clean looking.
Left side view of completed installation showing dual throttle return springs and shield tucked under carb.
Note that the BG carb does not have a positive throttle stop: It is important that you adjust your cable so that wide open throttle (WOT) is achieved when your gas pedal hits and stops on the floor. If you rely on the carb to stop your gas pedal, you will bend and damage the throttle shaft with your foot pressure. Verify that the throttle returns fully to the idle position when the pedal is released – there should be some slack in the cable at idle. Install a throttle return spring. Verify that the throttle moves freely through its entire range. Adjust as required to achieve proper cable setup.
Prime the carb by pouring a “shot” of fuel down the cast vent tubes on the primary and secondary side. You can do this by pushing a 3/8” fuel line hose onto the vent towers and hooking the hose up to a small funnel.
Pump the gas pedal a few times and verify that fuel shoots out of the accel pump discharge nozzles. Start the engine. Without a choke, you will need to “feather” the gas pedal a little to keep the engine initially running. After 30 seconds or so the engine should run on its own, although at a slow or coarse idle. Check for fuel leaks. Shut down and correct the leaks if required. If no leaks, take the car out and drive it until it is fully warmed up. Once the engine is fully warmed up, perform final adjustments:
Float levels: With the sight glasses, float levels are easy to set up on the BG carbs. For street applications, set the levels to the lower sight line. For performance street and strip applications, go op the middle line.
Idle speed: It is IMPERATIVE that all idle speed adjustments be made by turning the primary AND secondary idle adjustment screws equally. I recommend turning each screw ¼ turn at a time, making sure both screws are turned the same amount in the same direction until desired idle speed is achieved.
Idle mixture: I recommend an initial bench setting of all 4 screws at 1 full turn out from lightly seated. When adjusting idle mixture, all 4 screws MUST be turned the same amount and be kept equal. To test for proper adjustment for your application, play with the primary (forward) idle screw on the passenger side as follows: With the engine warmed up and running, turn this screw ½ turn IN. Note what the engine does (idle drops; idle gets better, etc). Bring the screw back out to the original setting. Now, turn the screw ½ turn OUT. Note what the engine does. If the idle quality improves with one of the settings (for example, if idle quality improves when you turned the screw OUT), adjust all 4 screws ¼ turn in that direction (turn all 4 screws ¼ turn OUT from the 1 turn base setting). Once completed, repeat the entire procedure by turning the one forward screw a little in and a little out to see what direction you need to equally move the 4 screws. As you keep doing this process, keeping all 4 screws equally adjusted, you can narrow down your adjustment to 1/8 turn increments of the screws. You may need to adjust idle speed as you optimize the mixture, keeping both idle speed screws adjusted exactly the same.
Accelerator Pump Arm: To assure proper operation of the accelerator pump, make sure that the pump arm is properly set up against the pump arm screw (spring loaded screw on the lever). With the engine OFF, verify that there is no gap at all between the end of the screw and the pump lever – it should have a little bit of “pre-load.” Verify that the SLIGHTEST movement of the throttle produces an instant discharge of fuel out of the discharge nozzles. Now, open the throttle fully and verify that there is still a little bit of travel left in the pump arm (make sure it’s not bottomed out and jammed solid).
Once this is complete, take the car out and have some fun!
