Pinging; What does it sound like? (1 Viewer)

[88bj73]

As the title suggests, what does pinging sounds like from our 2F engines while sitting in the driver seat.
I think i may have pinging but from what i've read/heard it's pretty loud. Mine is not loud. My fuel level in my carb is lower than normal. I need to change the float level, could this cause pinging?

Any help is much appreciated.
I'll be adjusting the valves tomorrow getting my timing perfect. By the way... I'm Desmogged all the way with a Trollhole carb.

 

[TallCanDan]

My opinion: In a vehicle with a carb, I always run at minimum mid grade gas (89 octane). That goes for our 60 and our '76 Blazer. 87 octane will, in my experience, cause pinging (which I believe the proper term to be pre- detonation). This is considering your timing is within specs, as poor timing will cause pinging. Pinging is the piston actually rattling in the cylinder, so it would sound as just that, rattling.

Danny

 

[jfnall]

I had the same problem and it didn't matter how high I got on the octane level, it still pinged. I wasn't very loud and only pinged when going uphill or taking off from stopped. I opened up the idle mixture screw and it went away. The ping can be caused from running too lean.

 

[freepowder]

Sonar?

 

[TS888]

It's a rapid "tinking" noise. Imagine putting a couple small ball bearings in a highball glass and shaking it with your hands wrapped around the glass to dampen the sound.

 

[jfnall]

Get all the normal stuff set. Timing at 7 btdc. Plugs gapped correctly. 91 octane. No vac leaks.

My idle mixture screw is out 6 full turns. At 3-3.5 turns it pings like crazy.

 

[TheJackRabbit]

My 87 2F does not like 86 octane and I operate at 7,000 to 10,000 feet. I read that high altitude requires less octane and am not prepared to debate the point. I can say the 2F likes 88 octane fuel.

 

[Trollhole]

Yes your fuel level needs to be in the middle or close to it. What is your timing set to? how is your vac advance on your dizzy set up?



Best thing is to give me a call and let me go over your concern. 864-414-0563

thanks Marshall

 

[Zhenya]

My opinion: In a vehicle with a carb, I always run at minimum mid grade gas (89 octane). That goes for our 60 and our '76 Blazer. 87 octane will, in my experience, cause pinging (which I believe the proper term to be pre- detonation). This is considering your timing is within specs, as poor timing will cause pinging. Pinging is the piston actually rattling in the cylinder, so it would sound as just that, rattling.

Danny

The "pinging" noise is NOT the piston rattling around in the cylinder. How could it? If your tolerances were so bad it could do that, you would have NO compression.

The rattling noise is the flame front hitting the piston while it is still moving up as opposed to at TDB (slightly before or after). The noise is the dissipation of the energy as it has nowhere to go because the piston is still moving up. Alternatively, if the force create by the early ignition is strong enough, that energy will be dissipated via a bent rod, broken piston rings, crack piston or even a blown block.

http://en.wikipedia.org/wiki/Engine_knocking

 

[jfnall]

I gathered a lot of info on google with "pre-detonation" as well. I did all the right stuff to make it go away, but until I got away from running too lean, it never changed.

 

[TallCanDan]

Correction noted, thanks.

 

[Lugal]

FYI, when my 2F pings it sounds like I'm shaking a few marbles around in a coffee can.

 

[jfnall]

And it isn't very loud either. I thought mine was a rattling part under the hood for a while.

 

[88bj73]

Update! I adjusted the float on the carb... Noticed an improvement on start up.
Did the valves and noticed an improvement but not as much as i was hoping. Sounds kinda like a diesel now.
Can anyone tell me the order of the valves? Intake/Exhaust? I may have done them wrong...
Set the timing to 10*... And i'm pretty sure it pinged like crazy! Now i know what it sounds like and it doesn't sound good. Filled up with premium grade 91 octane gas. Set the timing back down to 7* and no knocking with a little improvement in power.
So... Running heaps better now! But it seems in the 2-3k range going uphill i get slight pinging. I'm going to switch the lines on the distributor advance to see if that does the trick.
Another day another problem with my 60... I think i may have to start a build thread or maintenance thread to document all i'm doing and will do in the future.

 

[TS888]

Valves sounding like a diesel suggests you didn't get them right. At least two members have FSM links in the sigs (Spike Strip and GregNash?). Get the valve adj info there.

Vacuum line s/b to inner nipple on the dizzy. Outer is for high altitude compensation, which you likely removed in the desmog, and don't really need in the PNW.

 

[klinetime574]

Valves are counted from the front of the engine to the back. Thermostat housing to firewall. Harmonic balancer to rear main seal. Any way you want to phrase it

It takes a couple doings before you get good at it. Give it another shot when you have the chance.

 

[Dynosoar]

Front to back Ex, In, In, Ex, Ex, In, In,Ex, Ex, In, In, Ex Adjust intakes to .008 and Exhaust to .014"


Dyno

 

[88bj73]

I'm assuming you do the intake ones first? I tried the exhaust first and couldn't adjust past number one...
I didn't follow that order but followed one Jim c. put up. I don't know really how it works but I was able to do them per his numbers... So I thought that was the way to do it. Obviously I was wrong since it makes a considerable racket. Kinda like my old 3b...
Cheers guys!

 

[Dynosoar]

The order I listed is the physical order of the valves not the adjustment order.

Dyno

 

[88bj73]

The order I listed is the physical order of the valves not the adjustment order.

Dyno

What's the adjustment order? I can't seem to find it anywhere...