Dissapointing performance

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AJ/FormS said:
Cam was "degreed in right", and was offered in post #1
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Yes, I read that he said that, but did he know how to do it right or did he just set it up at 110 degrees? I was just asking him to double check this AJ. That's all. I've seen some pretty funky things when guys were "following the instructions carefully"!
 
All in by 2500 is for race cars that have big TCs, and two modes of operation; namely idle and WOT.And they don't run vacuum advance.
A streeter has to satisfy a bazzilion different operating parameters, not the least of which is a whole lotta time spent at under 3500 rpm. What is the point of sacrificing driveability below 3500 in the name of "I gotta race Distributor", or some such story. If you don't have a 3500Plus TC than you can't have all in before 3500, plain and simple. Well you can but it totally messes up part throttle, and economy.
See at part throttle and steady state, and lower rpms (sub 3500 say), the engine could be wanting 30 or 40 or occasionally 50 degrees of timing. But as soon as the throttle begins to tip in some of that has to drop out. And the faster you tip it in, or the heavier the loading, the quicker it has to drop out. So if your centrifugal timing is already walking a thin line to detonation, the trickier it will be to to satisfy the cruise and PT requirements.
Since you rarely ask for full power below 3500, and a 340/360 usually has more than enough cubes to spin-up street-tires even several degrees short of optimum timing,it seems to me somewhat foolish to completely throw away the tune in this most used area.
So as a compromise,recurve your dizzy to provide 34* at 3400, and idle timing of 12 to 14. Then install the biggest Vcan you can get (I have found none bigger than 22*). And start tuning that bad boy. The max timing can be controlled by shimming the arm. The rate of advance can be controlled by the little screw inside the hose-nipple.Then when you think you got it all dialed in pretty good; add 2* more initial, to get 36* at 3400, and start over.....And when you get that working, recurve it again to get 36* at 3200 or 3000 if you are feeling lucky....
As the engine starts to get the right PT timing it will be possible to start leaning out the low-speed circuits.
This is the road to fuel economy, cool running, and a torquey bottom end;free from detonation.
But while all this is going on, the engine running temperature has to be stable. If the temp is dancing around it will be impossible to work something out. Impossible. So if your carb is still sucking hot underhood air, don't even bother beginning a tune. You are just cooking the fuel, and cooking the air. And the inlet air temp will be all over the place. And the air-density will be dancing worse.
 
GTXman
I hear what you are saying, and I agree. But I cut him some slack, at least until we run out of hiway. Besides which, my experience with the 292/508, says 4* either way, made very little low-speed difference;on the street. I would like to say extremely little, but that would be extreme.lol.
Now, I can tell you a story about a jumped chain on a teener, that the only way it would run was to retime the dizzy, and hold the 2bbl wot. And I think it mightof reved to 500rpm! I did the retiming while sitting under the hood and yanking on the dizzy until it started to fire. I was about 23, and had been working on cars for 8years, so I knew absolutely everything about sbms,lol. So I thought anyway.......
 
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AJ/FormS said:
All in by 2500 is for race cars that have big TCs, and two modes of operation; namely idle and WOT.And they don't run vacuum advance.
A streeter has to satisfy a bazzilion different operating parameters, not the least of which is a whole lotta time spent at under 3500 rpm. What is the point of sacrificing driveability below 3500 in the name of "I gotta race Distributor", or some such story. If you don't have a 3500Plus TC than you can't have all in before 3500, plain and simple. Well you can but it totally messes up part throttle, and economy.
See at part throttle and steady state, and lower rpms (sub 3500 say), the engine could be wanting 30 or 40 or occasionally 50 degrees of timing. But as soon as the throttle begins to tip in some of that has to drop out. And the faster you tip it in, or the heavier the loading, the quicker it has to drop out. So if your centrifugal timing is already walking a thin line to detonation, the trickier it will be to to satisfy the cruise and PT requirements.
Since you rarely ask for full power below 3500, and a 340/360 usually has more than enough cubes to spin-up street-tires even several degrees short of optimum timing,it seems to me somewhat foolish to completely throw away the tune in this most used area.
So as a compromise,recurve your dizzy to provide 34* at 3400, and idle timing of 12 to 14. Then install the biggest Vcan you can get (I have found none bigger than 22*). And start tuning that bad boy. The max timing can be controlled by shimming the arm. The rate of advance can be controlled by the little screw inside the hose-nipple.Then when you think you got it all dialed in pretty good; add 2* more initial, to get 36* at 3400, and start over.....And when you get that working, recurve it again to get 36* at 3200 or 3000 if you are feeling lucky....
As the engine starts to get the right PT timing it will be possible to start leaning out the low-speed circuits.
This is the road to fuel economy, cool running, and a torquey bottom end;free from detonation.
But while all this is going on, the engine running temperature has to be stable. If the temp is dancing around it will be impossible to work something out. Impossible. So if your carb is still sucking hot underhood air, don't even bother beginning a tune. You are just cooking the fuel, and cooking the air. And the inlet air temp will be all over the place. And the air-density will be dancing worse.
Click to expand...

