Re: 440 Power Timing, cant get above 2350 rpm in park
[Re: Digger73]
#2074445
05/16/16 12:26 PM
05/16/16 12:26 PM
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Joined: Jan 2003
Posts: 75,282 A gulag near you.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,282
A gulag near you.
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Hi all, I was trying to follow the instructions from the dodgetravcos site and set timing 0n my 440 to 38 BTDC at 2600-2800 rpm. I just cant get there. I have a 440 with a Comp Cams 280H cam and a Street Demon carb (the newer Thermoquad/Quadrajet hybrid style) When I turn the idle set screw all the way down I only get 2350 rpm. Car seems to run fine, has good power. What am I doing wrong? Is something limiting the idle mixture screw at idle in Park? can I just set 38BTDC at 2350 RPM. Any help or advice would be greatly appreciated. Thanks Vic Do any of you guys ever read what the original questions? He is trying to get the curb idle screw to run the engine up to 2800 rpms. To answer your question. Manually move the throttle by hand to the 2800 rpms. Then adjust the timing to where you want it. Digger73 (Mike) Few do ... If his distributor is stock and never been recurved he is not going to be able to get his initial up to 16 plus degrees and not have his total mechanical below 45 ... Stock distributors usually have 30 degrees of mechanical advance built into them. I'm not even sure he has said what distributor he has ??
Mainstream Media is the new Pravda
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Re: 440 Power Timing, cant get above 2350 rpm in park
[Re: brando]
#2074520
05/16/16 02:18 PM
05/16/16 02:18 PM
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Joined: Jan 2003
Posts: 75,282 A gulag near you.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,282
A gulag near you.
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I have a stock distributor, but I have no idea what the previous owners did to it in the past. I'm tearing into it now. That's the first place to start , without that knowledge you , or anyone else , can't possibly know what to do . Is it points or electronic ?
Mainstream Media is the new Pravda
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Re: 440 Power Timing, cant get above 2350 rpm in park
[Re: JohnRR]
#2074545
05/16/16 02:53 PM
05/16/16 02:53 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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With some long thin needle nose pliers you can spread the clip enough so you can lift it out with out mangling it (might take (6) "spreading" attempts to get it wider than the nub tho I've spread it some then grabbed a vertical leg & ripped it around to the open side & up in one motion & reused em many times. OE would be a light spring and a heavy spring with an elongated loop on one end and the plate will have a number on it (underneath) for the amt of (dist) adv it has (the slot length(s). I would highly suggest ordering the FBO plate/springs which I believe you already have as it is a must have. We have the initial finalized & the plate will set the total then we can move on to the springs then on to the can. One caveat, the slot plate always want to come up off of the weight nubs which is a real pain if the (2) thin round base plates are in place so ANYTIME you are removing the reluctor up off the shaft ALWAYS press down on the top center shaft with your thumb on your free hand and when removing the rotor press on the reluctor underneath it. EDIT Yes I had ASSuMEd that it was electronic! MORE EDIT then we will address rotor tip clearance and Rotor Phasing (how could I forget that) and reduce lower shaft axial play to .005"
Last edited by RapidRobert; 05/17/16 09:21 AM.
