Timed too high for greater power........

[jxavierf]

My friend (a mechanic) who I used because he has a timing gun and also knows more than me, adjusted my timing after I installed a new disty. He timed it high saying that it would generate more power, but said I must use high octane gas (91 or higher). Well I definitely feel the car has more power; however, I noticed in hard acceleration I can hear the carb give off the "I need more juice" rattle.......so I went to grade 93 octane......still the rattle. I think my friend just timed it too high, so I would like to drop it just a tad so that the system is comfortable with 93 or 91 octane. Could I just untighten the lock down bolt on the disty, give it a slight turn, therefore, decreasing the gap....problem solved? Or do I have to go thru the whole timing cover off, timing gun job?

 

TIA

[NorthWet]

What type of vehicle? Which engine? Which Year?

 

Regardless, the timing light is what you need to use. Depending on the vehicle, you may need to do something electrical to let the engine get timed. (This is usually with EFI, and you imply that yours is carbureted.)

 

Advancing the iginition timing in and of itself will not get you any more power. Adjusting the ignition timing to optimize your car's fuel grade, C/R, and driving conditions can help a little.

[jxavierf]

Its an 84 wagon 4wd gl auto....and yes carb. So what then happens when you twist the disty clockwise or counter-clockwise......I noticed that if you turn one way the engine runs faster, the other way, and it runs slower................what is actually happening? To my understanding you are lengthening or shortening the firing distance....is that correct?

 

Thanks............

[NorthWet]

What you are doing is changing when the spark occurs relative to the position of the moving piston. Gasoline/air takes a finite amount of time to burn, and it takes time for the flame to spread to all of the mixture. It you were to time the spark so it occured when the piston was at its closest approach to the head (Top Dead Center, TDC), then the piston would already be moving away before the flame really got going and was producing pressure.

 

So, the spark timing is set to happen before the piston gets near the head, so that the flame is just really getting going when the piston reaches TDC, optimizing the pressure pushing the piston away.

 

This is a balancing act and a compromise. Since we are starting the combustion before the piston is in a position to make power, we are wasting some energy pushing the piston away. If the spark occurs too soon, the pressure rises too much and pushes the approaching piston away too much, plus the pressure and temperatures can increase enough that detonation (pinging, knock) occurs.

 

When you turn the distributor, you change when the spark occurs, and the engine responds by producing more or less power... at IDLE. But good idle timing doesn't translate well into good higher-speed/-load timing. You really need a timing light so that you know how close you are to what the manufacturer specified.

 

Sorry for the wordiness...

[MorganM]

Take it back to the duder and politly ask for him to back it off a few degrees. I'm sure he'd do it for ya; heck he might let you do it if you ask I've had cool shops let me use their timing lights for a few minutes while they were busy doing billable work.

[kingbobdole]

Hey....

On my 6 my ignition is turned all the way advanced and I run premuim with no issues... makes lots more powA! Anyhoo, the timing light is the way to go, but you can also do it by ear. On old VWs I personally think you could get the timing more right by ear per engine then with the light. Lights tell you EXACTLY where it is, making it much easier to test and tune, but carry your wrench around a bit moving the dizzy a few degrees at a time and see where it runs best.

[Myxalplyx]

How did it go? Did you turn down the timing a bit? Follow the advice of the posts earlier in this thread. You want to turn down the timing slightly. Turning up the timing does make for extra power on premium grade gas though.