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Post Info TOPIC: BBC tuning



- Jason -
Marysville, WA


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BBC tuning
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SleepernSeattle wrote:

Sorry that should've read 1722. You know I do need to check my choke blade since it was added later on. That seems like a very likely cause. What do you mean by a secondary lockout? Also I just put a tee in where fuel psi gauge is, so I kept one gauge by the carb then ran a hose up to a second gauge that I mounted under the cowl and can be easily seen from the driver's seat. This way I can confirm I'm not losing(or gaining lots of) psi while I'm experiencing this issue.


 Some carbs will not allow the secondary butterflies to open until the choke is completely warm and the choke flap is straight up and down.

BTW an Edelbrock 750 with electric choke has part #1411 http://www.summitracing.com/parts/edl-1411/overview/



-- Edited by JBSS396 on Tuesday 9th of December 2014 08:02:01 PM

__________________

69 Chevelle SS 
454 10.4:1, Engle HFT cam 244/260 at .050", .570 lift, 850 Mighty Demon Carb, TH 350, 10" TCI 3500, 12 Bolt 373's, 28x10.5 slicks 

Best Time at Pacific 6/20/2014, 11.96 @ 110 mph.

79 Malibu: 350 with Vortec heads, Performer Intake, Q-jet, TH350, 3.31 gears

Tow rig: 82 Chev C20 Scottsdale 454




Rick
Mountlake Terrace, WA


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sleeper, give me a call please. shooting you a pm with cell. im in terrace and can pop by and put another set of eyes on it.


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67 Chevelle 



- GearHead -

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text sent

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71 Malibu Convertible 408ci LS3 BBC

Edlbrk RPM Heads/intake/Holley Ultra HP 750

Custom Bullet SFT Cam

Forged pistons/cast crank/ARP rod bolts.

trans&rear: 700r4/3k stall, 3.73 posi 12 bolt 

Best 1/4 mi: 12.91 @ 104.69, 1.83 60', DA corrected 12.7 @ 106.45

dyno & 1/4mi videos: https://www.youtube.com/channel/UCbiO_bxyda5QWMDTQAuOEtg




- Doc Smokum -
- BB Emporium -


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I have my ol'faithful 800 DP Holley we can throw on it to see how you like a holley if you want to go that direction as well or at least compare. It's been ran on several memebers cars here and sitting on a 496 right now. Takes 10 minutes to pull it off.

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Welfare Nova 10.13 @ 131 N/A, can't wait for a full squeeze pass and some traction, 9's coming. 



- GearHead -

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Much appreciated! Let's see if we can figure out the ebrock.. if Rick and I are stumped we'll have to start considering other directions to go carb-wise.. Where are you located?



-- Edited by SleepernSeattle on Thursday 11th of December 2014 12:49:03 PM

__________________

71 Malibu Convertible 408ci LS3 BBC

Edlbrk RPM Heads/intake/Holley Ultra HP 750

Custom Bullet SFT Cam

Forged pistons/cast crank/ARP rod bolts.

trans&rear: 700r4/3k stall, 3.73 posi 12 bolt 

Best 1/4 mi: 12.91 @ 104.69, 1.83 60', DA corrected 12.7 @ 106.45

dyno & 1/4mi videos: https://www.youtube.com/channel/UCbiO_bxyda5QWMDTQAuOEtg



- GearHead -

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Ok I got a chance to warm her up and take her out for a run. It was in the eye of our wind/rain storm so the roads were wet making it difficult to judge "power" but I was able to nail a few items down:
1: Fuel pressure is stable at 6.5-7psi throughout the rpm range. Is this to high? I have the ebrock fuel pump 1722 that states it does not need a psi regulator but maybe I do need a regulator?
2. The car does appear to be shifting at 3500, so I don't think the motor is falling off. This maybe a simple fix by adjusting the TC.
3. At idle the rpms are surging back and forth between about 600-900, vac back and forth between about 9" and 12".
4. Timing is currently sitting around 23-base (18 advance bushing- total of 41) No vac advance hooked up..
5. The electric choke is working and opening once warmed up although I think it could use some minor tweaking as I have to hold my foot on the gas for a couple minutes for it to run while it warms up.
Now a couple questions.
1. In the carb, there are two sets of blades in the secondaries. The lower ones are the throttle blades and are opening, just before WOT, but there is a second set of blades/flappers above the throttle blades that are not opening fully, they seem stationary at a partially open position. What are these and are they supposed to be opening?

