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9/22/06 8:33am - Original Message: 'How much "Advance" is too much?'
jbova2
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350 with Edelbrock heads,cam,intake, and carb. (Performer series)
Engine runs smooth and starts easily. I have always been told to run as much advance as the engine would allow without pinging. Is more going to improve horsepower?
I've seen improvments from 10 up to 13 degrees...
 
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9/22/06 8:43am - Reply: 'How much "Advance" is too much?'
cthulhu Lifetime Member
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yes...   but just adjusting initial advance high as you can without pinging isnt enough to get the most out of it
 
you should try the vaccum adjustment method I have posted in great detail on these forums.


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9/22/06 9:21am - Reply: 'How much "Advance" is too much?'
jbova2
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Got it, Thank you...Didn't realize this subject was so greatly debated and explored here. I'll try the vacume method and then verify and report the timing light results.
 

the higher the manifold vacuum.. the "hungrier" the engine is..

Thanks Gramps.....
 


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9/26/06 11:54am - Reply: 'How much "Advance" is too much?'
cthulhu Lifetime Member
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gramps ???
 
I hope you werent referring to me..
 
im 32 !!!!LOLLOL


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9/27/06 7:44am - Reply: 'How much "Advance" is too much?'
jbova2
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No No No, I thought you said from the other related thread that you learned this way of tuning from your Gramps. I appericiate the advise and tried it out. Got H U G E Power increase over setting timing by the light. Took her out for a test ride and Wowser Go Go Gadget it was fast, But then (BUTT) It was a little weary of wanting to start, so I backed her off just enough to make it "Startable" and it runs fine. Later I found a slight stumbly miss which was corrected by resetting the Spals programable to allow a little more heat on the heads. Everything is well now, although I believe a Accel Super Coil is in the near future to ignite the new plat plugs.
 thanks again,
Jb


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9/27/06 9:40pm - Reply: 'How much "Advance" is too much?'
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Got yer money's worth already, eh, JB?

Glad ya got it runnin better. I've used "Gramp's" method too, and it absolutely werks, every time. I have to agree with Ben...timing lights are only good for seeing where it is once you get it right!!

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9/28/06 6:24am - Reply: 'How much "Advance" is too much?'
jbova2
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No Question about getting my moneys worth Joel, Best ten bones I have ever spent.
 
Thank you and all of the members for making this such a resourceful forum.
 
JB
 


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10/1/06 9:05pm - Reply: 'How much "Advance" is too much?'
jbova2
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OK, Her I go again. Can't leave well enough alone and all. LOL

I have advanced the Mallory HEI to Max vacume at idle (1000 RPM)= 16 PSI and took her out for a ride. Ran FANTASTIC,
 Would not start at all though, so I backed off the timing to 13 PSI at idle until I could fire her up. Readjusted the carb and all was well until.....

 How can I get the full power and the ability to turn the engine over too? I set the timing with a gauge with the vac advance blocked off. Can I alter the vacume advance to kick in around 2500-300 RPM? or am I missing something. Even thought maybe the starter was week (New Starter though) New Battery....Arrrrgggg. I really want it to run like it did at 16 PSI (set at idle) No Pings, No Miss, just F A S T .....Smokin Fast.... At 13 PSI It is not the same......

Thank you for your patience here. I really did look for the other thread and seem to not be able to find it.

Anyone? Ideas?
JB
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10/2/06 12:01am - Reply: 'How much "Advance" is too much?'
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Sounds like you're gonna have to do some changes to the mechanical advance, most likely a spring change. This will get you the full advance that you need to run "fantastic"(is that a scientific term?), and still be able to start when hot. The problem's gonna be determining what spring/weight set-up is gonna be the best all around.
The springs/weights on the advance mechanism work more from rpm changes; vac. advance is more closely related to engine load.
Try this...stay with me now...
Disconnect the vac. from the dist. Then adjust the timing until the car runs well, reguardless of hard starting. Then, check the timing with a light, and make note of that setting.
Now, reconnect the vac. to the dist., and set the timing(with the light) to the same setting you got from the above step. Drive again and see how it werks out. This should give you the same results as with the vac. unhooked, but it should start ok. If it doesn't run as well this way, I would think a spring change would be needed.

You also need to verify the vac. advance can will hold vac., and will move the advance plate thru it's full range, with a vac. pump. Not all advance cans will hold vac. for a long time...some are "vented", for lack of a better werd. It should still be able to move the plate, and hold it for several seconds before slowly bleeding off.

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10/2/06 5:57am - Reply: 'How much "Advance" is too much?'
jbova2
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Thanks Joel, I'll give it a shot after work today.
 