live every 24 hour block of time like it's your last day on earth
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Re: 440 Power Timing, cant get above 2350 rpm in park
[Re: brando]
#2074703
05/16/16 08:13 PM
05/16/16 08:13 PM
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Joined: Aug 2003
Posts: 43,744 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,744
Bend,OR USA
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Most of the stock Mopar OEM distributors will have the amount of mechanical advance stamp (usually from 10 to 14 camshaft degrees(with a R or L after the numbers) which is twice as much degrees on the crankshaft ) onto the bottom of the advance plate. The advance plate is what the rotor rides on, to shorten or reduce the amount of mechanical advance you will need to shorten those slots equally. For instance if the number is 13 that means you have a maximum of 26 degrees crankshaft advance with that distributor, I measure the length of the slot and the diameter of the pins on the advance wieghts and subtract that from the slot length, the length of the remaining slot can be divided by the 26 for the amount to see how much each degree equals in thousands and shorten the slot up by the amount you want to have. For instance say the total slot length is .750 and the pin diameter is .250 so the remaining slot length is .500, divide 26 into .500 to get the amount in thousands each degree is, which on my calculator is .01923 rounded to the fourth place after the decimal point. So if I wanted to have 16 degrees mechanical advance I would shorten up the slot to be .30768 or rounded off at .307 So if you do that and set the initial timing at 16 degrees BTDC you would have 32 degrees total timing or if you set the initial at 18 BTDC you should have 34 degrees BTDC total timing. Hopefully you get the main thinking on this even though it is not dead nuts accurate on the actual measurements.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: 440 Power Timing, cant get above 2350 rpm in park
[Re: brando]
#2077068
05/20/16 12:08 PM
05/20/16 12:08 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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Vic (1) set the plate on the pair of rectangle slots that will give you 36 total (start with the 10 pair) then check total with can capped. (2) Keep the light OE spring in there & sub in the lightest one of the (3) FBO springs for a start & romp on it up thru the gears & if it pings then sub in the next heavier one & repeat. You want to be a bit under the pinging point on your hottest/driest day up thru the gears. slight pinging can be hard to hear sometimes and there is silent ping so just stay a bit under it as pinging is extremely damaging. (4) for a stable/repeatable idle you also want the springs/slots to not start advancing any lower than 100-200 RPM above your hot in drive idle speed which is what the eng will see at the stoplight (in other words so you ain't into the springs while idling. A friend has the "tuning to win" booklet & I was not impressed by it. it'd be good for a strickly 1/4 mile drag racer only imnho but I did glean a few good tidbits from it. We have the initial finalized & we're on the slots then the springs then we'll hook up the can & work with it
live every 24 hour block of time like it's your last day on earth
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Re: 440 Power Timing, cant get above 2350 rpm in park
[Re: RapidRobert]
#2077121
05/20/16 02:27 PM
05/20/16 02:27 PM
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Joined: Aug 2012
Posts: 54 USA
brando
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USA
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Re: 440 Power Timing, cant get above 2350 rpm in park
[Re: brando]
#2080433
05/26/16 12:52 AM
05/26/16 12:52 AM
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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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you have 36 with the can capped? One backfire then it pulls hard (or not)?is that a backfire in the carb or out the tailpipe(s)? is the AP giving an immediate/healthy (quantity/duration) stream immediately on tip in (you jerk the throttle & it is squirting)?
live every 24 hour block of time like it's your last day on earth
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Re: 440 Power Timing, cant get above 2350 rpm in park
[Re: brando]
#2080846
05/26/16 06:59 PM
05/26/16 06:59 PM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
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Posts: 36,041
Lincoln Nebraska
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yeah we gotta get the backfire taken first. More info on that, at what RPM /amt of throttle (part or WOT) is it doing it/just once or multiple times
live every 24 hour block of time like it's your last day on earth
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Re: 440 Power Timing, cant get above 2350 rpm in park
[Re: brando]
#2081103
05/27/16 02:40 AM
05/27/16 02:40 AM
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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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disconnect the can & retry it & see if it still pops (rotor phasing issue). the floats are set correct & you said the squirt was pretty healthy? I'm trying to decipher if it is a lean condition (which it sure sounds like) to continue further. EDIT will it rev above 2350 RPM like it was stuck at originally?
Last edited by RapidRobert; 05/27/16 02:41 AM.
live every 24 hour block of time like it's your last day on earth
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Re: 440 Power Timing, cant ghet above 2350 rpm in park
[Re: brando]
#2083963
06/01/16 11:37 AM
06/01/16 11:37 AM
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Joined: Dec 2007
Posts: 1,584 MD
p d'ro
pro stock
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pro stock
Joined: Dec 2007
Posts: 1,584
MD
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Did you set your idle mix screws to max vacuum? Take them all out 1/4 turn at a time for max vacuum then put back in 1/4 turn. Start all at 1.5 turns out. All should end up set at same number of turns out.. After setting timing do again. Correct Robert? Stop turning out idle screws to raise idle.. Where are u in MD. Our weather sucks.
Last edited by p d'ro; 06/01/16 01:20 PM.
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