Diagnose Latest Build 440 6Pack ?!?!?

Moparts World. I've wrapped up my latest resto on my 71 Challenger 440 6 pack. Car was stripped down to a bare shell and a basketcase project. So I feel great I saved it from the grave and it's a great feeling to drive this thing down the road! But I don't quite feel it's preforming like I planned for it. It's not a numbers car, although my goal was as stock appearing as possible it does have headers and 4 core alum. radiator. I'll give the spec's on it below and history below and if you would help me trouble shoot this build and see if anything glaring pops out at you.

Tanny woes: The first drive in this thing yielded some transmission issues. It wouldn't shift out of 1st gear, pulling the trans and going thru it we found a port was plugged preventing pressure to allow the 1st to 2nd shift. One thing I recall during the first run, car felt like I thought it would in 1st, didn't take much to spin the tires, just a tap of the pedal. So even though everything was rebuilt and new in the tranny, I had bought a full kit for it and put it all in new and upgrade low/reverse band and kickdown lever to 5.0 ratio. Car now shifts into all gears, and drives fine. It will do a burnout, but it's not as scary as I figured it would be with 440 six pack. Car seems "labored" or sluggish". Seems something is robbing it of power. Not alot of low end power, but if you stomp on it while in 3rd gear it pulls hard on the top end. I planned for more torque and low end power than top end power? He's what's in it that I can think of off the top of my head. I'm not sure if it's converter, gear, bad tranny build, bad valve body, timming etc. . .

- 440 .040 over with KB pistons, 915 closed chamber heads that have been milled a tad and slight port/bowl work. 2.14/1.84 valves I believe. Lunati voodoo hydraulic .534/.513 cam (builder said would give 10.1 comp with piston/head combo)
- 6 pack is the direction connection aftermarket mech set
- 3,000 stall converter (Hughes, new)
- 3:55 gear
- 275/60 R 15 tires
-727 has factory valve body, it's a 64 model, but was an old race tranny. Had HD drum and other items to "beef" it up. I'm not a tranny wiz, but have been told by multiple people it has the right stuff in it. But recently had to tighten low/reverse band. Drove around a summer with it to loose.

are you sure your transmission has a 64 valvebody ? those were cable operated and had a different case and tailshaft casting.[among other drastic differences.]
perhaps you meant a 74 valvebody ?

I had a 64 Polara 500 2dr hardtop with a floor shifted 727. That tranny was not cable shifted. He could have one of those.

Just sayin'

I know the body of the trans is a 64. I believe at the time when we looked at the valve body the date code on it matched up, but I can't recall now. The trans has been modified plenty, it's not a stock trans that has just been rebuilt. I bought it already rebuilt from someone here on Moparts years ago. But pretty sure it had a manual valve body in it with that port being plugged.

The 64 council shifted 727s were still cable shift. Just from the shifter instead of the pushbuttons.

You want some low end grunt/balls from that combo, dump that pig of a converter, get yourself into the 1800-2000 RPM stall range before even dialing in the carbs/timing IMHO

Mike

So you are suggesting he put a stock converter in his car? I completely disagree. 3000 stall sounds about right to me. I can't vouch for the quality of Hughes products though. I'm assuming the OP has the this cam: https://www.summitracing.com/parts/lun-10230704/overview/make/plymouth Combo ought to be good for 12s with traction.

That's the can I'm running. Traction is no problem. It won't really spin em. If you power brake, it'll do a burnout. But nothing glamorous

You don’t mention who built the engine.

Regardless if these parts play together nicely or not:

Was cam degreed in? If so, what is it set at?
Was TDC checked against the damper on the engine?
What is the total timing set at, and when does it come in? What is your total timing?
Did you check for wide open throttle. Not only the center carb but the front and rear?
Did you check compression - if so what Is it?