"Fanstastic" LOL The difference is "nailing it" (Another Engineering term) at dead stop with 16 PSI Manifold Vac. at 1000 RPM means smoking the new BF Goodriches and "Chirping" (another) Hard in Second. Anything less than 16 PSI at idle is night and day slower and less responsive under 4000 RPM. Highway is not an issue, nor has Pinging been experienced thus far. Do to the fact that the engine was built by and with yet unknown to me specifications, I'm feeling my way around this one in the dark so to speak.
 
Seems to want to be fully advanced around 2500 R's to run like the "Assaulted Ape". Once you feel this kind of performance, you never want less. Always More and More.....LOL
 
Thanks again, I'll certainly be back with either a positive progree report, or with more vac. can questions......
 
JB
 


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10/2/06 10:35am - Reply: 'How much "Advance" is too much?'
71Shark
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Okay - while we are talking about timing.  My engine builder (he builds drag cars)  put three marks on my harmonic balancer for timing.  He marked the line that is used to set timing and then a ways down is a mark that says 30 and further down is a mark that says 40.  What do those mean. The car runs fine but as I read this thread it sounds as though some fine tuning could be done for better performance.  Any help or ideas?

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10/2/06 11:04am - Reply: 'How much "Advance" is too much?'
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Some builders will mark the balancer to make it easier to set the timing at certain rpms. Most pro racers have the balancer marked all the way around to help with "degree-ing" the cam. Matter of fact, most pro type balancers are marked that way to start with.(Fluidamper, etc.)
For instance, if you wanted 30deg. advance @ 3000rpm, then you would simply set the engine rpm to 3000, and look at the timing mark(30deg), and set that mark(30deg) on the "zero" on the timing tab. I have an advancable timing light, and it does basically the same thing, but it uses electronics to do it. If I want 30deg @ 3000rpm, I just set the rpm, and "dial in" 30deg on the light, and then line up the "0" on the balancer. Does the same thing, with less fuss.

Another trick some engine builders will do, is mark the balancer for true TDC. This involves using a piston stop, and turning the engine by hand until it hits the stop. Mark the balancer there, and then turn the engine the other direction until it hits the stop there, and mark the balancer. The exact center distance between the two marks you just made will be "true" TDC, as seen on the balancer. Then, the balancer is marked at that center distance, to be used as TDC when timing the engine. This eliminates any balancer defects, as far as timing marks go.
Does this make any sense at all?!

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10/2/06 11:34am - Reply: 'How much "Advance" is too much?'
71Shark
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It does.  So I should check my timing at idle, 3000 and 4000 rpm to see if my vac advance is working properly.   Should these three marks all hit the same spot when timing at the set RPM?

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10/2/06 3:13pm - Reply: 'How much "Advance" is too much?'
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Well, I couldn't tell you WHY he marked the balancer like that. In theory, tho, if you wanted 30deg. advance @ 3000rpm, then the 30deg. mark would line up with the "0" on the timing tab @ 3000rpm. By "0", I mean the TDC position on the timing tab. Most of them are a large "V" shape notch, and are marked as "0".
The total advance, and what RPM it comes in at will vary according to the engine builder's preference, or what actually works best for each engine/vehicle/driver combo. There really is no one set way to do it, or one carved in stone spec. The only real way to get it done properly, for the most usable HP, is on a chassis dyno. Most of us do not have access to one o dem bad boys, so...we just play it by ear!

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10/2/06 3:26pm - Reply: 'How much "Advance" is too much?'
cthulhu Lifetime Member
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yes..  a springs change is pretty much a requirement to set the timing perfect..
 
unfortunately you can the the initial timing high where it will labor on a warm start.
 
a high torque starter can help this.
 
but the real issue isnt whether the timing is 13 or 16 at idle..
 
its the extra 3 degrees at 2500 rpm or wherever your rpms are when youre doggin it.
 
 


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10/2/06 3:32pm - Reply: 'How much "Advance" is too much?'
cthulhu Lifetime Member
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[QUOTE=Adams' Apple]Some builders will mark the balancer to make it easier to set the timing at certain rpms. Most pro racers have the balancer marked all the way around to help with "degree-ing" the cam. Matter of fact, most pro type balancers are marked that way to start with.(Fluidamper, etc.)
For instance, if you wanted 30deg. advance @ 3000rpm, then you would simply set the engine rpm to 3000, and look at the timing mark(30deg), and set that mark(30deg) on the "zero" on the timing tab. I have an advancable timing light, and it does basically the same thing, but it uses electronics to do it. If I want 30deg @ 3000rpm, I just set the rpm, and "dial in" 30deg on the light, and then line up the "0" on the balancer. Does the same thing, with less fuss.

