2.3L Stroker Dyno Results and Power Discussion

[revolve40]

Is there any harm to running a resistor-less rotor with a Bosch red coil, resistor-less wires, and resistor-less plugs?

['76mintgrün'02]

10 hours ago, Dudeland said:

This is what happens if you have the wrong rotor.  This was a result of a MSD 6a, and a resistor rotor (kinda high rpm) 

 

Is this the same rotor that "came loose... a lot" ?  Did it make contact with the cap when that happened?

 

 

[Dudeland]

10 minutes ago, '76mintgrün'02 said:

 

Is this the same rotor that "came loose... a lot" ?  Did it make contact with the cap when that happened?

 

 

 

Yes it did contact cap when it came off, it looked identical to the cap in question. 

 

No this is not the rotor that kept coming loose a lot, I kept replacing the cap and rotor a lot until I figured out 5 things

 

1) Don't use MSD 6a with resistor rotor.

 

2) Drill 2-3 1/4" holes in the cap, or you get condensation inside it and it corrodes the electrodes. (Tip from someone else, and part of the MSD install manual (I don't need no stinking manual!!  ).  This applies only to CD ignition applications.  It is due to the rotor heating up.  The next time you start it you will get arcing and misfires as a result of the corrosion and condensation.  Once I did this, I no longer needed to clean my rotor and cap every 2-3 weeks. 

 

3) The 123 that I have didn't hold onto the rotor as good as the stock one.  I tried bending the spring holding it. But a small dab of gasket silicone did the trick.

 

4) The springs holding the cap on my 123 aren't as robust as stock ones,  this causes the cap to shift a bit when running.  You can tell how much it moves by taking a look at the bottom inside of the cap where it touches the 123.   Bend the springs to tension them a lot, and it fixes it for the most part.  

 

5) Secure the wires well so it doesn't pull the cap to one side.  I suspect that this would cause the cap to lift or shift under heavy vibration/acceleration, especially if the motor mounts are tired.   Give yourself some slack when connecting the wire for the coil. I used a universal SBC wire loom.  (Old header there) 

 

Hope this helps someone.  

 

 

Hope this helps someone. 

 

 

 

 

[Simeon]

7 hours ago, revolve40 said:

Is there any harm to running a resistor-less rotor with a Bosch red coil, resistor-less wires, and resistor-less plugs?

 

Not unless you or your neighbors enjoy radio or television?

 

when you say ‘resistor-less’ wires, are you talking sold copper core wire or do you just mean ordinary carbon plug wires which are inherently resistors?

 

 A decent set of modern plug wires used with resistor-less plugs and even a rotor will be fine. 

[revolve40]

6 minutes ago, Simeon said:

 

Not unless you or your neighbors enjoy radio or television?

 

when you say ‘resistor-less’ wires, are you talking sold copper core wire or do you just mean ordinary carbon plug wires which are inherently resistors?

 

 A decent set of modern plug wires used with resistor-less plugs and even a rotor will be fine. 

 

Just 8mm MSD wires. Thanks for the reply - going to try the resistor-less rotor and see what, if anything, changes. Also swapping the mains tonight, and a follow up dyno run on Saturday.

Edited June 20, 2019 by revolve40

[revolve40]

So the 155 mains have leaned out WOT a touch (maybe enough), but idle leaned out as well (to the point it was spitting a little when cold). I wasn’t expecting that. Motor is still shaking a lot, but maybe normal for the 304? Maybe descync’d? Maybe needs more initial timing? So many variables!

 

02C1CB6E-FDC9-4CD0-A233-E12CE3F5E431.MOV

Edited June 21, 2019 by revolve40

[Chris_B]

You might want to try fattening up the main/air jet a bit. That tends to lean out the top end. You already have a fat idle jet. What was your AFR at idle?  Motor shaking is the classic symptom of unbalanced carbs.

[revolve40]

22 minutes ago, Chris_B said:

You might want to try fattening up the main/air jet a bit. That tends to lean out the top end. You already have a fat idle jet. What was your AFR at idle?  Motor shaking is the classic symptom of unbalanced carbs.

 

Hovering in the 13’s at idle after it warms up. And do you mean a larger air corrector? Can do, but I really don’t have an issue with a fatter top end, it’s just consistently fat on the main circuit. The 155’s (from 165’s) helped a bit, but may be able to go lower.

