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Promax. Paid for and waiting for the phone call....

biomedtechguy

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I got the majority of Promax 6 bbl upgrades available, and likely the couple I missed will be added when I send them my 3 x 2bbls.
My 70 V-code (71 motor) 6 bbl overall runs good. Nice kick in the *** when the outboard carbs open gradually under vacuum, which I can feel the smooth but powerful transition when I am half throttle or so and let the RPMs climb, increasing vacuum and transitioning the outboard carbs open vs up shifting w/my standard transmission. Same thing when I stomp it from a dead stop. No stumble or hesitation. I occasionally have some idle weirdness, and the carbs over weeks seem to always creep richer.
Anyway, the point is that after I spent some time tweaking them soon after I got my Roadrunner about 4+ years ago, they have run pretty well.
I am bonkers for the 6 bbl setup, I'm stoked to take them to the next level, and when I top off my future stroker motor with the 6bbl the Promax parts will be invaluable.
I'm getting a dual band wideband O2 sensor and gauge soon as well, and I will finally install the new Carter M6903 high flow fuel pump I've had for 2 years.
 
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Install complete. Those damn silver aluminum fuel fitting to fuel bowl washers sucked for me, 2 out of 3 leaked badly. I replaced them with the factory thin steel washers and that fixed the leaks. Promax is sending me nylon washers, so I may try them, but I may not anytime soon since the leaks are gone.
I still have to adjust the 6 idle mixture screws, but I took a test drive and it was pretty good, just still rich at idle.
Also installed the Carter M6903 mech fuel pump which I really like so far.
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Install complete. Those damn silver aluminum fuel fitting to fuel bowl washers sucked for me, 2 out of 3 leaked badly. I replaced them with the factory thin steel washers and that fixed the leaks. Promax is sending me nylon washers, so I may try them, but I may not anytime soon since the leaks are gone.
I still have to adjust the 6 idle mixture screws, but I took a test drive and it was pretty good, just still rich at idle.
Also installed the Carter M6903 mech fuel pump which I really like so far.
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Love this car , nice work man
 
Love this car , nice work man
Thanks Pete.
After the date of the video I had a whole week of drive time w/the new Promax modded Holley carbs. Something is wrong because other when I first got my car and the outboard carbs were not opening (required a slight adjustment of the threaded rods that connect to the throttle plates) other than then, my car has never run worse.
:BangHead::cursin:
I have a bad stutter that I have had a week to evaluate and seethe over.
My thoughts are some debris got through to the carb(s) so I am going to disassemble and clean.
I'll follow up (unlike Promax)
EDIT:
To be fair to Promax, I just got off the phone with them. They were out of town at an event.
He made some suggestions, I will follow up with a post.
 
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I got a Promax metering block last year. I’ve heard good things and wanted to try it out. Car ran terrible and wouldn’t stay running. Put the stock one back in and the Promax one has been sitting on the shelf ever since.
I know a guy that bought Promax stuff years ago and loves it. When he ordered it they wanted to know all about his car and how the engine was built. When I ordered mine they didn’t ask anything. The metering block I got is different than the one he got. His also has Promax engraved on the side and mine does not. Before I ordered mine I was unable to reach anybody at Promax for a few months. I think something has changed in that time period. I could be wrong but I won’t be buying anything else from Promax.
I’ve tested about 5 or 6 different metering blocks for the six pack set up and found that with good fuel nothing beats the factory one. With pump gas I ran one from a four barrrl carb, (can’t recall the part number off hand).
Good luck to you, hope it works out well.
 
Nice work, hope you figure it out.

I need a return spring like you're useing. Any info, measurements?
 
Thanks Pete.
After the date of the video I had a whole week of drive time w/the new Promax modded Holley carbs. Something is wrong because other when I first got my car and the outboard carbs were not opening (required a slight adjustment of the threaded rods that connect to the throttle plates) other than then, my car has never run worse.
:BangHead::cursin:
I have a bad stutter that I have had a week to evaluate and seethe over.
My thoughts are some debris got through to the carb(s) so I am going to disassemble and clean.
I'll follow up (unlike Promax)
EDIT:
To be fair to Promax, I just got off the phone with them. They were out of town at an event.
He made some suggestions, I will follow up with a post.