Another trick some engine builders will do, is mark the balancer for true TDC. This involves using a piston stop, and turning the engine by hand until it hits the stop. Mark the balancer there, and then turn the engine the other direction until it hits the stop there, and mark the balancer. The exact center distance between the two marks you just made will be "true" TDC, as seen on the balancer. Then, the balancer is marked at that center distance, to be used as TDC when timing the engine. This eliminates any balancer defects, as far as timing marks go.
Does this make any sense at all?! [/QUOTE]
 
you can buy a sticker tape that goes right on the balancer to have the marks.
 
I just bought a new 8" (instead of stock 7") balancer to go on my 427 and put a tape sticker on there to help in record keeping. (note: you also need to change timing pointer when changing balancer size)
 
I keep a tuning journal when I do this.. and I generally will map the timing out from idle to peak by 250 rpm..
 
this gives you a very good mapping of where it is set..
 
that way when you have your foot to the floor going up a hill and you hear detonation..  just look to see where the tach is.
 
it is very easy to make a spring change with this info mapped out.
 
cthulhu2006-10-02 12:37:20

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10/2/06 3:33pm - Reply: 'How much "Advance" is too much?'
71Shark
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Thanks Joel!

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10/2/06 3:35pm - Reply: 'How much "Advance" is too much?'
cthulhu Lifetime Member
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69 Conv #'s Match 427, TKO-600, 3.36HD-Posi, T/T, PS, PB, PW, SP, Lthr, Comp Mag 270 & Pro Rlr Rockers, Edel Air-Gap RPM, BG SD 750 MS, MSD 6AL+Tach Dist+ Blaster SS+Wires, Hly Bl Fuel Pump, K&N, Jet-Hot Hkr Side-Pipes,Steeroids, Al Rad, Spal Fans

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[QUOTE=jbova2]OK, Her I go again. Can't leave well enough alone and all. LOL

I have advanced the Mallory HEI to Max vacume at idle (1000 RPM)= 16 PSI and took her out for a ride. Ran FANTASTIC,
 Would not start at all though, so I backed off the timing to 13 PSI at idle until I could fire her up. Readjusted the carb and all was well until.....

 How can I get the full power and the ability to turn the engine over too? I set the timing with a gauge with the vac advance blocked off. Can I alter the vacume advance to kick in around 2500-300 RPM? or am I missing something. Even thought maybe the starter was week (New Starter though) New Battery....Arrrrgggg. I really want it to run like it did at 16 PSI (set at idle) No Pings, No Miss, just F A S T .....Smokin Fast.... At 13 PSI It is not the same......

Thank you for your patience here. I really did look for the other thread and seem to not be able to find it.

Anyone? Ideas?
JB
Confused

[/QUOTE]
 
take your springs down 1 setting..  OR it may be that your limit is too low.
 
if you have a limit bushing..  make it one size smaller
 
try one at a time..  but try both as well..


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10/14/06 9:49am - Reply: 'How much "Advance" is too much?'
jbra2469
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Reading all the posts on the subject of timing the engine, I'm really confused now.
 
I have Edelbrock heads, factory aluminum intake manifold, and HEI distributor off late-model small block without vacuum advance canister.
 
Car runs terrific, but when stopped at traffic light for instance, when the idle drops way down, (automatic transmission by the way), it runs like crap.  Just about stays running, usually have to put it into neutral until the light changes, then nurse it along to keep it running until it gets off idle.
 
I'm still running the Q-Jet and have tried to find any vacuum leaks that might be causing the stumbles, but it seems like that is not the problem.  
 
Is it possible that my brake booster has gone bad, and when I'm stepping on the brake, I'm creating a vacuum leak in the booster can?
 
I've played with timing and it's now set at 14 degrees, which I set with timing light.
 
Jim  
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10/16/06 6:56am - Reply: 'How much "Advance" is too much?'
jbova2
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Good Morning, First I want to thank you and everyone who has contributed to this thread.
Finally got to changing out the springs after verifying that max advance was not happening untill well over 4000 RPM. So, when I pulled the rotor I discovered springs the size of GM's largest front coil springs LOL Really big and stiff compared to the Mr. Gasket Spring kit's Gold/Silver/Black ie; heaviest to lightest respectively. We tried the Black, then Silver and back to Black (Lightest) for a result of 8 degrees initial (Engine starts without effort) and total advance is kicking in low at around 2000 RPM (34-36 deg)
Idle is smooth at 750-800 RPM. We are getting really really close to getting it right. I had it fall on it's face one time and thats enough to let me know that we may have to raise the idle in drive to around 900-1000? and perhaps even boot the initial up to around 10-12 deg.
Again Thanks for all of the help and By the Way if anyone needs a set of used coil springs...ConfusedLOL
 
JB
 


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