you wouldn't happen to have a part number for that vacuum can would you?
 
No, sorry. If I did you bet I would have included it. I shopped the jobber catalog for over a half hour to find it. That was over 15 years ago.
You can build your own by cutting away the stops on the backside, but it is very tricky. There was a fellow on FABO,last winter who did that, but I forget his name. Maybe Jim or Jimmy or bludream, IDK.
 
Should have bought this at mopars in the park.
1469152563_zpsatiad1k0.png
 
Oh I know I have been looking for a while. Most people that have them are down right proud of them things.
 
68gtxman said:
Yes, I read that he said that, but did he know how to do it right or did he just set it up at 110 degrees? I was just asking him to double check this AJ. That's all. I've seen some pretty funky things when guys were "following the instructions carefully"!
Click to expand...
That cam has 4 degrees advance "build in" so I quess I set it to 106. I dont have cam card right here to check what it was.
 
AJ/FormS said:
All in by 2500 is for race cars that have big TCs, and two modes of operation; namely idle and WOT.And they don't run vacuum advance.
A streeter has to satisfy a bazzilion different operating parameters, not the least of which is a whole lotta time spent at under 3500 rpm. What is the point of sacrificing driveability below 3500 in the name of "I gotta race Distributor", or some such story. If you don't have a 3500Plus TC than you can't have all in before 3500, plain and simple. Well you can but it totally messes up part throttle, and economy.
See at part throttle and steady state, and lower rpms (sub 3500 say), the engine could be wanting 30 or 40 or occasionally 50 degrees of timing. But as soon as the throttle begins to tip in some of that has to drop out. And the faster you tip it in, or the heavier the loading, the quicker it has to drop out. So if your centrifugal timing is already walking a thin line to detonation, the trickier it will be to to satisfy the cruise and PT requirements.
Since you rarely ask for full power below 3500, and a 340/360 usually has more than enough cubes to spin-up street-tires even several degrees short of optimum timing,it seems to me somewhat foolish to completely throw away the tune in this most used area.
So as a compromise,recurve your dizzy to provide 34* at 3400, and idle timing of 12 to 14. Then install the biggest Vcan you can get (I have found none bigger than 22*). And start tuning that bad boy. The max timing can be controlled by shimming the arm. The rate of advance can be controlled by the little screw inside the hose-nipple.Then when you think you got it all dialed in pretty good; add 2* more initial, to get 36* at 3400, and start over.....And when you get that working, recurve it again to get 36* at 3200 or 3000 if you are feeling lucky....
As the engine starts to get the right PT timing it will be possible to start leaning out the low-speed circuits.
This is the road to fuel economy, cool running, and a torquey bottom end;free from detonation.
But while all this is going on, the engine running temperature has to be stable. If the temp is dancing around it will be impossible to work something out. Impossible. So if your carb is still sucking hot underhood air, don't even bother beginning a tune. You are just cooking the fuel, and cooking the air. And the inlet air temp will be all over the place. And the air-density will be dancing worse.
Click to expand...
Good article you wrote. How ever I dont agree that I should put mechanical timin all in that far 3400 rpm. Earlier I had this engine with smaller cam (268) and old heads (596 ported) then I removed the stiffer spring from stock distributor to get all mechanical advance in at about 2000 rpm. Car got alot more torque at low rpm (in WOT) Is the magnum type heads so different that it needs all in at 3400? I could use small decree vacuum canister that doesnt give too much advance in steady part thorttle.
 