That's too bad especially when you wait for something to arrive then it shows up and doesn't work .
Could it be lack of fuel - stutter ?, different carbs while cruising needs different timing ?
Hose collapsed or kink inside when installing ?
What happens when floored ?
 
I just got off the phone with Promax.
I have 3 glass sight plugs now and I am going to check the float levels on all 3 carbs. I have decided to check the inline fuel filter as well for debris for peace of mind. Someone recommended and I should have done this as well-flush the new lower and upper fuel lines before hooking them up to the carbs.
If the float levels are ok or after adjusting it still runs bad I am going to readjust the idle mixture screws.
If that doesn't help I will disassemble and clean out the fuel bowls, needles and seats, and the center Promax metering block.
I will follow up.
measurements
No info on the return spring, it came with the car. I will measure when I can. Playing catch up with work. I can't even fool with the carbs right now.
 
I believe the promax block is an engraved BLP block. Advantage is if you would need different IFR’s or PVCR’s they are adjustable. If the original primary block happens to be suited for the combo, there is absolutely no advantage to the aftermarket block other than it looks cool.
 
My experience with Promax was not good so beware. They talk a good game but they do not back anything up when they work on something and it isn't right. They redid a 69 Carter AVS carb for me few years ago. Did not work when installed back on my Bee and they basically washed their hands of it and charged me quite a bit to rework it. Got their money and ran basically. As I said beware.
 
Did it work ? I learn so much stuff on this site ..
I still haven't got back on them. Lots of work to do with my one man (me) business, but if I get a combination of good weather and time, or at least time, I can start on trying to fix them.
I'll be sure to post, I promise!
 
So your now looking at the EFI 6 pak options they look nice but are they really worth it ?
I hear maybe 1-2 mpg better but do offer quicker starting and when the car starts after hot it's quicker .
 
So your now looking at the EFI 6 pak options they look nice but are they really worth it ?
I hear maybe 1-2 mpg better but do offer quicker starting and when the car starts after hot it's quicker .
Actually the practical guarantee of maximum performance is what has my interest.
As far as "worth it" goes, given how much money I've spent buying the car and doing upgrades, with many more to follow, getting the most out of my investments is critical, and I'm not sure I'll ever "be there" with carburetors.
I'm not done with my Holley/Promax carbs yet, far from it. I haven't had time to try to fix the problems I've had since I got them back.
I hear maybe 1-2 mpg better
That is something I think about in my Dodge Caravan.
 
I like it the car it is awesome and I get the tunability with EFI . I read somewhere you worked for GE that's where I still am till were sold .
Waiting to see what's next on you ride .
 
I like it the car it is awesome and I get the tunability with EFI .
You have the 3x2 FiTech system? Or??
I read somewhere you worked for GE that's where I still am till were sold .
I did...my 1st 6 months as a Biomedical Technician. More like indentured servant...
My area supervisor (who had a master's degree in management, and would tell anyone, everyone several times a day) was a crappy biomed tech and a corporate ladder climber who used other people's necks and the daggers stuck in their backs as the rungs "to the top".
I saw skilled Biomedical engineers who were within 18 months or less of retirement being suddenly **** on by management so badly it was obvious that GE was trying to force them out early, and that was after those employees sacrificed the best years of their lives on the corporate altar, broken marriages and relationships all destroyed for "dedication to GE" because, after all, GE was going to take care of them in their retirement...
The letters of recommendation and praise from charge nurses and staff I brought to my "performance review" weren't even read they were so anxious to get to the rock throwing party where I was the target of abstract bullshit that is indefensible because it's "feelings" and abstractions-nothing based on actual performance.
My departure from GE (GE-the bastard child of "The Borg" from Star Trek and the Sith Lord of Star Wars) was the best day of my professional life.
I'm not bitter, I'm GRATEFUL that I have my own business and do things the RIGHT way and I am emotionally and financially rewarded for my work.
Yeah, I worked for GE...Lol.
 
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