Re: quick question on timing
[Re: pjc360]
#1197087
03/15/12 10:29 PM
03/15/12 10:29 PM
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Joined: Apr 2005
Posts: 12,271 Overpriced Housing Central
RobX4406
I Live Here
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I Live Here
Joined: Apr 2005
Posts: 12,271
Overpriced Housing Central
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Quote:
Ether way i wll have to shorten the distributer slots in the distributer to be able to get a higher initial wihout affecting my total timing. I was talking to a fairly knowledgable mopar guy today in person at my house and he told me i dont want to shorten the slots because that will kill my top end? he said if you want better low end power the gear down lower but dont mess with them distributer slots, he said you have a 360 magnum correct? i said ya he said set your total timing 32 degrees and let the initial land where ever it lands he said dont worry about the initial timing the totalm timing is way more important.
Yeah stick with those smart people you appear to get advice from.
How exactly if the total number, which is fully in anywhere above where it stops advancing is going to hurt top end... that's genius right there!
Total is a fine method if all you do is run at the strip with no concern for idle quality.
You got good advice here and at FABO about how to do it on your street driven car. My suggestion, pick a method and go with it. One way is better than the other and it's like a brick wall sometimes because some are still stuck in the 80's with a mopar performance chassis or engine book.
Mopar SB distributors will spin 360* if there is no interference. Something is inhibiting your ability to advance it further. If it has a vacuum can on it, could be that, usually. The wires from the pickup... could be that too.
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Re: quick question on timing
[Re: RobX4406]
#1197090
03/16/12 03:26 AM
03/16/12 03:26 AM
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Joined: Feb 2003
Posts: 21,318 Manitoba, Canada
DaytonaTurbo
Too Many Posts
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Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
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So after talking to this "knowledgeable" mopar guy I hope you now know why we questioned whether or not your dad knew how to setup the distributor when he built the engine. For reference, here's a chart with slot lengths. You have to multiply the distributor degrees x2 to get mechanical advance. Quote:
dist. degrees X 2 + initial= total
dist. degrees / slot size 6.............. .340 7............... .355 8............... .375 9............... .390 10.............. .405 11.5 ........... .420 12.............. .435 13.............. .445 14.............. .460 15.............. .475 16.............. .490 17.............. .505 18.............. .520
So if you wanted 20* of mechanical advance you'd need about a .400 slot. Add 15 initial to that and you get 35 total.
Also, when you start revving up the engine, what rpm is your total advance all in by? Total advance and the rate at which it comes in are both things you dial in when you setup a distributor.
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Re: quick question on timing
[Re: pjc360]
#1197096
03/16/12 09:59 PM
03/16/12 09:59 PM
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Joined: Apr 2005
Posts: 12,271 Overpriced Housing Central
RobX4406
I Live Here
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I Live Here
Joined: Apr 2005
Posts: 12,271
Overpriced Housing Central
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You need to identify which mopar distributor you have. Some have the mallory advance mechanism, easy to adjust, doesn't require disassmbly. The old style mopar ones require the distributor to be torn down. Look below the top plate and turn distributor shaft looking for a pair of T-15 torks head screws and a pair of small windows with a tab sticking up through it. If it has that style, it's a mallory set up. Loosen the torks heads and close the window up. You can easily whip up some keys for desired advance. There is some info here https://board.moparts.org/ubbthreads/show...amp;Search=trueOld style, weld the plates. http://www.moparmusclemagazine.com/techa...em/viewall.htmlI tend to weld the slot area closest to the shaft center. Mr gasket makes a light spring kit #927 IIRC if you want to change the curve.
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Re: quick question on timing
[Re: pjc360]
#1197099
03/17/12 04:17 AM
03/17/12 04:17 AM
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Joined: Feb 2003
Posts: 21,318 Manitoba, Canada
DaytonaTurbo
Too Many Posts
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Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
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Check out the links rob posted, and the description he gave, they will show you how to figure out which distributor you have. Quote:
so with a higher compression engine you want the mechanical advance to come in sooner or later?
Depends on a combination of cam and compression. If you have low compression ratio, you generally want the timing in earlier. If you have a higher compression engine with a big cam, you generally want the timing in earlier. If you have decent compression and a stock or mild cam, you may want it in a bit later if you're having detonation problems. If you're running crappy gas, you may want the timing in a little later.
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Re: quick question on timing
[Re: pjc360]
#1197102
03/19/12 02:30 AM
03/19/12 02:30 AM
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Joined: Mar 2008
Posts: 685 Bismarck, ND USA
cageman
mopar
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mopar
Joined: Mar 2008
Posts: 685
Bismarck, ND USA
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I set all my distributors up around 20- 25 degrees initial, any more and they start hard when warm. My old power wagon has 25 degrees intial, and 36 total. Thats 11 degrees of mechanical advance. Runs good, idles great. Plugs look great. I also dont use vacuum advance on any of my trucks, just my valiant. Make sure you mark where the rotor is facing when you take out the dist, that way you can line her up. I have a center punch mark on the block and the dist base that is where 36 is total is about, makes it easier to get it timed right, as I have had to put the dist in and out a few times till I got the slots welded right. If you really want bang for your buck, advance the cam 3 or 4 degrees on the timing chain, will lower the torque curve to a more useable rpm. If you have a timing chain with more than one key way slot it is easy, otherwise you will need the offset key ways.
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Re: quick question on timing
[Re: pjc360]
#1197104
03/19/12 09:11 PM
03/19/12 09:11 PM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
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it would simplify things for you. get your initial amt finalized then adj the torx screws to set the total then play with springs to adj how fast the curve comes in then hookup vac adv (if you are using it) & adj (A) when it's curve starts w a 3/32" allen wrench & more advanced can (B) alter how much advance is in it by (re)working the arms' travel
live every 24 hour block of time like it's your last day on earth
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