How much Timing is to much? (2 Viewers)

[PVCsnorkel]

I did the tappet cover gasket on my 2F this weekend including pulling the distributor out. I made sure to put the distributor back in the same rotor position as when I pulled it out. I did not have a timing light on hand to verify timing, so I adjusted it by ear and set it at the smoothest idle. My girlfriend was a little confused as to why it was so much quieter haha. When I restarted the truck afterwards, it took a few extra cranks but otherwise started up and ran fine. Going for a test drive it ran like a raped ape with no odd noises or knocking of any kind.
I'm sure the timing is plenty advanced now, my question is how much is to much? I like the increased power, I just don't want to go overboard and grenade the engine. I'm fully de-smogged with Sniper EFI and the MSD springs in the dizzy.

 

[RevISK]

Is “ran like a raped ape” good or bad?
Sounds terrible but… the context seemed to indicate it was good.

 

[CruiserTrash]

@PVCsnorkel Like I told ya, somebody plotted the advance curve with the MSD springs and it actually retards the timing all the way through the rpm range. @js0k had some thoughts that the MSD springs maybe did some damage to his motor. Jonny wasn’t that one of your head gasket jobs on the dude? I tried it for about two days: felt great right off the line but sucked until about 2200 rpm which is the point where it started sucking even worse. Popped back in a stock dizzy and it came back to life.

Off topic, I know, but we’ve had this chat before my friend!

 

[aztoyman]

It's not stock anymore so don't worry about stock timing spec. What you did is fine. If you have less power, hard starting or ping/knock/detonation, then you readjust. If it runs good, go with it.

 

[PVCsnorkel]

Is “ran like a raped ape” good or bad?
Sounds terrible but… the context seemed to indicate it was good.

Haha It's a good thing.

@PVCsnorkel Like I told ya, somebody plotted the advance curve with the MSD springs and it actually retards the timing all the way through the rpm range. @js0k had some thoughts that the MSD springs maybe did some damage to his motor. Jonny wasn’t that one of your head gasket jobs on the dude? I tried it for about two days: felt great right off the line but sucked until about 2200 rpm which is the point where it started sucking even worse. Popped back in a stock dizzy and it came back to life.

I knew we had a conversation about the MSD springs not working well, I couldn't remember the exact details. I had my extra (stock springs) dizzy on the bench and I was debating which one to use based on our previous conversation. . I believe you and your compatriots experience, I just seem to have had the opposite lol. When I first put them in I had a significant increase in power at 2500. Now it pulls hard all the way through.

 

[PVCsnorkel]

It's not stock anymore so don't worry about stock timing spec. What you did is fine. If you have less power, hard starting or ping/knock/detonation, then you readjust. If it runs good, go with it.

Agreed, I'm not so much interested in the stock spec as preventing a major issue in a few hundred miles when I go up in elevation or am way out on a trail.

 

[aztoyman]

If it pings or rattles you can always dial it back as needed. Usually if it's too advanced it bucks when starting.

 

[PVCsnorkel]

If it pings or rattles you can always dial it back as needed. Usually if it's too advanced it bucks when starting.

What do you mean by bucks?
Also I understand engine knocking, valves tapping and general rattles, I've never gotten a good handle on what "pinging" sounds like, specifically what it would sound like while driving.

 

[Mark W]

I did the tappet cover gasket on my 2F this weekend including pulling the distributor out. I made sure to put the distributor back in the same rotor position as when I pulled it out. I did not have a timing light on hand to verify timing, so I adjusted it by ear and set it at the smoothest idle. My girlfriend was a little confused as to why it was so much quieter haha. When I restarted the truck afterwards, it took a few extra cranks but otherwise started up and ran fine. Going for a test drive it ran like a raped ape with no odd noises or knocking of any kind.
I'm sure the timing is plenty advanced now, my question is how much is to much? I like the increased power, I just don't want to go overboard and grenade the engine. I'm fully de-smogged with Sniper EFI and the MSD springs in the dizzy.

Assuming that the compression is below 10.5 and that the cam is anywhere from stock to 260 (advertised) degrees duration, then the sweet spot is 13 degrees BTDC. As it turns out, placing the indicator ball at the bottom of the window, instead of lined up with the pointer, will give you 13 degrees.

Your particular engine may prefer a bit of variation. But it won't be much unless you are much more modified.

If it seems that the starter is out running the engine on start up... you are much to retarded. Your engine timing that is.

If the engine seems to "buck", chug or fight against itself when it cranks... The timing is too advanced.


It can be hard to hear pre-ignition or spark knock in these engines, but if you hear "bbs being shaken in a coffee can" under heavy load... back off the throttle until you can back your timing down some. Detonated pistons suck.

Mark...

