Looking for advice on a starting point on tuning.

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Doosterfy

Doosterfy

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Well its taken a long time but I'm finally getting close to getting my 440 Duster running. I have not tuned or raced any cars since the 90s and I have never even driven a big block Mopar, let alone tune one, so I'm hoping to get some input on where to start off. The engine is a .030 over stock stroke 440. It has cnc Stealth heads that have been milled .050 so the chambers should be somewhere around 73 to 75 cc. the pistons are flat tops and it is zero decked so it should be just over 11 to 1 comp. The cam is a Comp solid street roller with .582 lift and 254 @.050 intake and .588 lift and 260 @ .050 duration exhaust. It has an OOTB Torker II intake and a Holley 850 double pumper and no carb spacer to start off because I want to try and keep the flat hood and run an air cleaner. The bad part is I'm using Schumacher try-Ys but I did modify them by upping the collectors to 3 inch and I'm running a complete 3 inch exhuast out to the rear with two chamber style mufflers and Dyno Max race bullets in the tail pipes to act as resonators. I have an MSD billet distributor with mechanical advance and I set it to provide 21 degrees all in by 2500. Obviuosly I need at least 93 octane fuel. My questions are; What initial acvance? I'm thinking somewhere around 15 to give a total of 36. What jets should I start with? The carb has a 30cc acc pump on the primaries and a 50cc pump on the secondaries. The last thing I'm not sure about is crank case ventilation. Is a PCV valve the way to go or should I be running a breather cap in each valve cover with hoses going to some kind of catch cans? I'm also using an MSD 6AL2 box. I've got that little kid on Chrismas Eve feeling in my stomach and I'm hoping to get a good starting point to work off of. Thanks in advance.
 
Your going to need a lot more initial timing. I'm thinking 22* or even more. I am still a novice but I just went thru this myself. Took the advice of members here and its paid off. Keep feeding it advance till it starts kicking back on the starter or you have a cranking probe then back it off 2*. Then set fuel pressure and set floats. Those are the very first things
 
younggun2.0 said:
Your going to need a lot more initial timing. I'm thinking 22* or even more. I am still a novice but I just went thru this myself. Took the advice of members here and its paid off. Keep feeding it advance till it starts kicking back on the starter or you have a cranking probe then back it off 2*. Then set fuel pressure and set floats. Those are the very first things
Click to expand...
22 initial? Man that sounds like an awful lot of advance. With 21 degrees in the dist, that would mean 43 total. Are you sayin to run alot of initial and take some out of
the distributor advance? I can easily change the amount and rate in the distributor.
 
Young guns car cleaned up nicely once the timing was good, and it's something you'll have to work with over time. If this is your first time driving your new setup, your starting point may be pretty decent for now. That's some fairly high compression to deal with on pump gas until you get some drive time on it to see what it needs.

As far as the carb, is it a unmodified 850? Does it have all the out of the box parts? Jets, nozzles power valves and such. I would assume a list #4781, but may be a newer version. If so, post that number.
 
Install the exhaust vac kit.... No PCV
Vacuum pump would be best to a puck can... But that's pricey...
Also Try locking the dist @ 34*
Good Converter I hope? leave around 4000rpm if it will hook?
Carb... Square up the pumps and squiters... Square up the 4 corners maybe to like 78's for jets...
Just my 2 cents
Good Luck
 
OldmanRick said:
Young guns car cleaned up nicely once the timing was good, and it's something you'll have to work with over time. If this is your first time driving your new setup, your starting point may be pretty decent for now. That's some fairly high compression to deal with on pump gas until you get some drive time on it to see what it needs.

As far as the carb, is it a unmodified 850? Does it have all the out of the box parts? Jets, nozzles power valves and such. I would assume a list #4781, but may be a newer version. If so, post that number.
Click to expand...
The carb is used off of ebay. It looks fairly new and ther were no jet extentions installed. I'll see if I can get the number off of it. I also bought one of those fancy center sections with no choke horn and the contoured body but I'm not using it until I've gotten the most out of the stoc
k piece. I need to be able to quantify any gains or losses it brings.
 
I understand where your coming from "racerhog", but I believe that may be a bit much for a street car, unless it's a very limited use piece.
 
Doosterfy said:
The carb is used off of ebay. It looks fairly new and ther were no jet extentions installed. I'll see if I can get the number off of it. I also bought one of those fancy center sections with no choke horn and the contoured body but I'm not using it until I've gotten the most out of the stoc
k piece. I need to be able to quantify any gains or losses it brings.
Click to expand...

OldmanRick said:
I understand where your coming from "racerhog", but I believe that may be a bit much for a street car, unless it's a very limited use piece.
Click to expand...

Gotcha "D"...