Part numbers used in this article (Summit part numbers):
750 BG Speed Demon Mechanical Secondary Carb: GPT-1402010
Holley Heat Shield (with gaskets): HLY-108-70
In-line fuel filter with threaded connections for 3/8” Fuel line: SUM-G1517
Dual inlet fuel inlet line for BG carbs (for 3/8” fuel line): BGI-140020
Adjustable Throttle cable bracket for C3 (“square hole”) Throttle cable: CSI-630R
Dual throttle return spring set: SUM-G1320
3/8” Aluminum Tube Nut: EAR-581806
3/8” Aluminum Tube Sleeve: EAR-581906
[Modified by lars, 3:01 PM 3/3/2004]
[Modified by lars, 10:00 AM 3/5/2004]
After an interesting series of posts here on the C3 Forum regarding carb sizing, one of our Forum members – “signguy" (Gary – from Florida) – asked me to do a setup on a new Speed Demon 750 for his mildly modified C3. He ordered the carb and all the parts from Summit and had it all drop shipped to me. I took the whole system, modified it, and set it up to run correctly using one of my own cars as the test bed (this 750 mechanical sec carb runs sooooo sweet on my 350…!) Here is the whole sequence to the operation:
Getting a BG Speed Demon carb set up and running right on your engine is all in the prep work: A few bench settings are required, and it’s important to use the right combination of modified parts and accessories to make the installation look good and perform properly. Here are the basic steps (these steps are also detailed in my Tech Paper, “How to Set up a BG Speed Demon.” Drop me an e-mail request for a copy of this paper: V8FastCars@msn.com):
First, set the throttle blade angles. The BG carbs (and Holley carbs, too) need to meter equal air through both primary and secondary sides of the carb at idle. This is never set correctly on an out-of-the-box carb. To do this, flip the carb upside-down and adjust the primary and secondary idle speed screws so that .020” of the transition slot is exposed on all 4 throttle blades. Use a feeler gauge to check. (After you’ve done a few of these, you can do it by eyeballing it: The transition slots are .020” wide, so you can adjust the throttles so that the exposed part of the slot appears as a square hole under the throttle blade.)
Throttle blades cracked open to show the vertical transition slots. These slots start metering fuel as you come off idle and as you go into the main discharge circuit. If too much of the slots are exposed, idle mixtures will be incorrect. .020” of the slots should be exposed below the edge of the throttle blades.
“Out-of-the-box” setting of the throttle blades shows secondary throttle closed completely – there is no exposure of the transition slot on the secondary side. Primary side had massive slot exposure to compensate for lack of adjustment on secondary side.
Correctly set throttle blade angle. .020” of the slots are exposed below the blades. Both primary and secondary throttles should be set exactly like this.
The BG carbs, and most Holleys, have only a single 3/8” vacuum port for connection of the PCV. If you’re running power brakes, you can install a “T” system like this to run PCV and brakes. I have made the “T” section short enough that it is hidden under the secondary bowl. This makes a very clean installation. Note twin vacuum nipples coming out of the side of the throttle plate: The forward nipple (right) is ported vacuum for distributor vacuum advance. The rear nipple (left) is direct manifold vacuum for vacuum accessories. You can also use direct manifold vacuum for distributor advance depending on the tuning needs of your engine – see my tuning articles discussing these concepts.
BG and Holley carbs need a reflective heat shield installed under the carb: The accelerator pump wells are close enough to the hot manifold that the fuel in the pump wells will boil after hot engine shutdown. As the fuel boils and vaporizes, it pushes fuel out the accel discharge nozzles, flooding the engine after shutdown. Holley builds a shield, but it does not fit correctly. Seen here is a modified Holley shield: I have trimmed about an inch off the forward edge so it will clear the thermostat housing. The rear edge has been trimmed forward. The right side of the shield has been cut inwards to prevent the throttle shafts from binding on the shield. The right corners have been trimmed at a 45-degree angle to clear the carb inlet line. Finally, the shield has been bent downwards and “jogged” so that the accel pump levers will not hit the shield: If you install a flat shield, the accel pump levers will hit the shield, and will be partially depressed. This will cause an off-idle flat spot and stumble.
In order for the “jogged” shield to clear the base gasket, the gasket “ears” must be trimmed. Shown here is a trimmed base gasket that will allow the bent shield to fit properly.
Shields can be made in many ways. Shown her is the custom shield that I use on my own car. ItÂ’s fabricated from a piece of aluminum sheet stock. Note forward and rear edges bent down to clear accel pump levers.
Important to safety and reliability is a good fuel line. Here, the owner of this carb has sent me his fuel line along with photos of his installation. Based on the photos, I have modified his line to accept a flared, screw-in filter (from Summit), and I have fabricated a flared steel upper line that will screw right into the BG carb inlet fuel line. All threaded steel connections with no rubber hose or clamps used anywhere. See my “How to Build a Fuel Line” article for detailed info on building fuel lines. Drop me an e-mail for a copy of the fuel line article.
Using the ¼” thick insulating gasket under the heat shield requires use of long mounting studs. Note also that the vacuum fitting in the manifold to the rear of the carb has been removed and a flush allen-head pipe plug has been installed to clear the BG rear float bowl and allow installation of the jogged shield.