 

[CruiserTrash]

@Mark W I’m following along on this too because advance is one of these mystical engine concepts that goes really deep, and I have a lot to learn.

So here’s my question: what about altitude? Both @PVCsnorkel and I live around 5000’

 

[open country]

I am desmogged and the truck "likes" 11-12 degrees for me. 13 and up I got some pinging. Lots of variables like altitude, engine modifications, gas quality, you name it so not many people can give you an exact "right" figure.

I'd buy a cheap timing light at Harbor Freight/Amazon like I did. If you're going to be tuning and maintaining the truck regularly it's worth it to have precise information on where the advance is.

 

[Mark W]

@Mark W I’m following along on this too because advance is one of these mystical engine concepts that goes really deep, and I have a lot to learn.

So here’s my question: what about altitude? Both @PVCsnorkel and I live around 5000’

Higher altitude will result in lower cylinder pressure at any given compression ratio. This will allow more timing advance. How much more... depends on the engine and how it is used. All of my personal experience is at generally lower altitudes and I have always tuned my engines with that in mind. Personally I would still start at 13* BTDC. Considering that the shorter and longer duration camshafts all seem to like that as a starting point, it is gonna be in the ballpark even at the higher elevations. Bump it up a little at a time and let the engine tell me how much more. I am sure that some of the guys with a heavier engineering background than I have could toss out a formula to use.


Mark...

 

[dbbowen]

I had to advance my DUI dist pretty far past the stock setting in the FSM for it to get it to work. I ended up just adjusting it until it pinged and then backed off and tested it throughout the rev range

 

[PVCsnorkel]

My timing light is currently broken so I'll have to borrow my neighbors for now to verify where I'm at. With a long trip coming this weekend that only goes up in elevation, i feel better knowing altitude shouldnt hurt.
I'm going to drive it this afternoon and listen for any noises and see if I hear anything. At the very least this thread opened a very informative conversation hahaha.

 

[OSS]

I had to advance my DUI dist pretty far past the stock setting in the FSM for it to get it to work. I ended up just adjusting it until it pinged and then backed off and tested it throughout the rev range

Thats the correct way to do it even if you've got a timing light too. Find out where it pings then retard from there .

 

[js0k]

@PVCsnorkel Like I told ya, somebody plotted the advance curve with the MSD springs and it actually retards the timing all the way through the rpm range. @js0k had some thoughts that the MSD springs maybe did some damage to his motor. Jonny wasn’t that one of your head gasket jobs on the dude? I tried it for about two days: felt great right off the line but sucked until about 2200 rpm which is the point where it started sucking even worse. Popped back in a stock dizzy and it came back to life.

Off topic, I know, but we’ve had this chat before my friend!

It would’ve just been a head gasket job but I ended up just tossing in a fresh 2F. Partially due to having 70 thou shaved off that head and continuing to run Colorado timing at sea level I’m sure

 

[BlackCat]

My timing light is currently broken so I'll have to borrow my neighbors for now to verify where I'm at. With a long trip coming this weekend that only goes up in elevation, i feel better knowing altitude shouldnt hurt.
I'm going to drive it this afternoon and listen for any noises and see if I hear anything. At the very least this thread opened a very informative conversation hahaha.

My desmogged sniper'd 2F with a factory dizzy pings at anything over 10 degrees with 87 in it. It's somewhat easy to hear but you have to be listening for it. It kind of sounds like TV static that generally presents itself under lower RPM high load situations. If it isn't pinging at your current elevation, it shouldn't when you go higher.

 

[Rgill]

This is my set up after a ton of tinkering. Desmogged, EFI at sea level with electronic ignition, stock engine. My timing advance is computer controlled so my base timing effects the total advance. Higher then 23 for total advance resulted in pinging which is really hard to hear on this engine (2F). I had to read the plugs to verify I was not getting pre-dentation. Never would describe a 2F running like a raped ape, mine is as quick as a healthy tortoise.
Base timing set at 10 BTDC at idle
Total timing is 23 BTDC at 2500 rpm (Using a adjustable timing light to read total advance)

 

[PVCsnorkel]

My desmogged sniper'd 2F with a factory dizzy pings at anything over 10 degrees with 87 in it. It's somewhat easy to hear but you have to be listening for it. It kind of sounds like TV static that generally presents itself under lower RPM high load situations. If it isn't pinging at your current elevation, it shouldn't when you go higher.

Good to know about your settings since you have the same setup. All I hear right now is my egregious exhaust leak until I get my header put on.

 

[PVCsnorkel]

Finally got ahold of my neighbor and got his timing light, 24 hours before a 4 day trip.
I believe I was at 15 degrees, but I dialed it back to a confirmed 13 just to be sure. I cranked it all the way advanced to hear pinging, and y'all were right, it is hard to hear. Even with my head next to the block I could barely hear it.