How to determine best timing...? - Page 5 - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep CJ Forum > How to determine best timing...?

FS: 2007-2013 Jeep Wrangler "HALO" Angel Eye KitFlowmaster's Force II Axle-back exhaust system for the 201FS: Wranger BRIGHT License Plate LED! Just $3! Great value

Reply
Unread 11-10-2013, 10:30 AM   #61
Matt1981CJ7
Web Wheeler
 
Matt1981CJ7's Avatar
1981 CJ7 
 
Join Date: May 2011
Location: Elbert, CO
Posts: 9,884
Quote:
Originally Posted by JeepHammer View Post
Yes, I know you are into 'Brevity', but that's just not the way you get a firm grasp on things...
Actually, it's the best way to get a "grasp" on certain things, and not get bogged down with information overload.


Quote:
Originally Posted by JeepHammer View Post
Pictures can't tell you why you use an iron core in a transformer coil instead of steel,
Or why the coil fires when power is CUT to the coil.
That stuff is something you will have to research, and I can help with that, but you will have to READ... Sometimes long and tedious explanations of WHY things work the way they do.
This is a classic example of what I'm talking about, Aaron. Thanks for making my point. None of that directly pertains to the OP's question, and is way more information then he is looking for. So why include it?

I'm not going to debate, or argue with you. For the record, I disagree with you on the mainifold vs. ported vac advance debate. I've formed my opinion thru a ton of research, and even more experimentation. I will continue to advise JF members accordingly.

Matt

Matt1981CJ7 is offline   Reply With Quote
Unread 11-10-2013, 10:37 AM   #62
JayCO
Registered User
1982 CJ7 
 
Join Date: Aug 2004
Location: Colorado Springs, CO
Posts: 90
Quote:
Originally Posted by Matt1981CJ7
Anyway, we have our different styles, and I think they actually compliment each other. Matt
Couldn't agree more! As a total noob, I love and appreciate Hammer's "definitive" posts. I'm a physicist by trade. I NEED to know how things work. I'm also a husband and dad of two little ones... Those three other people in my life afford me very little time to work on the CJ. Let alone toiling away to figure things out 100% on my own. So I also appreciate (need) the "here's exactly how you do it" posts. For me, the best way to learn is to see another nearby skilled Jeeper/mechanic in action <cough>Matt<\cough>... That would be the best use of the precious little time I have (given by the wife)

Cheers,
Jay
JayCO is offline   Reply With Quote
Unread 11-10-2013, 10:40 AM   #63
Matt1981CJ7
Web Wheeler
 
Matt1981CJ7's Avatar
1981 CJ7 
 
Join Date: May 2011
Location: Elbert, CO
Posts: 9,884
Jay,

Any time you want to get together and tune that beautiful CJ of yours, just let me know. We'll make it happen, soon.

Matt
Matt1981CJ7 is offline   Reply With Quote
Unread 11-10-2013, 10:41 AM   #64
swatson454
Mall-crawlin' Hot Rodder
 
swatson454's Avatar
1983 CJ7 
 
Join Date: May 2009
Location: Dripping Springs, TX (soon)
Posts: 4,728
Matt,

Don't you understand that you MUST have a degree in hydraulic engineering and be a metallurgist with a firm understanding of the molecular composition of cast iron before you can fully grasp the concept that a cannon ball doesn't float

I need to go away. I'm not posting in a manner that reflects my true personality.

Damn you, JeepHammer!
__________________
Live in a way that those who know you but don't know God will come to know God because they know you.
swatson454 is offline   Reply With Quote
Unread 11-10-2013, 10:54 AM   #65
JeepHammer
Running On Empty...
1973 CJ5 
 
Join Date: Aug 2007
Location: South West Indiana
Posts: 9,952
Enough with the personal attacks... Take ego out of it.
Since you didn't post up anything that PROVES your version, I have to take it with a grain of salt.

I don't expect anyone to take my word for it, that's why I post up references from places like Florida University, ect. when something is in question.

