Too Much Advance?

[Titleist16]

I checked my timing today at school and it showed 27 degrees advanced for base timing at idle. At 3000RPM it was past 60 degrees. Is it ok to run it with this much advance? What should it be running at? I have a 200 with a 264 cam, holley 2bbl, headers, Pertronix ignition, dual exhaust in my 62 comet.

 

[CobraSix]

Personally, I run 12* BTDC at idle. I think the most you really want to run is around 18* BTDC. I would say yours is a little high. Check and make sure that bolt is tightened. I did that one time. Set the timing one night. Next day on the way to work, my car stalled. I get out and luckily I still had my timing light and my timing was set to 30* BTDC.

Slade

 

[simon]

15° checked with timing light and vac advance disconnected (30° with permanent manifold vacuum) made my 250 most happy.

 

[CZLN6]

Howdy Back:

Did you disconnect the vacuum advance before checking the initial advance? If you didn't, you got a reading for both initial and vacuum.

What distributor are you using? Is this a Calif Emissions engine? Is this an Auto trans or a standard? Being at Huntington Beach, CA I'm guessing that you are close to sea level. What is your static compression ratio? Given your cam, you should be able to safely use a little more initial advance due to lowered cylinder pressures.

A stock, 49 states, '66 200 calls for 6 degrees BTDC with a manual trans and an engine with an auto trans calls for 12. Given your cam, you could likely run 10 manual/ 16 auto without detonation- maybe more.

The OEM Load-a-Matic distributors had a fixed amount of advance built into the mechanism- Manual = 15 1/2 degrees, Auto = 13 1/2 degrees. Both by 2,000 rpms, with starting points at 1,000. Any readings outside of these specs may indicate something is worn, torn or otherwise compromised.

Know that changes in cam, compression, carburetion or elevation, and wear will effect these factory specs.

I'll be looking forward to hearing back from you.

Adios, David

 

[Titleist16]

I have a c4 auto and a 68 dual advanvce distributor. I haven't noticed any pinging or anything. I checked it with the vacuum disconnected also and it was about 22-23 degrees advanced. Does it harm anything running this much advance?

 

[CZLN6]

Howdy Back:

No, it should not hurt anything so long as you are not getting any pre-ignition or detonation. Know that pre-ignition can occur without being heard. Be sure to watch for signs of spark plug peppering and/or glazing. These conditions are most likely to happen at highway speeds, when both centrifugal advance and vacuum advance at highest.

Also know that you are likely getting very little performance advantage with this much advance- and likely generating unnecessary heat. You might be doing yourself a favor to establish some performance and economy base lines with your current settings, then back off the initial setting to say 20 degrees and compare. It is a waste of energy to use any more initial then is actually helpful. Too much and the engine is beginning to work against itself.

What have you done with the retard nipple on the distributor vacuum cannister? It has been my experience to leave it open. Which Holley are you using?

Adios, David

 

[cfmustang]

Running that far advanced without pinging? Sounds to me like the damper has slipped and TDC on the damper is not true TDC.

I would test for Top Dead Center and if it is off, remark it on your damper and check timing again.

I know when I did this, I found that my damper had slipped 10 degrees. In my case, when I was setting timing to 13 degrees with a light, I was actually setting it to 3 degrees - causing all sorts of problems...

 

[Titleist16]

where is the retard nipple on the vacuum canister? Also, i'm running the Holley progresive 2bbl which is the 5200 I think. I put new plugs and cap and rotor on it this morning and noticed that when I turn the shaft that the rotor turns on, I can hear a spark. This is with the key on. The Pertronix unit was also pretty hot after only a few minutes of idling. Is this normal?

 

[CZLN6]

Howdy back:

The retard nipple is the one closest to the distributor, between the cannister and the distributor.

When you twist on the rotor, you should be able to move the advance plate. That is normal.

Be sure to check your timing mark for accuracy as per cfmustans suggestion. Strange things do happen.

I cannot help you on the Petronix unit.

Adios, David

 

[mugsy]

I ran that much advance once, by accident, and the car would stall right off of idle :x . It got fun trying to make left hand turns through traffic!!! Anyway, as stated earlier, it doesn't really help anything and might just cause it to stall out. Personally I would go back to the 12-15 range and leave it at that.

