TUNING A SIX PACK

[Frustration]

The photos below are of actual Holley orifice sizes compared to their jet number. the number does NOT necessarily represent the ID. I measured all of my jets with a pin-gauge to get the hand-written version. After doing all that work, I found the Pro Maxx one below. This is needed because the diagrams in my above post call out drilling the metering plate, not installing jets (when talking about the outboard carbs). Good luck, and reply back when you get it installed and running. Tom

 

[Frustration]

Last one I have was from a member on here...maybe 68 HEMI GTS?? I too was asking all kinds of questions about this intake when I was working on it. I received the screen shot below from a member that ran the intake with mechanical outboard carbs. Not sure what the changes would be like if you modified your vacuum secondary carbs in this manner. It probably would not work well. If someone has mechanical carbs for this intake, the notes below are likely pretty good, being as it was on an NHRA car.

 

[biomedtechguy]

Tom,
Thanks a LOT for all of the info.
I emailed and then actually spoke with a guy who posted pix of some non-Chrysler Performance mods he did, after trying the Chrysler Performance bulletin mods.
I also tracked down the ONLY copy of the entire Chrysler Performance book that has ALL of the mods for ALL of the aftermarket intake manifolds at that time.
I'll follow up.

 

[biomedtechguy]

Here's some pix of my Weiand P3690982 6bbl intake. I think it's a fine specimen, and it appears as though the only mods are "radiused intake runners to the floor" which is recommended by the Chrysler bulletin, and eliminated the sharp original 90 degree corners:

 

[66Satellite47]

Looks great, be sure to do the lid mod on the rear drivers side (#8), then you figure out the "popsicle sticks". Your Promax carbs should make the jetting easier to figure out.

 

[biomedtechguy]

be sure to do the lid mod on the rear drivers side (#8)

The elliptical grinding away of lid material.

 

[Frustration]

One other thing I forgot to mention. Since I was running Max Wedge heads on my combo, I had a buddy's dad weld the top of the runner area to have the ports opened up to MW size.

 

[biomedtechguy]

One other thing I forgot to mention. Since I was running Max Wedge heads on my combo, I had a buddy's dad weld the top of the runner area to have the ports opened up to MW size.

That's HUGE information!
One of my self-imposed challenges re: my stroker motor plans is my own insistence that my V-code Roadrunner keep a 3x2 intake. I wasn't sure the Weiand could accommodate Max Wedge ports, although I figured someone could make that happen.
Thanks again, very much, Tom!

 

[Frustration]

That's HUGE information!
One of my self-imposed challenges re: my stroker motor plans is my own insistence that my V-code Roadrunner keep a 3x2 intake. I wasn't sure the Weiand could accommodate Max Wedge ports, although I figured someone could make that happen.
Thanks again, very much, Tom!

No problem at all. Just be clear, the intake needed additional aluminum welded to the lip of the intake in order to machine it for MW ports. It would NOT accomodate the port mods without the extra material. Please keep us posted on how this works for you. Shoot us a picture of said V-Code road runner. Good luck!

 

[biomedtechguy]

Shoot us a picture of said V-Code road runner.

 

[biomedtechguy]

Not just for show...

 

[Frustration]

Not just for show...

Nice! What did it run? I doubt you'll get that manifold to fit under the stock hood with an air cleaner on it. Mine is a '69 with a lift-off hood.

 

[biomedtechguy]

What did it run?

I think back a few years ago, when that video was shot, mid 13s?
I have a bunch of parts ready to be installed, and many address traction problems at the launch. I should be in the high 12s.

I doubt you'll get that manifold to fit under the stock hood with an air cleaner on it.

I have been promised by an uninvested 3rd party that it should fit.
I still have to drag my *** out to the garage and swap the Weiand in for the aluminum 6bbl intake on it now.
Thanks.

 

[ns1rm21]

Hello everybody. On page one one post said “ block off the outer air bleed and if the idle goes up its running lean”. A little later on also on page one somebody said” block off the air bleed and if the idle goes up it’s running rich”.....which one is it??

 

[biomedtechguy]

Hello everybody. On page one one post said “ block off the outer air bleed and if the idle goes up its running lean”. A little later on also on page one somebody said” block off the air bleed and if the idle goes up it’s running rich”.....which one is it??

THIS out of everything I've learned about getting a 6bbl setup to run better, to IDLE so MUCH better, THIS IS MY 6BBL EPIPHANY!
It is absolutely, definitely THIS:

 

[66Satellite47]

Bio, I also remind you to check/adjust the end carb idle opening settings. No sure how your Promax setup is, but on my OEM end carbs the Mopar info you posted, adjusting the end carb idle screws also needed a slight adjustment to the idle position screws under the baseplate. Those combine made an amazing difference in my off the line response (drag car). I suspect even more important for street performance.

 

[Frustration]

Bio, I also remind you to check/adjust the end carb idle opening settings. No sure how your Promax setup is, but on my OEM end carbs the Mopar info you posted, adjusting the end carb idle screws also needed a slight adjustment to the idle position screws under the baseplate. Those combine made an amazing difference in my off the line response (drag car). I suspect even more important for street performance.

66, Are you talking about the adjustment in the rod that opens the secondaries? Not sure what you're talking about in this post, but I'm listening closely. As another question, Bio posted about removing the lead plugs and opening the air/fuel mixture 1/8 turn. I'm guessing that's an additional 1/8 turn from where it was set at the factory. Anyone know how far out that is from completely closed? I'm guessing roughly 3/4-1 turn out? I've been messing with my setup for the past week or two. This note may have messed me up. I tried to run them 1/8 turn out (from seated) and it didn't like that at all.

 

[biomedtechguy]

Bio, I also remind you to check/adjust the end carb idle opening settings. No sure how your Promax setup is, but on my OEM end carbs the Mopar info you posted, adjusting the end carb idle screws also needed a slight adjustment to the idle position screws under the baseplate. Those combine made an amazing difference in my off the line response (drag car). I suspect even more important for street performance.

"the end carb idle opening settings"
Can you run that by me again please?

 

[biomedtechguy]

opening the air/fuel mixture 1/8 turn. I'm guessing that's an additional 1/8 turn from where it was set at the factory. Anyone know how far out that is from completely closed?

The MOST IMPORTANT thing is to make the outboard idle mixture screw adjustments according to the typed instructions, that is putting your finger tip on an outermost air idle bleed hole. LISTEN/WATCH the RPMs (I use a backdial tach on a timing light) and adjust the outboard carbs idle mixture screws for fastest idle.
If the center carb's adjustments are whack, that may make working with the outer carbs trickier.
For me, the moment that changed "my life w/a 6bbl", was learning how to tell if the outboard carbs were too rich or lean at idle.

 

[66Satellite47]

I was trying to say that the throttle blade position on the end carbs with them closed, is also adjustable on the OEM baseplates by little screws under the baseplate. My best results included adjusting both the mixture screws & the blade position. One more variable, but it sure helped with idle quality AND the transition. A very small change in the blade position really helped with the idle mixture adjustment. The covering the air bleed is a great indicator for which direction. This was with a .585 lift 260*@.050 cam.