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.

[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''?

[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''....