Mugsy 8)

 

[wsa111]

You need to start with the basics.

Make sure the harmonic balancer is at TDC & is really TDC. Bring #1 cylinder to the top of the bore & do a quick visual check or better yet if you have the correct tool check to see if you have a true top dead center.

Looks like you are a good canidate for the new DUI distributor from Mike at www.fordsixparts.com.

With your combination you need 14 degrees initial with 24 mechanical degrees in the distributor =38 degrees total. Then the necessary vacuum advance your engine will tolerate.

More spark to you. William

 

[73GreenMachine]

Until I got my car tuned up properly, I had no idea how critically important proper tuning was to a motor. I just went by the method of the greatest amount of advance before pinging. How wrong I was. I took my car to get professionally tuned and actually got the guy to talk me through it. I was running 20 odd degrees of init. timing with about 45 all up. The engine was doing it fine without pinging, but ran twice as good at about 10 degrees advance. The difference was huge.

 

[LaGrasta]

Interesting Green Machine. I too advanced until it pinged. I'm at about 25. My Dad and I messed with it for a while using the timing light, vaccume guage, etc. After all our tech talk, doing it by ear, gave us the most. Granted my mpg isn't that great, about 17-19, and it is proablay due to this advance.

 

[Titleist16]

I'm getting around 20mpg highway. On an unrelated subject, DO I need the vacuum line that goes from my intake to the top of my fuel pump? I cinverted over to electric wipers and I am wondering if I still need that line hooked up or not?

 

[LaGrasta]

no

 

[Anonymous]

rule of thumb concerning spark knock (pre-ignition); on a scale of 1to 10 with 1 being zero knock and 10 being 'holes in pistons are imminent', audible spark knock is around a 7 or 8. A 4 or 5 cannot be heard but damage still happens. This is how we relate it to hi-compression Harley engines so an inline water cooled 6 with normal compression will be a little less disastrous but still bad. Long before you hear the knock power sapping early ignition is happening. Too much advance has the gas doing it's thing before the piston even starts the power stroke. Needs change with rpm which is why timing has to adjust to engine speed.The more advance you run the higher the octane that is needed to keep the gas from releaseing it's power too soon. Octane ratings actually are about the speed that the gas releases power at , the higher the octane the slower the burn- hi octane pushes the piston through it's power stroke adding power with it's follow through while lower octane has more of an explosion.

 

[Anonymous]

I am new to this site and was reading the various posts regarding timing, preignition, etc. I have just finished a 100% restoration of a '68 Mustang Coupe for a good friend of mine and no matter what I do, I cannot get the engine to run with any kind of performance without it spark knocking under varying throttle/load conditions. The engine is a bone stock 200 with the exception of a Hooker Header and dual exhaust. We installed a reman. Ford style carb and dual advance distributor and hooked vacuum from the carb port to the advance side of distributor only. The distributor seems to have about 30 deg. timing in it, 15 vac. and 15 cent. My dilemna is that no matter what combo of initial/vac/cent I try and even if I connect to intake vacuum, I still get fairly regular pinging out of the engine. If I back my initial down to -2 to 0 advance, the ping goes away but the engine performs about as well as my old Farmall B tractor. Absolutely everything on this engine is new, including balancer and this is really driving me nuts. I did have a small crack in intake runner, which has been repaired with an excellent high heat epoxy I found, but I am now wondering if perhaps my pinging may not be the result of a somewhat lean condition being caused by the header installation without the carb being upgraded. I would sure be extremely grateful for any help anyone could offer.

Thank you


Phil

 

[73GreenMachine]

Sounds like you are having the same problem I did. Back in the day before major work on the 200, I was really excited about installing extractors on the motor. I expected to bolt them on and drive away with a very noticeable power gain. How wrong I was (again lol). The car ran like a dog, backfiring through the stock 1 barrel carby and seemed to have less power than before. Bolting on extractors and leaving the intake stock created a lean conditon for my motor. After drilling out the stock main jet about three or so sizes, the bog on acceleration was gone and with the addition of a PVC piping cold air intake from the front light ran the best it ever did before the rebuild. You should be able to advance the timing back up to 15 initial when the carby is jetted correctly.