Complete setup bolted up and ready for test run. Note how heat shield clears all components and is nearly invisible. Steel fuel line keeps things safe and clean looking.
Left side view of completed installation showing dual throttle return springs and shield tucked under carb.
Note that the BG carb does not have a positive throttle stop: It is important that you adjust your cable so that wide open throttle (WOT) is achieved when your gas pedal hits and stops on the floor. If you rely on the carb to stop your gas pedal, you will bend and damage the throttle shaft with your foot pressure. Verify that the throttle returns fully to the idle position when the pedal is released – there should be some slack in the cable at idle. Install a throttle return spring. Verify that the throttle moves freely through its entire range. Adjust as required to achieve proper cable setup.
Prime the carb by pouring a “shot” of fuel down the cast vent tubes on the primary and secondary side. You can do this by pushing a 3/8” fuel line hose onto the vent towers and hooking the hose up to a small funnel.
Pump the gas pedal a few times and verify that fuel shoots out of the accel pump discharge nozzles. Start the engine. Without a choke, you will need to “feather” the gas pedal a little to keep the engine initially running. After 30 seconds or so the engine should run on its own, although at a slow or coarse idle. Check for fuel leaks. Shut down and correct the leaks if required. If no leaks, take the car out and drive it until it is fully warmed up. Once the engine is fully warmed up, perform final adjustments:
Float levels: With the sight glasses, float levels are easy to set up on the BG carbs. For street applications, set the levels to the lower sight line. For performance street and strip applications, go op the middle line.
Idle speed: It is IMPERATIVE that all idle speed adjustments be made by turning the primary AND secondary idle adjustment screws equally. I recommend turning each screw ¼ turn at a time, making sure both screws are turned the same amount in the same direction until desired idle speed is achieved.
Idle mixture: I recommend an initial bench setting of all 4 screws at 1 full turn out from lightly seated. When adjusting idle mixture, all 4 screws MUST be turned the same amount and be kept equal. To test for proper adjustment for your application, play with the primary (forward) idle screw on the passenger side as follows: With the engine warmed up and running, turn this screw ½ turn IN. Note what the engine does (idle drops; idle gets better, etc). Bring the screw back out to the original setting. Now, turn the screw ½ turn OUT. Note what the engine does. If the idle quality improves with one of the settings (for example, if idle quality improves when you turned the screw OUT), adjust all 4 screws ¼ turn in that direction (turn all 4 screws ¼ turn OUT from the 1 turn base setting). Once completed, repeat the entire procedure by turning the one forward screw a little in and a little out to see what direction you need to equally move the 4 screws. As you keep doing this process, keeping all 4 screws equally adjusted, you can narrow down your adjustment to 1/8 turn increments of the screws. You may need to adjust idle speed as you optimize the mixture, keeping both idle speed screws adjusted exactly the same.
Accelerator Pump Arm: To assure proper operation of the accelerator pump, make sure that the pump arm is properly set up against the pump arm screw (spring loaded screw on the lever). With the engine OFF, verify that there is no gap at all between the end of the screw and the pump lever – it should have a little bit of “pre-load.” Verify that the SLIGHTEST movement of the throttle produces an instant discharge of fuel out of the discharge nozzles. Now, open the throttle fully and verify that there is still a little bit of travel left in the pump arm (make sure it’s not bottomed out and jammed solid).
Once this is complete, take the car out and have some fun!
Part numbers used in this article (Summit part numbers):
750 BG Speed Demon Mechanical Secondary Carb: GPT-1402010
Holley Heat Shield (with gaskets): HLY-108-70
In-line fuel filter with threaded connections for 3/8” Fuel line: SUM-G1517
Dual inlet fuel inlet line for BG carbs (for 3/8” fuel line): BGI-140020
Adjustable Throttle cable bracket for C3 (“square hole”) Throttle cable: CSI-630R
Dual throttle return spring set: SUM-G1320
3/8” Aluminum Tube Nut: EAR-581806
3/8” Aluminum Tube Sleeve: EAR-581906
[Modified by lars, 3:01 PM 3/3/2004]
[Modified by lars, 10:00 AM 3/5/2004]
03-03-2004, 04:57 PM
#3
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Re: How to Set up & Install a 750 Speed Demon on a 350 (1bad69)
Mike -
Did the part number list at the end of that post give you the info you need...?
