bumping timing up without timing light...

[5.0Flareside]

i was thinking bout bumping the timing up a lil bit on my truck to see if i can get a lil more out of it. as im really down on power. now do yall think i should do it with a 230k mile motor that i have? but it doesnt leak oil and it dont use oil. and idles smooth. i think i may be losing compression but not sure. is it safe to bump timing up? will it quicken the compression loss if i am loosing compression? and about how much should i turn the distributor to bump it 2 degrees? like just barely turning it like 1/20th of a turn or more or less what? im thinking bout barely bumping it gradually till i hear pinging when im driving it. is that the way i should do it without a timing light. i just dont feel like having to go through all the trouble of using a timing light and marking the timing marks and etc. me and my dad both agree timing by ear is just as good.

 

[Skandocious]

I don't recommend timing by ear. Pinging will not always be easy to hear and it generally only happens during specific driving situations (like pulling up a steep hill). I advise against doing it by ear-- just borrow a timing light from someone. Pushing it too far and not knowing that you're pinging could damage your engine.

 

[5.0Flareside]

what is pinging actually? is it pre detonation? or what?

 

[Skandocious]

Ping stands for Pre IGNition. When you adjust your timing you're adjusting the point at which your spark plugs are firing in relation to the position of your pistons in the cylinders. Stock timing is 10* before top dead center which means you are firing the plugs 10 degrees before the cylinders reach the top of the compression stroke (10 degees meaning the rotation of your crank). If you adjust the timing to far, say to 18* btdc then your plugs will ignite too soon-- pre ignition.

 

[5.0Flareside]

i figured that was pretty much the definition. no how will it cause damage?

 

[DNFXDLI]

Pre-ignition means that the gasoline/air mixture ignites before the sparkplug has fired...it can happen from incorrect heat range of plug, carbon buildup in the combustion chamber or other things.

 

[Skandocious]

Sorry-- Duncan is correct. Pre ignition is a different phenomenon. Though the rest of what I described about pinging is still true.

http://en.wikipedia.org/wiki/Engine_knocking#Causes_of_pre-ignition

 

[DNFXDLI]

That's a good write-up!

 

[1985 Ford F-150]

It wont hurt it unless its doin it all the time. If it starts pingin after ya mess with it go to the next octane rating when ya get gas. When your doin this roll up the windows and turn the radio off then find a fairly steep hill and floor it if it pings then ya either need premium fuel or bump the timing back. I go through this everytime I build a motor so it aint nothin new. Its really hard to describe what it sounds like on here.

 

[Skandocious]

Like I said before-- pinging is not always audible so just because you don't hear it doesn't mean you're not damaging the engine. The safest bet is to just use a timing light-- to me the risks outweigh the benefits.

 

[HazzardMadWolf]

i figured that was pretty much the definition. no how will it cause damage?

I'm subscribing to this thread because all of the guys that I raced with tuned thier engines by ear, and they did very well (Fords of coarse). You guys didn't answer Chris' question, How does it cause damage?

 

[5.0Flareside]

I'm subscribing to this thread because all of the guys that I raced with tuned thier engines by ear, and they did very well (Fords of coarse). You guys didn't answer Chris' question, How does it cause damage?

yeah. thats how my dad has ALWAYS timed his engines. and he's never had issues.

 

[DNFXDLI]

Causes damage by trying to shove the piston down the wrong way...In the past, I have set the initial timing by using a timing light, then advancing it degree by degree (using a timing light) and going for drives while listening for detonation and then backing the timing off a degree or two.

 

[Skandocious]

From the link I posted earlier:

If detonation is allowed to persist under extreme conditions or over many engine cycles, engine parts can be damaged or destroyed. The simplest deleterious effects are typically particle wear caused by moderate knocking, which may further ensue through the engine's oil system and cause wear on other parts before being trapped by the oil filter. Severe knocking can lead to catastrophic failure in the form of physical holes punched through the piston or head (i.e., rupture of the combustion chamber), either of which depressurizes the affected cylinder and introduces large metal fragments, fuel, and combustion products into the oil system.

 

[DNFXDLI]

 

[HazzardMadWolf]

Sorry Chris, must not have refreshed the page soon enough. Good explanation.

 

[1985 Ford F-150]

Key word there is extreme as in race motors or towin alot over mountain passes. It aint hard to hear a ping if ya know what it sounds like. For what he does with that truck hell be fine tunin it by ear. Just be sure ya dont move it very much at a time. Heres a couple of links to help with it. Theyre mainly for spark plugs but the one shows ya what to look for on em to tell what your timin needs to be.
http://www.dansmc.com/spark_plugs/spark_plugs_catalog.html
http://www.4secondsflat.com/Spark_plug_reading.html

 

[D427COBRA]

Sorry to butt in, but is this an EFI or carbuerated engine? The reason I ask is the ignition is controlled by the computer on EFI. If you "tune it a couple of degrees" the computer will probably take it out. No gain.

 

[Skandocious]

We're talking about the base timing. The computer does it's timing calculations and adjustments irrelevant of the base timing. The adjustments just have a different starting point if you adjust the base timing.

 

[Fellro]

The damage that can occur from both pre-ignition and pinging is holes in the piston. Seen it, blew at least a 1" hole through the middle of the piston. Preignition can blow the ring lands out too, if that is the source of the ignition...