2. The surging at idle is new today. It wasn't doing that before, the only thing I changed was I gave it a small bump in timing from 22 to about 23-24ish.. could this cause surging?

So in summary I'm leaning towards there are a few things at play here: the trans throttle cable needs adjusting, the carb still needs some tuning and there must be some other factors at play here I'm missing, like a vacuum leak or something. But I've tried the propane method and wasn't able to detect any leaks..

__________________

71 Malibu Convertible 408ci LS3 BBC

Edlbrk RPM Heads/intake/Holley Ultra HP 750

Custom Bullet SFT Cam

Forged pistons/cast crank/ARP rod bolts.

trans&rear: 700r4/3k stall, 3.73 posi 12 bolt 

Best 1/4 mi: 12.91 @ 104.69, 1.83 60', DA corrected 12.7 @ 106.45

dyno & 1/4mi videos: https://www.youtube.com/channel/UCbiO_bxyda5QWMDTQAuOEtg




- Mike -
Puyallup, WA


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Posts: 2644
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Sounds to me like you need more air, more fuel and adjust the trans modulator.

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'67 Chevelle -- 383ci, Jerico DR4 4 speed -- 3.19 1st gearset, Gear Vendors Overdrive/Underdrive, Strange S60 w/3.54 gears

'70 Camaro -- In the works TT 6.0L, 4L80E, ??? rear end 



- GearHead -

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Ok how should I accomplish these things? For the trans cable do I pull it out farther or let it back in some?

__________________

71 Malibu Convertible 408ci LS3 BBC

Edlbrk RPM Heads/intake/Holley Ultra HP 750

Custom Bullet SFT Cam

Forged pistons/cast crank/ARP rod bolts.

trans&rear: 700r4/3k stall, 3.73 posi 12 bolt 

Best 1/4 mi: 12.91 @ 104.69, 1.83 60', DA corrected 12.7 @ 106.45

dyno & 1/4mi videos: https://www.youtube.com/channel/UCbiO_bxyda5QWMDTQAuOEtg




- Doc Smokum -
- BB Emporium -


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Modulator valve on the trans should be adjustable, pull the vacuum hose off and use a small flat bladed screw driver and screw it in to raise the shift points.


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Welfare Nova 10.13 @ 131 N/A, can't wait for a full squeeze pass and some traction, 9's coming. 




- Doc Smokum -
- BB Emporium -


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The cable from the trans is a detent cable for kick down and will also affect shifting. I gorget the process for adjusting that. I believe it's loosen the lock on the cable, open to WOT and lock it back.

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Welfare Nova 10.13 @ 131 N/A, can't wait for a full squeeze pass and some traction, 9's coming. 




- Jason -
Marysville, WA


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Since you have a 700R4 trans, the throttle valve cable (located below the accelerator cable) will need to be adjusted if your full throttle up shifts are only at 3500 rpms.

Before you get started make sure you have the correct TV cable bracket for your Edelbrock carb.

Throttle to TV adapter.JPG

Your setup should look something like this.

Edelbrock carb-TV set up example.jpg

To make this adjustment follow the instructions on this picture I found (don't worry about it saying its for a diesel, its the same).

700R4 TV-Cable adjustment.jpg

After you have completed all the steps above take the car for a test drive.

1) Notice how the trans shifts at normal lite throttle, what speed and rpm.

2) Then find an opportunity to go from a stop or very slow and use heavy throttle or full throttle if you can see what rpm the trans shifts. A good shift point is between 5000-5500 rpms.

3) If the trans shifts too early still, press and hold the adjustment lock tab down while you move the slider back toward the firewall a click or 2 until the desired shift rpm is reached. Test drive after each adjustment.

TV shift higher.JPG

4) If the engine revs very high at full throttle without shifting or you have to let off for it to shift, adjust the slider out toward the carb a little at a time. Test drive after each adjustment.

TV shift lower.jpg

If you have a Lokar brand cable then there is a whole different procedure to adjust it. Let me know if that is the case.

Lokar 700R4 TV cable.JPG

 

 



-- Edited by JBSS396 on Saturday 13th of December 2014 04:44:32 AM

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__________________

69 Chevelle SS 
454 10.4:1, Engle HFT cam 244/260 at .050", .570 lift, 850 Mighty Demon Carb, TH 350, 10" TCI 3500, 12 Bolt 373's, 28x10.5 slicks 

Best Time at Pacific 6/20/2014, 11.96 @ 110 mph.