Did the part number list at the end of that post give you the info you need...?
03-03-2004, 05:04 PM
#4
Tech Contributor
Re: How to Set up & Install a 750 Speed Demon on a 350 (lars)
Lars,
I have a new 670 Holley St Avenger to install soon, do these tips apply to that carb too? Have you used any of these carbs,if so any other tips I should consider?
Thanks,
Gary
I have a new 670 Holley St Avenger to install soon, do these tips apply to that carb too? Have you used any of these carbs,if so any other tips I should consider?
Thanks,
Gary
03-03-2004, 05:15 PM
#5
Re: How to Set up & Install a 750 Speed Demon on a 350 (lars)
Mike -
Did the part number list at the end of that post give you the info you need...?
Did the part number list at the end of that post give you the info you need...?
03-03-2004, 05:23 PM
#6
Burning Brakes
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Re: How to Set up & Install a 750 Speed Demon on a 350 (lars)
Hi Lars, Thank you so much for the great detailed info on the carb setup. I now can see exactly what you are talking about on the transfer slots. My question on my setup is I dont have a heat shield , just a gasket that is about 1\8" thick, should I consider getting the Holley heat shield for my motor? It seems to run fine even after hard driving and shutting it off. I am sure that Signguy is going to be one happy guy with the new carb on his car!!!
03-03-2004, 05:25 PM
#8
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Re: How to Set up & Install a 750 Speed Demon on a 350 (gtr1999)
gtr -
The Holley Street Avenger does not have 4-corner idle mixture screws, but like all Holleys, it has an idle fuel transfer passage from the primary to the secondary side allowing it to discharge idle fuel on the secondary side. For this reason, you want to set up your secondary throttles with the same airgap around them as the primafry throttles. Note that the Holley carbs have the secondary transition slots set higher in the throttle bores than on the primary side, so you cannot use the .020" measurement for setting the secondary side: you have to set the primary side to .020", hold the carb up to a light so you can see the "light gap" around the throttle blades, and then adjust the secondary throttles to match the light gap of the primary side.
Also, the Holley Street Avenger has in-carb filters, so there is no need to run an in-line filter as shown in this article.
Run the softest spring you can on the secondary side of that vacuum sec carb - it has a hard time getting the secondaries wide open...
The Holley Street Avenger does not have 4-corner idle mixture screws, but like all Holleys, it has an idle fuel transfer passage from the primary to the secondary side allowing it to discharge idle fuel on the secondary side. For this reason, you want to set up your secondary throttles with the same airgap around them as the primafry throttles. Note that the Holley carbs have the secondary transition slots set higher in the throttle bores than on the primary side, so you cannot use the .020" measurement for setting the secondary side: you have to set the primary side to .020", hold the carb up to a light so you can see the "light gap" around the throttle blades, and then adjust the secondary throttles to match the light gap of the primary side.
Also, the Holley Street Avenger has in-carb filters, so there is no need to run an in-line filter as shown in this article.
Run the softest spring you can on the secondary side of that vacuum sec carb - it has a hard time getting the secondaries wide open...
03-03-2004, 05:56 PM
#9
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Re: How to Set up & Install a 750 Speed Demon on a 350 (Eric R)
Eric -
If your mixtures are set up correctly, the BG will achieve the same gas mileage as any other good carb. I am getting identical mileage at cruise with my 750 BG as I was getting with my Q-Jet. The only problem with the BG is that it's so much fun to push the pedal to the floor.... :yesnod:
If your mixtures are set up correctly, the BG will achieve the same gas mileage as any other good carb. I am getting identical mileage at cruise with my 750 BG as I was getting with my Q-Jet. The only problem with the BG is that it's so much fun to push the pedal to the floor.... :yesnod:
03-03-2004, 06:00 PM
#10
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Re: How to Set up & Install a 750 Speed Demon on a 350 (467-Ratman)
467 -
If you're not having a fuel boiling problem or a hot-start flooding problem you can skip the shield. In many geographical areas there is alcohol added to the gasoline to reduce CO emissions. Alcohol has a lower boiling point (higher vapor pressure) than gasoline, so the use of these fuels is causing a problem for many people. The shield reduces the tendency for the fuel to boil if you have high vapor pressure fuel in your area.