OK, just answer the original question...
It's not that hard.
JeepHammer is offline   Reply With Quote
Unread 11-10-2013, 11:34 AM   #66
2Xtreme
Registered User
1979 CJ7 
 
Join Date: Dec 2003
Location: Schenectady, NY
Posts: 1,191
Quote:
Originally Posted by 2Xtreme View Post
I hope to get to the garage today, so we'll see....
.................... off to the garage.
2Xtreme is offline   Reply With Quote
Unread 11-10-2013, 11:51 AM   #67
JeepHammer
Running On Empty...
1973 CJ5 
 
Join Date: Aug 2007
Location: South West Indiana
Posts: 9,952
Quote:
Originally Posted by swatson454 View Post
Matt,

Don't you understand that you MUST have a degree in hydraulic engineering and be a metallurgist with a firm understanding of the molecular composition of cast iron before you can fully grasp the concept that a cannon ball doesn't float

I need to go away. I'm not posting in a manner that reflects my true personality.

Damn you, JeepHammer!


That might be applicable or relevant if we were talking about cannon balls.
And the answer is DISPLACEMENT,
I don't know why you assume cannon balls are all made of cast iron...
That wouldn't be very 'Knowledgable' of you.

Funny thing, I just had a very polite conversation about cannon balls last night, but it was with rational, thinking historical/scientific types. (not faceless internet avatars)
Mythbusters covered cannon balls, and so did another Science channel show, so that's what precipitated the conversation.

Another diversion.

Since we WERE talking about ignition timing, where to get it, how much to get, and what 'Initial', 'Centrifugal' & 'Vacuum' came from and what they were for, it thought it was 'Relevant'.

Now, for that one simple question to be answered. Can't be this hard since I already outlined what it was for and what it did...
Unless a little reading scared people off!
JeepHammer is offline   Reply With Quote
Unread 11-10-2013, 12:05 PM   #68
ScroungerLee
Senior Member
1986 CJ7 
 
Join Date: Sep 2013
Location: Ridgefield, CT
Posts: 520
To answer JeepHammer: you are saying the initial timing is for starting the engine, right? I would agree with that. But doesn't the initial timing also affect the timing when the engine is running? For an extreme example, suppose you started with 30 degrees static advance (pretend it would run that way please) would not the centrifugal advance at any RPM where the centrifugal advance was active be way too high because of the distributor position? I think that's all Matt was saying, that the timing curves are all offset by the initial timing.

I really think both your posts were right in that respect. I really really hope this post doesn't contribute to any controversy.
ScroungerLee is offline   Reply With Quote
Unread 11-10-2013, 12:38 PM   #69
JeepHammer
Running On Empty...
1973 CJ5 
 
Join Date: Aug 2007
Location: South West Indiana
Posts: 9,952
Quote:
Originally Posted by ScroungerLee View Post
To answer JeepHammer: you are saying the initial timing is for starting the engine, right? I would agree with that. But doesn't the initial timing also affect the timing when the engine is running? For an extreme example, suppose you started with 30 degrees static advance (pretend it would run that way please) would not the centrifugal advance at any RPM where the centrifugal advance was active be way too high because of the distributor position? I think that's all Matt was saying, that the timing curves are all offset by the initial timing.

I really think both your posts were right in that respect. I really really hope this post doesn't contribute to any controversy.
No controversy in this camp.
You can't just tell someone to twist in double or triple the Initial without considering the ramifications to the rest of the advance curve.

No matter what Shawn wants to post, it's obvious he doesn't want to discuss each part of that advance curve, and what it does.

If you REALLY want answers FROM ME, about this subject, simply start a thread with the topic and 'JeepHammer' in the title so there is no confusion.
I'll try to tell you what I've found out about all these different components of the ignition curve I've leaned over the past 50+ years.

If someone wants to disagree, that's fine, but bring some explanations and examples of why they don't agree, and not just attitude and 'Because I Said So'...
JeepHammer is offline   Reply With Quote
Unread 11-10-2013, 12:49 PM   #70
Matt1981CJ7
Web Wheeler
 
Matt1981CJ7's Avatar
1981 CJ7 
 
Join Date: May 2011
Location: Elbert, CO
Posts: 9,884
Lee,

Thanks. I'll try to clarify my very original response, since it has gotten lost in the ego-fest.