79 Malibu: 350 with Vortec heads, Performer Intake, Q-jet, TH350, 3.31 gears

Tow rig: 82 Chev C20 Scottsdale 454



- GearHead -

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I believe I have the Lokar style, but its not that brand.. I've attached a pic of the cable installed and the package it came in.  I guess what I'm wondering is do I pull the cable out more or let it back in more or is it more involved then that..



Attachments
__________________

71 Malibu Convertible 408ci LS3 BBC

Edlbrk RPM Heads/intake/Holley Ultra HP 750

Custom Bullet SFT Cam

Forged pistons/cast crank/ARP rod bolts.

trans&rear: 700r4/3k stall, 3.73 posi 12 bolt 

Best 1/4 mi: 12.91 @ 104.69, 1.83 60', DA corrected 12.7 @ 106.45

dyno & 1/4mi videos: https://www.youtube.com/channel/UCbiO_bxyda5QWMDTQAuOEtg



- GearHead -

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I'm not sure why my pics end up so tiny when I attach them. I take them on my phone, send them to my email, open my email on my laptop, save the pic to my laptop, and then upload it. When I open the file from my hard drive they are really big and a lot more clear.. So not sure what happens when I attach them. Anyone know how I can fix this?

__________________

71 Malibu Convertible 408ci LS3 BBC

Edlbrk RPM Heads/intake/Holley Ultra HP 750

Custom Bullet SFT Cam

Forged pistons/cast crank/ARP rod bolts.

trans&rear: 700r4/3k stall, 3.73 posi 12 bolt 

Best 1/4 mi: 12.91 @ 104.69, 1.83 60', DA corrected 12.7 @ 106.45

dyno & 1/4mi videos: https://www.youtube.com/channel/UCbiO_bxyda5QWMDTQAuOEtg




- Jason -
Marysville, WA


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Posts: 1461
Date:
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SleepernSeattle wrote:

I believe I have the Lokar style, but its not that brand.. I've attached a pic of the cable installed and the package it came in.  I guess what I'm wondering is do I pull the cable out more or let it back in more or is it more involved then that..


 Here are the instructions explaining how to adjust the lokar style cable, it is very similar to the stock instructions in how to fine adjust the cable, only the adjuster is threaded instead of using a spring loaded lever and button to release. See step 11 and figure 6

http://static.summitracing.com/global/images/instructions/LOK-INS0003-GMhitech-KickdownKit.pdf

To increase up-shift rpms move the cable, shown in green, to the right by moving the lock nuts, in orange, to the left.

Lokar 700R4 cables.JPG

-- Edited by JBSS396 on Saturday 13th of December 2014 07:20:29 PM



-- Edited by JBSS396 on Saturday 13th of December 2014 08:46:45 PM

Attachments
__________________

69 Chevelle SS 
454 10.4:1, Engle HFT cam 244/260 at .050", .570 lift, 850 Mighty Demon Carb, TH 350, 10" TCI 3500, 12 Bolt 373's, 28x10.5 slicks 

Best Time at Pacific 6/20/2014, 11.96 @ 110 mph.

79 Malibu: 350 with Vortec heads, Performer Intake, Q-jet, TH350, 3.31 gears

Tow rig: 82 Chev C20 Scottsdale 454




- Jason -
Marysville, WA


Status: Offline
Posts: 1461
Date:
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SleepernSeattle wrote:

I'm not sure why my pics end up so tiny when I attach them. I take them on my phone, send them to my email, open my email on my laptop, save the pic to my laptop, and then upload it. When I open the file from my hard drive they are really big and a lot more clear.. So not sure what happens when I attach them. Anyone know how I can fix this?


 Try this: After you attach each pic it will give you an option to insert it, try to insert the pics then click preview post so you can see what it will look like before finally posting.

 



__________________

69 Chevelle SS 
454 10.4:1, Engle HFT cam 244/260 at .050", .570 lift, 850 Mighty Demon Carb, TH 350, 10" TCI 3500, 12 Bolt 373's, 28x10.5 slicks 

Best Time at Pacific 6/20/2014, 11.96 @ 110 mph.

