Ignition Timing Mechanical Advance

[Zed Head]

11 minutes ago, jonbill said:

Maybe in theory one could start adding more advance again after the the torque/VE peak is passed, but that's would be very hard with springs and weights!

I wonder how many tuners are going with a flat curve because they're mimicking the limitations of the mechanical distributors.

Example from the internet - 

https://stinger-performance.proboards.com/thread/1003/megasquirt-tuning-basics-timing

Edited March 14, 2020 by Zed Head

[Captain Obvious]

17 hours ago, AK260 said:

we need one of these ....

Yes we do. That would be quite cool.

And thanks for the info links as well. I dug into the one from ls1tech and it led me to another one on that same forum which led me to another good one. Here's what I found:

https://ls1tech.com/forums/advanced-engineering-tech/254868-ignition-timing-101-a-4.html

and the original article it was based on:
http://www.contactmagazine.com/Issue54/EngineBasics.html

 

[Captain Obvious]

6 hours ago, jonbill said:

It comes from Tuner Studio (I'm a tuner too, u get me bro?)

In a stock engine I guess the action starts around 2500, so I think the rising VE and likelihood of knocking is probably why the ignition curve stays flat.

Maybe in theory one could start adding more advance again after the the torque/VE peak is passed, but that's would be very hard with springs and weights!

I get you bro.     !!

And I agree with your assessment about the rising VE. And also agree that would be very difficult with springs and weights.

Maybe I could whip up some little programmable device to try that. With the state of world events, I guess I have the time to work on projects at home...

[AK260]

Most welcome CO. Those are brilliant links / read you found - my hours of insomnia can be quite informative going through that. (It’s 04:15 here [emoji15])

Re. The state of the world as is, I don’t think I’ve done this much intensive work on the house as I have been of late. Even been fixing the roof in between monsoon like showers. My wife is also on indefinite working from home and the school just wrote to say they may close physically and go google classroom next week. Quarantined with the kids!? Arrrrrghhhhh!



Next job is to get the ignition timing right on the Z ;). If only!!

Back on topic, it’s interesting that some of those guys are taking timing away as the curve flattens. I was always told 1 degree extra per 1000 rpm after the curve goes flat. Will have to try the taking away timing thing on the next RR session.

[Captain Obvious]

9 hours ago, AK260 said:

Next job is to get the ignition timing right on the Z ;). If only!!

Right.

Her - "Hey, honey... The zombie apocalypse is coming. What should we do?"

Me - "Well I don't know what you're gonna do, but I'm gonna stay home and work on my Z."

[AK260]

Right.
Her - "Hey, honey... The zombie apocalypse is coming. What should we do?"
Me - "Well I don't know what you're gonna do, but I'm gonna stay home and work on my Z."
[emoji185]

ROFLMAO - STC!!

Funny you should say that, I’m about to turn this ....



Into one of these ....

[Captain Obvious]

Cool. Just make sure you're careful if there's any fluorocarbon (for example... Viton) in there. Don't get it too hot.

[Captain Obvious]

@AK260, So a little bit ago, you suggested that the optimum crank position for peak pressure was 22 degrees ATDC, but the articles we've bantered around suggest that 14 degrees ATDC is optimum.

Do you know the origin of your 22 degree suggestion?

[AK260]

I think it was JonBills that said 22 degrees first in this threat - I merely echoed. I blame Jon :p

 

But you are right most articles say 14. Having said that I have read 22 degrees somewhere else’s also! [emoji848]

 

[AK260]

.

[Captain Obvious]

7 minutes ago, AK260 said:

I think it was JonBills that said 22 degrees first in this threat - I merely echoed. I blame Jon :p

OK. Then I blame Jon as well. Works for me.  

[jonbill]

Yes, it was me. I think I did caveat it at the time. Back then it didn't seem important to get the detail right :)