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Discussion Starter · #3,001 · (Edited)
That is interesting. With the Big Mutha Thumper cam in my 428 I'm getting a steady 10-11" at a 900-1000 rpm idle. This was taken shortly after I had the heads done. View attachment 107623
Is your plenum open to both carbs or are they divided or isolated to each carb?
im gonna try another vacuum port. See what it reads.
 

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The base port is full manifold vacuum, but the port on the metering block is timed vacuum and wont read much at idle. I use the base port to connect my vacuum gauge.

 

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Discussion Starter · #3,003 · (Edited)
The base port is full manifold vacuum, but the port on the metering block is timed vacuum and wont read much at idle. I use the base port to connect my vacuum gauge.

Exactly. The base is where I tapped the line for the gauge. I’m wondering because of the open plenum would each carb draw half the normal 10 hg. Interesting indeed. I’m going to take a reading on the primary carb tonight. If it shows 5 again I will be looking for the lowest power valve I have. I will let you guys know how it works out. I had it idling at about 7-800 rpm When I checked. So my game plan is to swap jets upsized 2 numbers and to maybe replace my powervalve to a lower number Depending on my vacuum reading before I tear it apart.
 

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Since that outlet is manifold vacuum, I'd expect it to be the same at either carb, since they share a common plenum.
 

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Is your plenum open to both carbs or are they divided or isolated to each carb?
im gonna try another vacuum port. See what it reads.
My manifold is open plenum Mario. As the photo shows I have a line coming from the large vacuum nipple at the base of each carb to a T fitting with the gauge.
 

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Discussion Starter · #3,006 ·
So I just checked my vacuum at the primary carb and it’s at 6 hg. My power valve has to go much lower.
 

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Discussion Starter · #3,007 · (Edited)
I pulled the bowl and my power valve is a 6.5. Not gonna work with the vacuum I show on the gauge. I had a bunch of 5.5’s and 4.5’s and then I saw a 2.5. That’s what I want to start. I decided to leave my jetting alone and see what happens with the power valve change. If it goes according to plan I will need to add bigger jets to fix the cleanup with the right power valve Installed. And holding true to my prediction it did. Mixture screws hardly had any effect so I need to go up in size. But it’s crisp and cleaner than before. After the cruise night tonight I will pull a plug to see if it’s still loaded with soot.
after all was done I got close to 10 on the gauge. Then I had to idle it down again which yielded about 7-8 on the gauge. I also moved the distributor to the best vacuum at idle. Shut it down and let it sit and it started without hot starter drag from too much initial timing. One more jet change and I should be good for a while.
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Discussion Starter · #3,008 ·
Now a change of subject. After fixing my speedo I became fixated on getting mph close to reality. I was too fast. I moved up to the largest gear and housing to accommodate a 45 gear. I was still 15-20 mph fast. After looking through my spare gear parts I found an adapter. I spun one side and marked the output side and found it to be 1: .75 so it will slow down the cable even more for me. I am going to test it tonight. Not sure how much slower it will go. Stay fixated on the speedo housing. Pay no attention to that ugly weld at the frame.
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Discussion Starter · #3,009 ·
Well take it from me. Don’t move your distributor to the highest vacuum. It was so advanced that I couldn‘t start my car after pulling in to the cruise night parking space. I had to shut the ignition switch off and spin the engine then hit the switch to fire. Scared me. I thought my battery was dead when I got there. When I got home I moved the distributor until I got a good fast fire up. I should be ok there. I did pull a plug and after going for a blast on the parkway on the way home. Looked like it was starting to clean up. Black soot is turning brown again. I’ll have to pull all the plugs and clean them good.
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Discussion Starter · #3,010 ·
Well it turns out I had a bad alternator This morning and couldn’t make the show. Opened it up and put in a new regulator and diode trio and slapped it back together. NG again. So I removed the new parts and ran to pep boys To buy a reman unit. Put it on and all was well again. Took a ride to the beach show and stopped dead in my tracks With a mile to go idling at 190 deg and slow climbing. Gas is at about 1/2 tank. I started sweating it out. There were 3 lanes into one merging into the show.
had to abort. Made the turn around and traffic started moving ok. All of a sudden a late model Silverado comes up to me Gives me thumbs up and opens his exhaust and hammers his gas Peddle when I hear a thunderous supercharger out the exhaust so i said what the heck let me hit it and see. He jumped ahead of me and I stayed with him but couldn’t catch him And let off the gas pedal. I guess I will never know if I could have caught him or not. But man was that LS truck fast.
 
