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Topic Review (Newest First)
07-21-2008 02:33 PM
camaro freak
BG Tech...

Ok, if it don't sell I will call you folks to see what I should do. Thank you to all!!!
07-21-2008 09:21 AM
Tech @ BG
Quote:
Originally Posted by camaro freak
After driving the car for about an hour I pulled a plug to read it. It looked much better than the other plugs. After studying the plug link and making comparisons to the pictures I would say that the Holley is only slightly rich and I need to bring timing down to around 14 deg advance from 16 degrees, but really the plug is very close to looking like the picture of best. Now here is a question for the BG tech! If the BG Mighty Demon carb I have listed on eBay don't sell can I replace the metering blocks with a set that is leaner or is changing the jets all that can be done?
The Mighty Demon has an adjustable idle feed restrictor as well as adjustable idle air bleeds so if the idle circuit needs to be leaned out it can be done by a combination of both.
07-21-2008 09:20 AM
Tech @ BG
Quote:
Originally Posted by camaro freak
Awesome plug info link... Ok folks we got it! I tested the distributor and wires and all was good! I built a spark plug tester using a 24 volt spark ingintor from a furnace and the transformer so I could test each spark plug. As I went from plug to plug I noticed that each spark looked weak. The sparks were orange in color and not like the nice blue spark that came from the wire when I tested it. We got to plug 8 and guess what? NO spark!!! None at all!!! So we made a trip to Advance and what the heck lets grab those 5 year warranty E3 plugs at $7 each and see what happens! Well, after laying a patch 25 feet long and burying the speedo I would say we found our problem! I plan to let the motor cool some and then read a few plugs and adjust if necessary. I do however plan to stay with a Holley. I want a 750 double pumper HP carb, I may consider an 850 double pumper after reading the test results from the 383 build that Chevy High Perf magazine got! If someone has a good new or like new Holley like I want, drop me a note in the next few hours, well by 9 pm est and maybe we can work out a deal. The BG carb I have is like new, honestly, we have only put about 100 miles on it. We changed the PV and put reusable blue gaskets on it and that is all we did outside of adjusting it. After 9 pm est it will be on eBay! Thanks to all for the help!!! I hope this thread is helpful to someone else!
I am glad you posted what you found as the carburetor always seems to be the first to get blamed for everything. Good to see you found the issue with the ignition and got it straightened out.
07-21-2008 09:11 AM
camaro freak
more...

After driving the car for about an hour I pulled a plug to read it. It looked much better than the other plugs. After studying the plug link and making comparisons to the pictures I would say that the Holley is only slightly rich and I need to bring timing down to around 14 deg advance from 16 degrees, but really the plug is very close to looking like the picture of best. Now here is a question for the BG tech! If the BG Mighty Demon carb I have listed on eBay don't sell can I replace the metering blocks with a set that is leaner or is changing the jets all that can be done?
07-20-2008 04:24 PM
camaro freak
We Got It.....

Awesome plug info link... Ok folks we got it! I tested the distributor and wires and all was good! I built a spark plug tester using a 24 volt spark ingintor from a furnace and the transformer so I could test each spark plug. As I went from plug to plug I noticed that each spark looked weak. The sparks were orange in color and not like the nice blue spark that came from the wire when I tested it. We got to plug 8 and guess what? NO spark!!! None at all!!! So we made a trip to Advance and what the heck lets grab those 5 year warranty E3 plugs at $7 each and see what happens! Well, after laying a patch 25 feet long and burying the speedo I would say we found our problem! I plan to let the motor cool some and then read a few plugs and adjust if necessary. I do however plan to stay with a Holley. I want a 750 double pumper HP carb, I may consider an 850 double pumper after reading the test results from the 383 build that Chevy High Perf magazine got! If someone has a good new or like new Holley like I want, drop me a note in the next few hours, well by 9 pm est and maybe we can work out a deal. The BG carb I have is like new, honestly, we have only put about 100 miles on it. We changed the PV and put reusable blue gaskets on it and that is all we did outside of adjusting it. After 9 pm est it will be on eBay! Thanks to all for the help!!! I hope this thread is helpful to someone else!
07-20-2008 12:18 PM
SSedan64 [QUOTE=camaro freak]When they say a plug has carbon build up, what causes that???

Check here>>

http://www.4secondsflat.com/plug_chart.html

http://www.4secondsflat.com/Spark_plug_reading.html
07-20-2008 12:04 PM
camaro freak
more...