If you're not having a fuel boiling problem or a hot-start flooding problem you can skip the shield. In many geographical areas there is alcohol added to the gasoline to reduce CO emissions. Alcohol has a lower boiling point (higher vapor pressure) than gasoline, so the use of these fuels is causing a problem for many people. The shield reduces the tendency for the fuel to boil if you have high vapor pressure fuel in your area.
03-03-2004, 06:26 PM
#11
Le Mans Master
Re: How to Set up & Install a 750 Speed Demon on a 350 (lars)
Lars can you achieve the same (relative) gains with an Edel Perf 750 mech carb? See you in June, mine is basically new out of the box still anything I should buy in the way of parts for your arrival?
03-03-2004, 06:40 PM
#12
Race Director
Re: How to Set up & Install a 750 Speed Demon on a 350 (gdh)
Lars, can the same idle mixture proceedure be used for a Holley 750 DP. I have had nothing but problems trying to adjust them on mine. It seem I can move 3 of the screws (drivers side forward and the two on the passenger side ) in a out a fair bit and hardly anything happens but as soon as I move the drivers side back in or out only a little it has a real effect and will stall if I go too far.
Do you know the reason this is happening ? I gave up :D
Thanks for taking the time to write the tech paper
[Modified by MotorHead, 5:41 PM 3/3/2004]
Do you know the reason this is happening ? I gave up :D
Thanks for taking the time to write the tech paper
[Modified by MotorHead, 5:41 PM 3/3/2004]
03-03-2004, 06:59 PM
#13
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Re: How to Set up & Install a 750 Speed Demon on a 350 (MotorHead)
Thanks Lars :cool: . I have the exact same carb waiting to be installed on my 383. I'd already have it up running but I decided to cleanup and paint the engine bay while the motor was out. I also sent you an e-mail for both the tech papers that you mentioned :cheers:
03-03-2004, 07:25 PM
#14
Safety Car
Re: How to Set up & Install a 750 Speed Demon on a 350 (Ryan77)
i just got home and checked my email, where i found a note from Lars telling me of this post...(usually the 2nd place i go on the computer)
so natrualy i came directly here!
all i can say is WOW... :party:
i am SO excited... :D
Lars...it looks AWESOME !!! THANK YOU, THANK YOU, THANK YOU... :)
you can bet that i will be watching the mail and once it arrives, it wont sit there long! i will be boltin her on!
and i will darn sure be back here reporting the results... :yesnod:
once again...thank you so much Lars...you ARE the man...
your knowledge and abilities are only matched by your kindness. generosity and willingness to share your time and what you know with others that love our crazy "hobby"...
so natrualy i came directly here!
all i can say is WOW... :party:
i am SO excited... :D
Lars...it looks AWESOME !!! THANK YOU, THANK YOU, THANK YOU... :)
you can bet that i will be watching the mail and once it arrives, it wont sit there long! i will be boltin her on!
and i will darn sure be back here reporting the results... :yesnod:
once again...thank you so much Lars...you ARE the man...
your knowledge and abilities are only matched by your kindness. generosity and willingness to share your time and what you know with others that love our crazy "hobby"...
03-03-2004, 07:28 PM
#15
Le Mans Master
Re: How to Set up & Install a 750 Speed Demon on a 350 (Ryan77)
Great article Lars & perfect timing. I would like to install EFI onto my car, but still have a fair amount of $ to spend to get it running, so I'm looking at installing a carb for now (maybe keep it if I can get it running right ;) ) & the Demon is the carb I've been eyeballing :D
Thanks !!! :cheers:
Thanks !!! :cheers:
03-03-2004, 08:17 PM
#16
Drifting
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Re: How to Set up & Install a 750 Speed Demon on a 350 (lars)
Just a note for clarification....
For those of you who have read the thread dissing C2 drivers.....this typical fantastic information was developed by Lars on HIS C2.....a'64 vert aptly named "Goldmember"!!