Guess I should have asked if this is a race only piece?......:mrgreen:.
 
racerhog said:
Install the exhaust vac kit.... No PCV
Vacuum pump would be best to a puck can... But that's pricey...
Also Try locking the dist @ 34*
Good Converter I hope? leave around 4000rpm if it will hook?
Carb... Square up the pumps and squiters... Square up the 4 corners maybe to like 78's for jets...
Just my 2 cents
Good Luck
Click to expand...
The converte is a PTC 9.5 inch 4000 stall. Square up the pumps? Do you mean run both 30cc or both 50cc? Also if I lock it at 34 do you mean 34 with no mech advance? won't that be a problem to start? The car IS going to get driven on the street to cruise nights and some shows. Probly 20 to 40 mile trips now and then. As far as the ex vac kit, I thought those only work with open exhaust. I can use it with an exhaust? Vacuum pump is out of the question, the price is nuts and thats just too far into race car type stuff for me. Even though I have a bunch of parts, the car is closer to a street car. Springs in stock location with Cal tracs, no fenderwell headers, no gutting at all, heater, wipers all that stuff remains. I'm even running a Clay Smith mechanical fuel pump.
 
Doosterfy said:
22 initial? Man that sounds like an awful lot of advance. With 21 degrees in the dist, that would mean 43 total. Are you sayin to run alot of initial and take some out of
the distributor advance? I can easily change the amount and rate in the distributor.
Click to expand...

I know it sounds crazy but my 383 has a smaller cam it was a total dog with 12* initial. I got mine at 22* initial and limit to 36* total and it loved it. Starts with a flick of the key and runs like a raped ape. I had a eye burning rich condition that was helped dramitically by tuning the timing. Also check your plug gap. Hotter ignition systems run a lot bigger gap. I have all msd ignition and run my plugs at.050.
 
Even my 318, which has a very mild cam, about the same as a 340 cam likes 15--17 initial. I've got 20? in the distributor.
 
Doosterfy said:
Also if I lock it at 34 do you mean 34 with no mech advance? won't that be a problem to start? The car IS going to get driven on the street to cruise nights and some shows. Probly 20 to 40 mile trips now and then. As far as the ex vac kit, I thought those only work with open exhaust. I can use it with an exhaust?
Click to expand...

I am locked at 34* as a starting point my box I can pull timing out when cranking and your box you can also...

Evac kit for the street..... hmmm always a sticky topic. mine works fine with full exhaust ans some don't I have a good flowing exhaust system. I have my nipples placed in tubes different.

older pics but you get the point.







 
I just took a look at my MSD. Its a 6AL, not a 6AL2. Its not programmable. I get it, run as much initial as I can where it cranks OK, then tailor the advance in the dist to give the desired total advance. I'm figuring somewhere between 35 and 40 total. I'm going to start off with 15 initial and 36 total and work from there.
I should be able to run the vents into the exhaust because I'm using 3 inch with good high flow mufflers, the main restriction is going to be in the dinky headers, so after the headers should be low pressure. Thanks to all for the input.
 
I would start at 20* initial. 36 total and all in by 2500-3000 depending on how loose your converter is.
 
Younggun is on point with getting the initial timing figured out and idle settings squared away FIRST! Everything the carb does is off the foundation you start with at idle.

I have some 10 and 14* bushings for MSD's if you want to run a curve in the distributor. Not sure a 6al2 has a start retard function in it.

IMO, with that size camshaft, you're wasting time anywhere below 20* initial.
 
http://www.ebay.com/itm/290918275546?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

http://www.summitracing.com/parts/msd-8464

To the OP Your cam specs look like the XR292R? anyways before I locked my timing out and was using the bushing and springs with the comp street roller I used I had to take out them big garage door springs that are in a stock msd dizzy.... If I remember correctly I used 1 light blue and 1 light silver spring... good luck

When I had the comp street roller cam with ported the eddy rpms I ported out a TM7 intake and it worked good was low profile and had a nice rpm range. I used a adapter and ran a 1050 dominator.
 
-Sledgehammer- said:
http://www.ebay.com/itm/290918275546?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

http://www.summitracing.com/parts/msd-8464

To the OP Your cam specs look like the XR292R? anyways before I locked my timing out and was using the bushing and springs with the comp street roller I used I had to take out them big garage door springs that are in a stock msd dizzy.... If I remember correctly I used 1 light blue and 1 light silver spring... good luck

When I had the comp street roller cam with ported the eddy rpms I ported out a TM7 intake and it worked good was low profile and had a nice rpm range. I used a adapter and ran a 1050 dominator.
Click to expand...

Yep, it is the XR292. I did change the dist springs to blue and light silver. I'm going to change the bushings to bring the dist advance down to about 15 degrees and start out with 20 initial. PR only should have sprang for a programmable box, it would be a lot easier.
 
How are you going to get the mech advance down to 15 when the lowest advance msd bushing is an 18* (black).
 
there is a member here that sells the limiter bushings to get your desired advance limits. forget his name but has a charcoal grey dart post with black wheels. he has them for half the price of the other guys.

i still say you need a 12* or 14* bushing to limit your total to 36 and initial at 22-24*. I followed CRACKEDBACK's advice and it really woke my car up.
 
FBO sells 14* MSD bushings. Problem I have is my engine kicks back with anything over 18 initial.
 
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