As soon as I can confirm what our problem with this engine is I plan to do something with the carb. I'm thinking that the BG carb is just way too rich for this engine. I'm thinking it is the metering blocks not jetting or PV. The off idle stumble/ flutter happens in park at 1,000 rpm and continues to about 1,800 rpm however when I drive the car and from a stand still nail the peddle to the floor the car stumbles and flutters all the way down the road until I let off the peddle and then it stalls out dead and is hard to restart! I pulled the plugs and one looks heavy carbon on it. All look black sooty at base, 4 have slight dark tan on the center and electrode, and 2 are slightly wet. These NGK plugs have 100 miles on them and they look like they have 10,000 miles of running rich on them. We are using a friends Holley 750 right now. We would like to stay with a double pumper carb for tune ability! When they say a plug has carbon build up, what causes that???
07-20-2008 10:52 AM
ssmonty What RPM is the engine running rough at? The specs for that cam are for 2200-5800rpm. If you don't like the way it runs below 2200rpm then you have a cam with too much duration. Have you tried to recurve the distributor. That cams gonna need alot more initial timing than 10*. Buy a kit that will limit the distributor's mechanical advance to say 12*-14* max. Thats just the distributor's mechanical adv. range.(no vac. adv connected) Needs bushings to limit the mech. range.(not sure if there is a kit for stock HEI to limit amount of mech. adv.. I know there are spring kits to change the rate of adv.) Verify with a timing tape. Say you have 10* initial at idle with a timing light, rev it up to 3000rpm and the timing light should indicate 22*-24* if you have it limited correctly. Then adjust your initial timing to say 18* at idle by turning the distributor. Then verify with a timing light that the total timing(18* initial plus 14* dist. mech adv.) is no more than 32*@3000rpm.(no vac. adv. connected). Leave the vac. adv. disconnected temporarily, then see if it runs better on the road with out detonating.(listen for ping and check plugs for small black specs, if you have ether, you need to back off the initial or mech, or both, or slow down the mech. with heavier springs ) You will have to fine tune both initial adv. and mech adv. to get best tune, takes some time to get it just right, but these settings should get you running better without getting into detonation at WOT just to see if its your timing causing rough running. Try it! Then you will have to hook up the vac. adv. and play with it. You will probably have to get a different vac. can for the dist. that limits its adv. and when it comes in. Thats a whole other issue. You may have to get an MSD dist. for its tuning versatility?(mech. adv.)
Then you have to dial in the carb, but get the timing done 1st. You may have to get a higher stall converter/lower rear gears if you can't get it to run at low rpms to your satisfaction after getting the timing right.
Just my 2cents.
ssmonty
07-20-2008 09:57 AM
eric302 Before you get rid of the Demon make sure you are getting a good shot of fuel from the accelerator pump. You should be able to see the fuel come out of the squirters when the throttle is activated. If there is no fuel from the squirters check the accelerator pump or the adjustment. I've been there. Just my 2 cents worth.
07-19-2008 05:30 PM
camaro freak
more...

Put the BG Mighty Demon back on car. Still has the same problem. So, I swapped the BG carb for a known to be good 750 Holley. Well, big improvement. The off idle flutter is now just a slight stumble when in park. The engine sounds much better but when I drive it I notice a jarring flutter as I accelerate normally and for a 383 I think my 4 cylinder VUE has much more power. Something isn't right with this engine and I can't figure it out. It feels like a dead cylinder or something. Because the Holley did make a noticeable improvement, I am getting rid of the BG carb (at a big loss) and getting a Holley (much easier to work with and adjust plus better performance for me anyway)! The BG carb is only a year old and I only put about 50 miles on it but I have waisted enough time with it. When the BG carb is on the engine the problem I am having is much worse.
07-17-2008 09:10 PM
camaro freak
BG tech...

Got the carb apart and going through it now. I will check these items. It has a 2,500 rpm stall converter. Upon taking the carb apart I found, on the secondary side only, in the area that the power valve would be a thimble amount of a black jelly looking substance. The primary side was clean as new. Not sure if that would cause our issues or not but I plan to clean it up a install new gaskets. I also switched the power valve to a 45 from the factory 65 because my vacuum is between 10 and 11". I will also increase timing to 16 degrees as advised by the BG hotline and report my results soon. I am concerned though that much over 12 degrees and I will have starting and or run on issues, we will see what happens.
07-17-2008 04:17 PM
Tech @ BG
Quote:
Originally Posted by camaro freak
The vacuum readings were wrong. Tested today with another guage and here is the results:

@ 1,000 rpm 12 deg adv in park its showing a slightly bouncing 14 to 15" vac.

@ 700 rpm in drive with foot on brake its showing a slightly bouncing 10 to 11" vac.

On both test the guage will occasionally drop 2 or 3 numbers then come back to where it was at.

The off idle fluttering stumble is still there. Now if I slowly bring the engine up to 2,000 rpm then nail the peddle to the floor there is no flutter or stumble. It accelerates fast and sounds good. When I nail the peddle I notice the vacuum guage drops to "0" then jumps fast and smoothly up the scale.

With the above vacuum readings what power valve should I be running?
Are you trying to idle completely off the front butterfly? How much of the transfer slot is showing on the front vs the rear? How far open is the idle-eze? If you have the fronts open a lot and the rear closed [butterflies] you may need to open the rears,close the fronts down a little and open the idle-eze up a little. Also how much converter is in it?
07-16-2008 09:55 PM
RippinRon
Quote:
Originally Posted by n-gin
If you had a coolant leak in the engine, the oil will look like the center of a 3 muketeers bars.
Or as I like to say bailey's irish cream
07-16-2008 09:49 PM
camaro freak
more...

The vacuum readings were wrong. Tested today with another guage and here is the results:

@ 1,000 rpm 12 deg adv in park its showing a slightly bouncing 14 to 15" vac.

@ 700 rpm in drive with foot on brake its showing a slightly bouncing 10 to 11" vac.

On both test the guage will occasionally drop 2 or 3 numbers then come back to where it was at.

The off idle fluttering stumble is still there. Now if I slowly bring the engine up to 2,000 rpm then nail the peddle to the floor there is no flutter or stumble. It accelerates fast and sounds good. When I nail the peddle I notice the vacuum guage drops to "0" then jumps fast and smoothly up the scale.

With the above vacuum readings what power valve should I be running?
07-11-2008 09:56 PM
camaro freak
continued...

Ok will play with the timing some more but I really think Im gonna find the problem in the carb. I am gonna try to swap another carb on and see what happens. As for the vacuum readings, well the guage I have is brand new first time used and thats what it shows.
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