Ya see.....for all the unbelieveable information and building jobs Lars has supplied ALL Forum members, particularly C3ers, in the end, he is a C2 driver.
Weird, huh??!
*******************
Jeff
:cheers: :seeya to all
[Modified by Blkblt, 6:21 PM 3/3/2004]
For those of you who have read the thread dissing C2 drivers.....this typical fantastic information was developed by Lars on HIS C2.....a'64 vert aptly named "Goldmember"!!
Ya see.....for all the unbelieveable information and building jobs Lars has supplied ALL Forum members, particularly C3ers, in the end, he is a C2 driver.
Weird, huh??!
*******************
Jeff
:cheers: :seeya to all
[Modified by Blkblt, 6:21 PM 3/3/2004]
03-03-2004, 09:07 PM
#17
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Re: How to Set up & Install a 750 Speed Demon on a 350 (gdh)
gdh -
It depends on which "Performer" carb you have. If you have the AFB re-pop, I can't do much for tuning. If you have the Q-Jet re-pop, we can make some nice improvements. Tuning methods on the Q-Jet are significantly different from the Holley/BG methods, so the items discussed in this post do not apply to the Q-Jet carbs. Look forward to the Toronto Tuning Tour this summer!
It depends on which "Performer" carb you have. If you have the AFB re-pop, I can't do much for tuning. If you have the Q-Jet re-pop, we can make some nice improvements. Tuning methods on the Q-Jet are significantly different from the Holley/BG methods, so the items discussed in this post do not apply to the Q-Jet carbs. Look forward to the Toronto Tuning Tour this summer!
03-03-2004, 09:13 PM
#18
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Re: How to Set up & Install a 750 Speed Demon on a 350 (MotorHead)
Motorhead -
The Holley 750DP uses the identical setup procedure as described for this BG 750. However, if you have unresponsive screws, tear the carb apart and blow down each one of the idle feed passages with compressed air. Verify the flow through all the passages by squirting WD40 through them (using the stupid little red plastic tube that you get with the bottle). Then bolt it together and set it up as described. If you can't get it, send it out to me and I'll do a Forum tech post on it...
The Holley 750DP uses the identical setup procedure as described for this BG 750. However, if you have unresponsive screws, tear the carb apart and blow down each one of the idle feed passages with compressed air. Verify the flow through all the passages by squirting WD40 through them (using the stupid little red plastic tube that you get with the bottle). Then bolt it together and set it up as described. If you can't get it, send it out to me and I'll do a Forum tech post on it...
03-03-2004, 09:20 PM
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Re: How to Set up & Install a 750 Speed Demon on a 350 (lars)
Heres some pics of my 650 bg, i was told the 750 was WAY TOO BIG for a 350 even if modified. Hmmm odd.
:cool:
:cool:
03-03-2004, 09:21 PM
#20
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Re: How to Set up & Install a 750 Speed Demon on a 350 (Blkblt)
Blkblt -
Yes, ol' Blkblt (Jeff) is right - I do test all C3 parts on my '64 Roadster appropriately named "Goldmember." All the C3 Q-Jets, Holleys and BGs have been run on my 350 '64. I have a complete dual-system testing setup that allows me to bolt on either spread-bore or square-bore carbs right onto the '64 Forum Test Mule. We also frequently have the Colorado Corvette Crazies guys (CCC) take the car out with Forum members' parts on it and run the holy ^%$# out of it. I figure if these CCC morons can't break the parts, they should be good enough to send back to you guys...!
I do appreciate Jeff not mentioning that I'm actually a C4 driver....
Yes, ol' Blkblt (Jeff) is right - I do test all C3 parts on my '64 Roadster appropriately named "Goldmember." All the C3 Q-Jets, Holleys and BGs have been run on my 350 '64. I have a complete dual-system testing setup that allows me to bolt on either spread-bore or square-bore carbs right onto the '64 Forum Test Mule. We also frequently have the Colorado Corvette Crazies guys (CCC) take the car out with Forum members' parts on it and run the holy ^%$# out of it. I figure if these CCC morons can't break the parts, they should be good enough to send back to you guys...!
I do appreciate Jeff not mentioning that I'm actually a C4 driver....