Have to get my upgrade & tunes....NOW

[Jackpine]

Darren, I'm pretty sure he was hearing "ping" (probably under load), if you read the first post carefully. I don't think he had the other symptoms you mentioned.

- Jack

[DarrenWS6]

Originally Posted by JackandJanet

Darren, I'm pretty sure he was hearing "ping" (probably under load), if you read the first post carefully. I don't think he had the other symptoms you mentioned.

- Jack

Ok thanks. I should probably study these things further. I never understood what 'ping' is, is that when WOT and the rev limiter is bouncing off?

[Jackpine]

Originally Posted by DarrenWS6

Ok thanks. I should probably study these things further. I never understood what 'ping' is, is that when WOT and the rev limiter is bouncing off?

No, "ping" is preignition. The fuel/air mixture is igniting just a tad too soon (before top dead center) and the expansion is happening too fast as the the piston is reaching the top of it's stroke. Basically, the gas is trying to expand just as the piston is doing its best to compress everything. The result is a sound that's like rattling marbles in a can. Once you hear it, you'll never NOT know what it is again.

Since the gas is expanding as the piston is trying to compress the mixture, there are severe stresses on the rods and the cylinder walls (mostly the rods, I think). It also heats things up quite a bit. A lean mixture can bring on ping, even when the timing is exactly according to specs. A "little" bit of ping now and then is no problem. But, heavy ping can destroy your engine. It of course also robs you of power, since the expanding gasses work against the desired movement of the pistons.

- Jack

[DarrenWS6]

Originally Posted by JackandJanet

No, "ping" is preignition. The fuel/air mixture is igniting just a tad too soon (before top dead center) and the expansion is happening too fast as the the piston is reaching the top of it's stroke. Basically, the gas is trying to expand just as the piston is doing its best to compress everything. The result is a sound that's like rattling marbles in a can. Once you hear it, you'll never NOT know what it is again.

Since the gas is expanding as the piston is trying to compress the mixture, there are severe stresses on the rods and the cylinder walls (mostly the rods, I think). It also heats things up quite a bit. A lean mixture can bring on ping, even when the timing is exactly according to specs. A "little" bit of ping now and then is no problem. But, heavy ping can destroy your engine. It of course also robs you of power, since the expanding gasses work against the desired movement of the pistons.

- Jack

Thank you for the explanation Jack. I have a better understanding of this now, and have not experienced it and hope things stay that way.

[BlackSTX]

Jack, you explained it well. I actually seemed to be doing fine on acceleration, it was at a steady speed I was actually noticing it, and for a brief moment when you let of the gas to reduce some speed. Either way, it's not a good thing as it indicates a lean condition.

[Jackpine]

Originally Posted by BlackSTX

Jack, you explained it well. I actually seemed to be doing fine on acceleration, it was at a steady speed I was actually noticing it, and for a brief moment when you let of the gas to reduce some speed. Either way, it's not a good thing as it indicates a lean condition.

Odd that you hear it when you let up on the gas, because, as Cody pointed out to me once, you are really closing down the air intake then (in a gasser). I'm surprised you don't hear it on acceleration. But, hearing it at steady speed is not good at all, especially if it didn't go away when you backed off the timing.

- Jack

[BlackSTX]

Yeah, I was surprised too, but it made me send it in for the upgrade and a tune ASAP. Which that in itself will be a good thing.