Someone asked about that I might have fuel problem. I have almost new Holley red fuel pump and 3/8 lines from tank to carb hose. I made new fitting to tank that is 3/8"
And yes I have vacuum gauge.
 
After checking more carefully my full advance comes in at 1600 rpm. That explains why this car want low idle timing. I need to find springs that gives me full advance at least 2200.

That distributor machine would be handy.
 
Dusterguy said:
That cam has 4 degrees advance "build in" so I quess I set it to 106. I dont have cam card right here to check what it was.
Click to expand...

You also said somewhere in this thread that the chain had a fair amount of slack. You might have lost those 4 degrees and the cam timing is in a retarded position.
 
GeorgeH said:
You also said somewhere in this thread that the chain had a fair amount of slack. You might have lost those 4 degrees and the cam timing is in a retarded position.
Click to expand...
I just did compression test on hot engine and I got 170 psi.
 
The dizzy tester I scored is fully functional, but I haven't had a use for it yet. After seeing what they're going for, I've considered selling it.
 
Dusterguy said:
3.23 rear end ratio
904 lockup trans and 2200 stall speed custom converter. I havent found bigger stall speed converter here where I live.
14 inch wheels not so tall tires 205/50
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I have a 4200 Stall for sale for a 904
 
Dusterguy said:
Good article you wrote. How ever I dont agree that I should put mechanical timin all in that far 3400 rpm. Earlier I had this engine with smaller cam (268) and old heads (596 ported) then I removed the stiffer spring from stock distributor to get all mechanical advance in at about 2000 rpm. Car got alot more torque at low rpm (in WOT) Is the magnum type heads so different that it needs all in at 3400? I could use small decree vacuum canister that doesnt give too much advance in steady part thorttle.
Click to expand...
Well, Ima gonna pull a Rusty on you; I don't really care if you agree with me or not.
You are gonna spend dozens of hours fighting your rebellion, and in the end you will either slow down the centrifugal,or disconnect the can, or severely limit it's function. And I'm ok with that for two reasons;1) I'm not paying you to learn on my car, and 2)that's how I learned too.
I am just trying to save you two or three summers of learning.
Now my question to you is did you read all of the article?
 
AJ/FormS said:
Well, Ima gonna pull a Rusty on you; I don't really care if you agree with me or not.
You are gonna spend dozens of hours fighting your rebellion, and in the end you will either slow down the centrifugal,or disconnect the can, or severely limit it's function. And I'm ok with that for two reasons;1) I'm not paying you to learn on my car, and 2)that's how I learned too.
I am just trying to save you two or three summers of learning.
Now my question to you is did you read all of the article?
Click to expand...

You can only lead them to the water.
 
AJ/FormS said:
Well, Ima gonna pull a Rusty on you; I don't really care if you agree with me or not.
You are gonna spend dozens of hours fighting your rebellion, and in the end you will either slow down the centrifugal,or disconnect the can, or severely limit it's function. And I'm ok with that for two reasons;1) I'm not paying you to learn on my car, and 2)that's how I learned too.
I am just trying to save you two or three summers of learning.
Now my question to you is did you read all of the article?
Click to expand...
Looks like your ego is so big that no one can disagree with you.

I made question for you, can you answer that or not.
 
Dusterguy, 3400 is a good starting point for you mechanical advance. That is not set in stone. After your carb and exhaust are upgraded where they're not strangling the motor, that is when the tuning really begins. 3400 would be a good starting point, after that you can adjust to the needs of your motor. Every combo is different. However calling someone on ego is non productive as everyone has tried in their own way to offer advice. Take it with a grain of salt my friend.
 
I think AJ was the dick now. "I dont reallly care if you agree with me" what talk is that..

I have talked some expert who have build Mopar engines 30 years here and he said: put all mechanical advance about 2200-2400rpm. That is advice what I have been listened. And that was what I did before and it worked. Now if someone says it need it to be 3400 rpm then I want to hear why.

I dont claim to be one that knows everything. Im here to learn and listen other people opinions.
 
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