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  #1  
Old 08-21-2001, 07:37 PM
moparmarc moparmarc is offline
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Question Too much advance too early? (was: Proper Base timing)

Is there such a thing as total mechanical coming in too early?

My 1974 Charger 360 used to smoke the tires in 1st and 2nd gear (TF 727) but no longer does now that I've replaced the distributor springs with lighter ones.

The total advance (32 deg.) used to come in at 4500 rpm and now comes in at 2000 rpm. Is this too early? Should I mix one light spring with one of the stock springs?

moparmarc
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Old 08-21-2001, 08:08 PM
DAVE JONES DAVE JONES is offline
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Marc, I'm not too sure which way to go here. I know that you had problems referencing your other post and I dont know if those were cleared up yet regarding the amount of advance you were running. Are those problems gone?
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Old 08-21-2001, 08:48 PM
moparmarc moparmarc is offline
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I think you have me confused with the guy who couldn't get his 318 to start at high initial timing.

My problems actually started when I noticed that I could only get 20 deg. of mechanical advance out of the distributor. I found that setting the initial timing at 12 deg. would get me 32 deg. total but that it didn't come in until 4200 rpms.

I replaced the springs and now get all advance in at 2000 rpm but the car is pinging a bit and no longer lights up the tires the way it used to.

I'm thinking that 32 deg. at this rpm is too much. Is this correct?

moparmarc
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  #4  
Old 08-21-2001, 10:05 PM
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The-Challenger The-Challenger is offline
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hey marc you are on the right track i had the same problem on my challenger.
in fact the springs were so light i had a hard time timing the motor the springs were advancing as early as 500 rpm idle
i went back to the stock lighter spring and had to buy another at the local hwd. store and tried a few diffrent combos and i got it very close i now have full advance at 2600 rpm and this seems to be about what my motor likes yours might be diffrent.
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Old 08-22-2001, 05:06 AM
DAVE JONES DAVE JONES is offline
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Sorry bout the mixup doc. I did have you confused with the other member. I'll leave my "push rod hell" baggage behind now. When I switched my spings on my dist, I also tried some that were too soft and were kicked in during idle so the timing mark was jumping around. I ended up using a combination of doner springs but my setup still liked to be fully advanced by 2000. I dont know if your engine is built or what the CR is but this also does play a major role.
I also want to mention that you may want to check a few things out first before you decide on what spings you want to end up with. Bringing in your advance earlier than 4000 should always be a performance plus but there are other things to consider and other adjustment may need to be made.
1.....Find TDC of #1 and make sure that the mark on the balancer does line up with O on the timing mark. I've seen alot of guys not check this and get phantom readings and problems with this.
2..... Is the gas you're using up to par. does your pinging go away with a 93 octain or higher?
3......What do your plugs look like. you may be running too lean.

These are just a few things to look at before you settle on what springs work the best. I'm sure others will mention some more. The RPM that Challenger's motor is working good for him and like he said......."For HIS motor". Yours may work good with this also. If it were me, I would check a few things first.
Good luck and keep us posted..........dj
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Old 08-22-2001, 11:46 AM
beepbeepsrule beepbeepsrule is offline
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I think your distributor has more than 20 degrees mechanical advance. The stiff stock spring may have been holding it back some even at 4500 rpm. Have you checked the total advance with a dial-back timing light since you put in the lighter springs? Most of the MoPar distributors I have modded with springs had more like 26 degrees mechanical. I always set them at the total I wanted which on 383's and 440's is usually 34-36 degrees. That usually gave me an initial between 8 and 10 degrees. If your distributor realy has 26 degrees mechanical then your 12 degree initial setting is giving you 38-40 degrees which is getting into full-race VP fuel territory.
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Old 08-22-2001, 12:07 PM
moparmarc moparmarc is offline
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I usually set the total advance and then check the initial setting rather than the opposite. This prevents me from gettting too much mechanical advance. If the car won't start at this point, then I start messing around with the initial timing.

Right now I have the total advance set for 32 deg, which the motor seems to like (no pinging) but doesn't pull away like the old setup did.

Keep in mind that I also replaced the stock TQ carb and cast iron intake with an edelbrock setup. The shop that dialed in the carb didn't have all the equipment working and were unable to check fuel mixture at WOT. This may be my problem. They told me they'd recheck for free once the hardware was up and running. It may be time to do this.

Thanks for all your assistance.

moparmarc
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Old 08-22-2001, 01:01 PM
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I have both lightweight springs in my super bee, and all of hte advance is in by 1,400rpm.

It runs 13.20's in street trim with this combo in a 9.5/1 compression mild 383.
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Old 08-22-2001, 02:43 PM
beepbeepsrule beepbeepsrule is offline
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moparmarc wrote:"... Keep in mind that I also replaced the stock TQ carb and cast iron intake with an edelbrock setup. The shop that dialed in the carb didn't have all the equipment working and were unable to check fuel mixture at WOT. This may be my problem. They told me they'd recheck for free once the hardware was up and running. It may be time to do this. ..."

Now we know the REST of the story!!! (Were you testing us???). Spark advance coming in from between 1400 and 1800 and all in by 2000-2100 is what a hot-rod engined car will want. By hot-rod I mean performance cam, 4 bbl, dual exhaust, lower gears, etc.
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Old 08-22-2001, 02:52 PM
moparmarc moparmarc is offline
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Right. This car, other than the Edelbrock intake and carb, is a bone stock 360 california car (single exhaust, egr disabled).

Sorry about the confusion.
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