79 Malibu: 350 with Vortec heads, Performer Intake, Q-jet, TH350, 3.31 gears

Tow rig: 82 Chev C20 Scottsdale 454



- GearHead -

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Posts: 242
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Ok just so I understand, move the cable housing back towards the trans? Not the cable end stop?

__________________

71 Malibu Convertible 408ci LS3 BBC

Edlbrk RPM Heads/intake/Holley Ultra HP 750

Custom Bullet SFT Cam

Forged pistons/cast crank/ARP rod bolts.

trans&rear: 700r4/3k stall, 3.73 posi 12 bolt 

Best 1/4 mi: 12.91 @ 104.69, 1.83 60', DA corrected 12.7 @ 106.45

dyno & 1/4mi videos: https://www.youtube.com/channel/UCbiO_bxyda5QWMDTQAuOEtg



- GearHead -

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Posts: 242
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I called the trans builder and described my issues to him, he said to make sure my detent cable would not pull out any further once at WOT. So I went down the garage, had my 10 months preggers wife push down on the gas pedal, I confirmed the carb linkage was all the way engaged, and low and behold I was able to pull out another inch of cable. This surprises me bc that's how I set it, but maybe it slipped or I was just being an idiot when I set it the first time. Regardless I knocked the timing back to 16, gave the idle screw a half turn to bring the idle back up to 800rpm and took her out for a drive, holy smokes. The car pulls hards all the way into the 5k rpms range, breaks the tires loose shifting into 2nd and going 70mph in no time.. I think there's still some tuning left to do in the carb but I'd say it's 90% there! Thanks for all of your help guys. Were heading to this hospital tonight for inducing so fingers crossed the next time I'm posting I have healthy baby boy!

__________________

71 Malibu Convertible 408ci LS3 BBC

Edlbrk RPM Heads/intake/Holley Ultra HP 750

Custom Bullet SFT Cam

Forged pistons/cast crank/ARP rod bolts.

trans&rear: 700r4/3k stall, 3.73 posi 12 bolt 

Best 1/4 mi: 12.91 @ 104.69, 1.83 60', DA corrected 12.7 @ 106.45

dyno & 1/4mi videos: https://www.youtube.com/channel/UCbiO_bxyda5QWMDTQAuOEtg



- Beemer Brett - Redmond, WA

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Bring him home in the Chevelle doing burnouts!

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1966 Chevelle, 1972 K20, 1967 GTO, 1955 210 Coupe, 1969 Chevelle




- wondah whooooaman-
Colorado Springs


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SleepernSeattle wrote:

I called the trans builder and described my issues to him, he said to make sure my detent cable would not pull out any further once at WOT. So I went down the garage, had my 10 months preggers wife push down on the gas pedal, I confirmed the carb linkage was all the way engaged, and low and behold I was able to pull out another inch of cable. This surprises me bc that's how I set it, but maybe it slipped or I was just being an idiot when I set it the first time. Regardless I knocked the timing back to 16, gave the idle screw a half turn to bring the idle back up to 800rpm and took her out for a drive, holy smokes. The car pulls hards all the way into the 5k rpms range, breaks the tires loose shifting into 2nd and going 70mph in no time.. I think there's still some tuning left to do in the carb but I'd say it's 90% there! Thanks for all of your help guys. Were heading to this hospital tonight for inducing so fingers crossed the next time I'm posting I have healthy baby boy!


 Hope everything turns out well at the hospital!!



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Mark
69 Chevelle SS
"Carpe Jugulum"
"Only those who have never learned self-restraint fear reasonable discipline" T.R. Fehrenbach

http://www.chevelles.com/showroom/data/500/showpic1.jpg
http://www.chevelles.com/showroom/da...ium/motor2.JPG
http://www.chevelles.com/showroom/data/500/breakout.JPG



- Jason -
Marysville, WA


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Glad you're on the right track with the trans TV cable tuning.

Good luck and congrats on the new baby.

__________________

69 Chevelle SS 
454 10.4:1, Engle HFT cam 244/260 at .050", .570 lift, 850 Mighty Demon Carb, TH 350, 10" TCI 3500, 12 Bolt 373's, 28x10.5 slicks 

Best Time at Pacific 6/20/2014, 11.96 @ 110 mph.

79 Malibu: 350 with Vortec heads, Performer Intake, Q-jet, TH350, 3.31 gears

Tow rig: 82 Chev C20 Scottsdale 454

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