Alternative carbs and linkage for max wedge?

[stage3]

sounds to me like u have not addressed the vacuum springs under the metering rods yet, if u have dvoraks tuning manual it addresses that,,,and it will run bad until u attend to those,,,,i have tried numerous carbs on my crossram motor and None of them will fine tune like the 3705's. they were made for that set up....i',m running a .670 roller so i have to use the Blue springs, 107 main jets staggered secondarys and 76-47 rods. runs clean at idle and has fuel injection like throttle response.

 

[fmahannah]

Yes I changed the springs first thing because I had to do that on my Javelins due to low vacuum at idle from the cam. Had to use the 3" springs. Only get 6-7" at idle. What is your idle speed?

 

[stage3]

What is your idle speed?

1400 but my metering rod springs still dance just a little. i mite have to cut a couple coils off of them....

 

[fmahannah]

Timing? Just curious. I need to get my idle down to around 950. Thanks

 

[stage3]

Timing? Just curious. I need to get my idle down to around 950. Thanks

36 locked.

 

[fmahannah]

Mine wants at least 32 to be able to idle at 950 without having the transfer slots exposed (and running way too rich because of this). But I am trying to do it with a combination of initial and adjustable vac adv without having mechanical go to far.
It will take a lot of tweaking. Is there any disadvantage to just running locked out (other than fuel economy)? One issue so far is that dropping into park causes idle vacuum to drop so that vac advance is lower than what it takes to kick in
the advance canister. I may just try running locked out instead of having to play with all the factors involved

 

[Geoff 2]

No problem at all running locked timing & any loss of economy would be miniscule.

However, the starter might buck with locked timing. Fixed by buying a 3hp starter, such as MSD DynaForce. There is also the possibility of pinging.
Just try it & see...

 

[stage3]

if u try locked out timing some form of a start retard will be your best friend,,my msd7al3 has it built in. it retards 20 degree;s until the motor hits 600 and up rpm and goes back to full 36 degree's..i havent seen a down side yet, throttle response is quite impressive as i posted above,,good luck.

 

[fmahannah]

I might do that if I can't get the magical combo of static, vac adv, and mechanical to work. Thanks!

 

[fmahannah]

Finally took a test drive ... feels like it is missing under throttle, still not responsive. Tried with and without vac advance. Might swap the Summit distributor back out for the MSD 8546 and try locking it out at 34-36 and see if it makes any difference, but honestly after everything I have tried already I am ready to find an actual mopar mechanic and turn it over to them. Does anyone know of any shops in North Georgia that work on old Mopars?

 

[Geoff 2]

Forrest,
A cross ram intake is never going to be responsive under 3000 rpm & people who tell you otherwise are pulling on something they shouldn't be......
So if that is where you were testing, it is behaving as designed.
These were never designed as street intakes. They were designed to win drag races. Yes, you can compromise but the CR intake will never have the response & flexibility on the street that a modern designed dual plane such as the Edel RPM has. Not what you wanted to hear, I know.....

 

[fmahannah]

Forrest,
A cross ram intake is never going to be responsive under 3000 rpm & people who tell you otherwise are pulling on something they shouldn't be......
So if that is where you were testing, it is behaving as designed.
These were never designed as street intakes. They were designed to win drag races. Yes, you can compromise but the CR intake will never have the response & flexibility on the street that a modern designed dual plane such as the Edel RPM has. Not what you wanted to hear, I know.....

Yeah I understand that, but it is just not running hardly at all under load. It actually ran much better (but very rich) before I started messing with it.

 

[stage3]

Forrest,
A cross ram intake is never going to be responsive under 3000 rpm & people who tell you otherwise are pulling on something they shouldn't be......

mine is...................................................

 

[Geoff 2]

I thought I would address the nonsense that the cross ram 426 wedges were streetable engines & released by Chry for street driving. I have a large collection of original magazine articles of the era [ not re-hashed Google stuff ]. So I will give some quotes on these engines.
Two important points need to be remembered with these engines:
- not even Chrysler's brilliant engineering could overcome the laws of physics [ LOP ]. And the LOP say that huge plenum volumes such as the max wedge intake are slugs at lower rpms, which makes them poor street performers.
- they came with either 11:1 & 13.5:1 CR. Lowering the CR to use with today's fuel makes an engine that already was dead-ish at low rpms, even worse.

[1] HRM Jan, 63:
'The high comp engine is strictly a 1/4 mile sprinter & not designed for street use. Plym recommends that full throttle bursts be limited to 15 secs. The 11:1 engine can be driven on the street without any serious consequences but it is not recommended that they receive this kind of operation as a steady diet.....the engine is a thoroughbred designed for the track...'

[2] CarCraft Nov 63.
' Like its predecessor, this 426 racing power plant is designed & built expressly for use in supervised acceleration trials. Because it does not offer the stable, even idling of other high performance options offered by Chry Corp, the new 426 is not recommended for every day driving.........The intake manifold is tuned to increased output in the higher speed ranges above 4000 rpm.


[3] PHR 1963.
'The high CR [13.5 ] makes the engine so detonation prone.......normal idle speed is 1000 rpm warm, but do not expect it idle this way when it is cold. Throttle response is so unpredictable when you try & get way on a cold morning........ the car is is a highly specialized machine & should not be looked upon as a passenger vehicle'.