The reason for being more concerned about total timing at higher RPM ranges, than initial, is because that's were your peak power and torque demands are. It's also where you will most likely suffer detonation if you have too much advance.

Because the distributers for these old tractor engines only came with a maximum of about 20* of centrifugal, by setting the total to 30*-35* at 3000 RPM, the initial should land in the 10-12 range, which runs great at mid to high elevations. If you're at sea level, I would err to the low-side of that range. Perhaps around 8* initial.

Many will find their distributers won't even advance to the 30-35* range at 3000 RPM. That's because they are hampered by an emissions distributer that only has about 8* of centrifugal. In those cases, there are ways to modify the advance head, if the owner has the inclination, or they can buy a dizzy with more advance.

I hope that helps,

Matt
Matt1981CJ7 is offline   Reply With Quote
Unread 11-10-2013, 01:05 PM   #71
ScroungerLee
Senior Member
1986 CJ7 
 
Join Date: Sep 2013
Location: Ridgefield, CT
Posts: 520
Quote:
Originally Posted by Matt1981CJ7 View Post
Lee,

Thanks. I'll try to clarify my very original response, since it has gotten lost in the ego-fest.

The reason for being more concerned about total timing at higher RPM ranges, than initial, is because that's were your peak power and torque demands are. It's also where you will most likely suffer detonation if you have too much advance.

Because the distributers for these old tractor engines only came with a maximum of about 20* of centrifugal, by setting the total to 30*-35* at 3000 RPM, the initial should land in the 10-12 range, which runs great at mid to high elevations. If you're at sea level, I would err to the low-side of that range. Perhaps around 8* initial.

Many will find their distributers won't even advance to the 30-35* range at 3000 RPM. That's because they are hampered by an emissions distributer that only has about 8* of centrifugal. In those case, there are ways to modify the advance head, if the owner has the inclination, or they can buy a dizzy with more advance.

I hope that helps,

Matt
I agree, that has always been my understanding. You stated more eloquently than I what I was trying to say.
ScroungerLee is offline   Reply With Quote
Unread 11-10-2013, 01:05 PM   #72
2Xtreme
Registered User
1979 CJ7 
 
Join Date: Dec 2003
Location: Schenectady, NY
Posts: 1,191
Set timing to 31* @ 3000 rpm
Landed at 17.7* @ 700 rpm
2Xtreme is offline   Reply With Quote
Unread 11-10-2013, 01:08 PM   #73
ScroungerLee
Senior Member
1986 CJ7 
 
Join Date: Sep 2013
Location: Ridgefield, CT
Posts: 520
Quote:
Originally Posted by 2Xtreme View Post
Set timing to 31* @ 3000 rpm
Landed at 17.7* @ 700 rpm
With or without the vacuum advance? Hopefully with it
ScroungerLee is offline   Reply With Quote
Unread 11-10-2013, 01:15 PM   #74
swatson454
Mall-crawlin' Hot Rodder
 
swatson454's Avatar
1983 CJ7 
 
Join Date: May 2009
Location: Dripping Springs, TX (soon)
Posts: 4,728
Quote:
Originally Posted by 2Xtreme View Post
Set timing to 31* @ 3000 rpm
Landed at 17.7* @ 700 rpm
Oof! That's a big problem. You now need to find out what advance head is currently installed, along with the springs. Sounds like a 12* head.

An 18* advance head will allow your initial timing to drop back down to an acceptable level.

This kind of stuff can be a PITA but it's usually worth the effort. Matt's your man on this deal


Shawn
__________________
Live in a way that those who know you but don't know God will come to know God because they know you.
swatson454 is offline   Reply With Quote
Unread 11-10-2013, 01:20 PM   #75
2Xtreme
Registered User
1979 CJ7 
 
Join Date: Dec 2003
Location: Schenectady, NY
Posts: 1,191
Quote:
Originally Posted by swatson454 View Post
Oof! That's a big problem.
Shawn
PERFECT!
2Xtreme is offline   Reply With Quote
Reply
Thread Tools






Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.