Re: Jump Timing?

[Jon Pike <jhpike@xxxxxxx>]

> Hi Alan:
>
> Sounds like time for a new, and perhaps more honest and/or knowledgeable, 
> mechanic.  Your Alfa's engine has 2 timing chains, not a belt, and as far 
> as I can recall, that timing chain isn't going to jump and cause cam timing 
> to be changed.  Even if it did, you likely wouldn't get away with bending 
> just two valves as you continued to drive.  Since all 4 cylinders, and 
> hence all 8 valves, would have the same timing, you'd either bend 4 (all 
> intake, or all exhaust) or all eight valves.  You could certainly ask your 
> "mechanic" how he's ascertained the damage, such as a compression test, 
> visual inspection, etc., but to me, that's wasted time.  Without removing 
> the cylinder head (not to imply that's even necessary, anyway), his 
> estimate isn't worth anything, either.  Push, tow, or drag the car to 
> someone that knows Alfa's and values his clients.
>
> If you can tell the Digest where you're located, I'm sure one of us can 
> point you in the right direction to finding someone to check your Spider out.
>
> Regards,
>
> Dean W. Cains
I'll give a loud second to this, as well!  If you lost cam timing at 100 
mph, you would have had such catastrophic engine failure (breaking off 
all 8 valve heads, beating the piston crowns to fragments, eating your 
rods, etc) that you'ld probably see parts behind you on the road, if not 
flying thru your hood.

The only way for the chain to slip, is if the tensioner came loose, and 
you would likely have heard lots of noise before the big disaster.

My experience with this, where a mechanic managed to get the chain to 
jump a tooth or two when the engine wasn't running, resulted in two 
valves being bent when the starter ran the engine a quarter revolution.
Dosent take much.

I hope your "fiddling" mechanic didn't do exactly that..  play with the 
tensioner the wrong way, get the chain to skip, try to start the car 
without turning it over by hand to check..  rrrrrrrTHUNK!  "Uh, I have 
determined you need a $700 valve job".

If so, do what Dean suggests, and get the Fiddler to pay the Alfa 
mechanic for the valve work!

Good Luck!

Jon
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