I built the engine (not my first engine build), but had a fellow member here/drag racer dial in the cam. He checked TDC, set the cam per the card and no offset in degrees. Verified what he did to with degree wheel etc.
TDC checked with damper and piston travel
Timing is one thing I changed, when we set it, we set it at 36 at 2,000 rpm, that was without vacuum advance set up. Plugged in the vac. ad. and ran it for awhile. Check it with vac. ad. hooked up and once you leave idle it would just go into outter space off the damper with increase of RPM. So plugged vacuum advance and it holds 36 all the way up to 3,000 ish when we checked it. I did put the light weight springs in the distributor.
WOT seems right on, pedal does give you WOT. I could adjust when outboards come in since they are mech on progressive linkage but I haven't.
Did not verify compression

The motor runs fine, idles well, great throttle response, seems normal and uncapped it's LOUD, like my small block drag car was. The one and only thing I felt uneasy about with the engine was I bought pushrods from 440 source that are for hydraulic cam, and mech rockers. I don't have factory hyd rockers. They are isky iron rockers. I didn't do a custom push rod length check. But the length of adjuster screw out of the rocker was good.
Could add I have magnaflow 2-1/2 exhaust with x pipe.

With vacuum advance unplugged from distributor (and the line plugged) what is the initial advance?

It will read 36-37 degrees no matter if your at idle or come up in RPM. I think because the light weight springs

I would try setting the timing at 18* at idle with the vacuum advance disconnected and the vacuum line plugged.

With 10:1 and iron heads, I would expect the motor to ping badly with that much initial. Sometimes way over advanced can kill power. This is definitely an area to improve in your combo (hot street engine). As stated 18-22 initial with the remainder in by 2500 or so. Timing curve can make a big difference in the power characteristics.

I had a set of Mr Gasket springs in a single point dist back in the 80s that reached full advance at 1100 or thereabouts.

My bet it's a combination of items. As a test disconnect the linkage from the outer carbs. Run just on the center carb. My bet is it'll wake up the bottom big time. The solid carb linkage is not the ticket for low end street use If this does indead fix it, consider going back to the factory vacuum secondary linkage. Even the factory stuff can be adjusted to open to quick if you run the lightest springs in the vacuum pods.
Doug

I'll try the timing and carb adjustments listed. Thanks guys!

If you're still having problems with this, use the lightest of the stock springs and only one of the lightweight springs and leave the vacuum advance capped off, this should solve the problem of it going to full advance at idle. Set your total at 36-38.

Stumpy is right on, that cam needs to be advanced at idle. If it then has too much total advance you'll need to restrict that with the slots in the distributor (usually by shortening them by welding and filing until you get the desired total advance)

Is that what you meant to say? If so, you might want to add some clarification for the OP.

Another 6 pak help thread with ineffective technical support, it pains me that lots of good info has been posted many times before but no one can remember anything

OP
The carbs are not set up properly and the timing/distributor suggestions are for race cars
There is nothing wrong with your converter choice.

There is an old tuning guide that works on the net over at the lift off hood playground that would be very beneficial to your request for technical support.
I no longer provide whatever you want to call it advice or tech support as in years past - I cannot support this place due to the problems with the ads and lack of response from management.
good luck

My meaning is with that cam the initial timing needs to be around 18 degrees like Stumpy said and, I wouldn't use the 1800 stall converter with that cam, stay with the 3,000 stall.

I've never ran and tuned a set of the mechanical carbs, I have used, tuned and ended up liking the stock OEM carbs on several different 440 type motor and one low deck 400 block 518 C.I. pump gas stroker motor.
That being said you need to go through the basics first to get the best performance out of your parts, start with making sure that all three carbs are all the way open with the gas pedal on the floor with you in the driver seat
Next is to fix the distributor so it has a little advance in it, say 20 crankshaft degrees so you can set the initial(idle) timing from 14 to 16 degrees and have 34 to 36 degrees total timing
The next thing is to make sure the carbs are not running out of fuel at WOT, the mechanical carbs have a lot smaller fuel bowls on them and I've been told they are a problem to keep enough fuel in them to run good at WOT To do that you will need a fuel pressure gauge( 0 to15 lbs.) you can see while driving, if it drops below 1.0 lbs. at WOT you need to fix that Check the needle and seat size, use Holley viton tip .110 or bigger
Six packs can be made to run excellent with work, find out what is wrong and go from there
Be careful on what you end up with, don't hurt yourself and the car from loosing control of the car due to much tire spinning
Good luck, let us know what you find out

Guys, I see someone brought this back from awhile ago. Sadly the car has been in hibernation! I've not tinkered on anything. I did purchase a new converter, if it doesn't help it'll get moved to the next build. I plan to look closely at the carbs once good weather hits.