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Bummer on the aborted trip to the show Mario!! Always seems things like the alternator go when it's the worst time to happen!
 

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You know what Mario, doesn't matter what someone does to a late model truck or car they still won't have the cool factor that an MG gasser has!!
 

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Discussion Starter · #3,013 ·
You know what Mario, doesn't matter what someone does to a late model truck or car they still won't have the cool factor that an MG gasser has!!
Thanks Steve. Gotta admit that truck was fast. It blasted out the exhaust cutouts. but I’m proud I was keeping pace with him. Scary up there on the top with my car.
 

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Discussion Starter · #3,014 ·
Bummer on the aborted trip to the show Mario!! Always seems things like the alternator go when it's the worst time to happen!
Hey Vall the alternator was my fault. Bone head move. I connect a battery backup 9volt battery for radio memory and drove the car with it connected. Fried the 9volt and never thought that it hurt the alternator. Stupid me.
not only that I thought the timing was too far advanced at the show Saturday night. It was the dead alternator. Not knowing I drove home on battery.
 

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Discussion Starter · #3,015 · (Edited)
Tonight I cleaned 7 out of 8 plugs. Passenger side is tuff To get to. I’ve used sockets, wrenches, and fuel line hose to get to the others, but this one #8 is a pia. I may have to go under the car to get to it. Starter is in the way. who built this car anyway? I have an idea. I’m going to use a 13/16 socket 12 pt and cut a 3/8“ slice out of it on one side only. Slipping it over the sp plug. Find a long enough wrench Marking it and welding it to it so I can break the plug loose. It’ll save me from going under the car.
 

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Have you tried any of the open end spark plug wrenches that come in motorcycle tool kits Mario? I had issues when I had the angle plug aluminum heads on my Austin, and that was the only thing that worked to break a couple loose, or tighten them. Then I used 3/8" hose to spin them out or in.
 

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Discussion Starter · #3,017 ·
Have you tried any of the open end spark plug wrenches that come in motorcycle tool kits Mario? I had issues when I had the angle plug aluminum heads on my Austin, and that was the only thing that worked to break a couple loose, or tighten them. Then I used 3/8" hose to spin them out or in.
I need something similar but short. Box wrench won’t make the hex but a short 12pt could. So I’m thinking of welding a wrench at the end of the socket so I can break it loose. Getting it in after is another challenge. Fuel line is my first go to.
 

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Discussion Starter · #3,018 ·
I got home and went out to the garage and found my son up to his elbows working on his vette. Cool but wasn’t a good time for me to break out the welder and cut off tool. So I did what I could and graciously waited for mike to finish up. Seems his new Holley valve covers came with a coil bracket adapter that didn’t work with his gm coils. He called it quits to do more research. So now I’m ready. I grab a 13/16 short socket and found a weird looking 5/8 proto wrench and started the sacrifice. I cut the socket right at the square drive area. Put it in the vice with the box wrench up against the socket and gave it a couple of welds. Took it off and slid it over the plug and presto I broke the plug loose. Then it was fuel line time to unscrew the sp plug. Cleaned it and put it back in reverse order. Now I’m happy. So happy I’m going to do the jet change. I had 72’s and put in 74’s. Now the mixture screws all the way in will stall the motor at idle. Now to test drive this thing. By the way I used 4.5 gallons to the beach and back. I had 2 gal to spare. 👏😀😀
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Discussion Starter · #3,019 ·
Just uploaded my video. Regular driving from the car show till 8:50 or so. Short burst.

 
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That was great Mario...I noticed you waited till you could see if no one was around....smart
 
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