Interference engines... all makes...4000Q is not interference BTW

[SuffolkD at aol.com]

Jonathan:
I'll take a shot at this not knowing the exact answer.....
Its related to valve float.
The faster the engine is turning, the more the valves travel a wee bit 
further against the spring that retracts them.  Go fast enough and the inertia will 
cause the very close tolerances at idle to become in contact.

FWIW:  The JT? (85-87) 4000Q 5cylinder isn't an interference engine.  Mine 
broke at a stop light intersection and all's well.  high RPM might have been a 
different story.......
Do that in a MC 1 or 2 or any turbo engine and you're toast, per se.

HTH - Scott by BOSTON

> From: Jonathan Farrugia <>
> Subject: Re: 
> Cc: quattro at audifans.com
> Message-ID:
>     <Pine.SOL.4.58.0503210155460.8519 at zektor.gpcc.itd.umich.edu>
> Content-Type: TEXT/PLAIN; charset=US-ASCII
> 
> can someone explain to me how an engine is not interference at idle but is
> a higher operating speeds?
> 
>