How come my Griffith 500 often pops and in acceleration?

[panic]

What could be the reason why my engine suddenly starts popping strongly in acceleration and often it doesn't even pull as usually? Could it be due to a wrong timing?

Thanks.

[gruffalo]

I had this on aRV8 engined car, it was down to the exhaust lobes on the cam being worn almost round so it ended up exhausting through the inlet valve.

[panic]

gruffalo said:

I had this on aRV8 engined car, it was down to the exhaust lobes on the cam being worn almost round so it ended up exhausting through the inlet valve.

But then, how come it doesn't always pops but only time by time and, often, it goes from ''smooth mode'' to a disgraceful ''full blown popping mode''?

[Hoover.]

what do you mean by "pop" ?

[panic]

Hoover. said:

what do you mean by "pop" ?

Like a heavy misfiring in acceleration...sometimes in deceleration and even when in neutral gear if you give throttle you can listen to a misfiring...

I called it ''poppings'' but maybe it was more right to call it ''misfiring''....

[UKAuto]

Mine was doing the same, drive it gently it would be ok - pulled away pretty good but would pop. Certainly down in power from before.

It landed up one lobe in particular was almost gone, with the rocker off and engine turning over all the other rockers were moving the way I would expect, this one you had to rest your finger on it to feel that it was moving at all.

New cam in the next few days, strip down started Friday.

[eff eff]

I would start by checking out the ignition system, distributor, coil pack, HT leads and plugs

[e635815]

Pops during acceleration usually means too much ignition retard ( or not enough advance, which is the same really).
Instead of burning in the engine, I the fuel burns in the exhaust and produces pops and bangs.
Did you alter the ignition lately? Can you verify the settings?