Edited June 21, 2019 by revolve40

[wagoner]

36mm chokes is pretty small for a 2.3L with a 304 cam.

It wants to breathe, I think pulling some fuel out (11:1 AFR is turbo charged territory) combined with 38mm chokes will help a lot. 

I'm running 45's with 36's on my 2L with 10.5:1 compression, ported short turns, 4-2-1 headers and schrick 292 and 123ign. Goes on the rollers next week. 

[Chris_B]

24 minutes ago, revolve40 said:

 

Hovering in the 13’s at idle after it warms up. And do you mean a larger air corrector? Can do, but I really don’t have an issue with a fatter top end, it’s just consistently fat on the main circuit. The 155’s (from 165’s) helped a bit, but may be able to go lower. 

Sorry, what I meant by "fattening up" is "larger" and I did mean larger air correctors. This might lean out your top end. Going to 38mm chokes will likely help in leaning out your upper RPM ranges, but may also soften up the lower RPM response. So, WRT your idle AFR, open up your idle mixture screws a bit so that you are in the high 12s.. That may help with your "spitting" problem. However, it is hard to understand how going to a larger main jet could have any effect on that. Conventional wisdom (which I have no proof of) says that 10 degrees timing is a good place to start at ~1000 RPM idle.

[revolve40]

9 hours ago, Chris_B said:

Sorry, what I meant by "fattening up" is "larger" and I did mean larger air correctors. This might lean out your top end. Going to 38mm chokes will likely help in leaning out your upper RPM ranges, but may also soften up the lower RPM response. So, WRT your idle AFR, open up your idle mixture screws a bit so that you are in the high 12s.. That may help with your "spitting" problem. However, it is hard to understand how going to a larger main jet could have any effect on that. Conventional wisdom (which I have no proof of) says that 10 degrees timing is a good place to start at ~1000 RPM idle.

 

Thanks. I'm around 10-12* at idle with a timing light. I've been told to give it as much as 16*.

 

There's probably a degree or two of static timing that I wasn't originally aware of, meaning all in I'm closer to 38*.

 

I'm going to check for sync and exhaust leaks, as well as adjust idle mixture tonight to see how it runs. May put off the follow up dyno until I have a handful of mains and airs (maybe the larger 38 mm venturis) to play with while I'm there.

Edited June 21, 2019 by revolve40

[Chris_B]

On 6/19/2019 at 4:38 PM, revolve40 said:

 

Measured the resistance tonight - it is a resistor rotor. Any thoughts as to whether or not this could be a source of high-rpm misfiring? Likely some other gremlin, but a thought nonetheless...

 

 

[Chris_B]

On 6/19/2019 at 9:27 PM, Dudeland said:

This is what happens if you have the wrong rotor.  This was a result of a MSD 6a, and a resistor rotor (kinda high rpm) 

 

 

So, it turns out that the rotor from my 123 dizzy is indeed a resistor rotor. I have been using the same type of rotor in my Bosch dizzy with my MSD 6a ignition for the last 10 years and never had anything like this happen.

[Dudeland]

3 hours ago, Chris_B said:

 

So, it turns out that the rotor from my 123 dizzy is indeed a resistor rotor. I have been using the same type of rotor in my Bosch dizzy with my MSD 6a ignition for the last 10 years and never had anything like this happen.

I am fascinated, but not surprised that this day would come.  So these my pre-determined questions to figure this out. 

 

1) What kind of coil?  Specificity is better here

2) What are your plugs? @ what gap. 

3) What are the resistance of your plug wires?   ( I expect that yours may be different) 

 

 

Edited June 23, 2019 by Dudeland

[Chris_B]

13 hours ago, Dudeland said:

I am fascinated, but not surprised that this day would come.  So these my pre-determined questions to figure this out. 

 

1) What kind of coil?  Specificity is better here

 

Jacobs; don't know the model (decal worn off the coil). Now using MSD Blaster 2

 

13 hours ago, Dudeland said:

2) What are your plugs? @ what gap. 

 

Bosch copper. Usually run about .45 gap

 

13 hours ago, Dudeland said:

3) What are the resistance of your plug wires?   ( I expect that yours may be different) 

 

Magnecor 8.5mm, 72 ohm per cm