Re: V6 Timing Belt

[Alex Jenner <alexj@xxxxxxxxxx>]

Graham wrote:
>
> With all the problems with the Alfa V6's timing belt, I
have to wonder, why
> can't the belt be converted to a chain? It must be
possible to have toothed
> cam ends, crank end, and dizzy drive ends made up, and
fabricate a
> tensioner. I guess it must not be viable for one reason or
another, or
> someone would have already done it. Just thinking out
loud.

I think issues of lubrication may already have been
mentioned.

However, I've been wondering about what is the real problem
with the original design. Most belt driven overhead cam
engines are not this fussy - no problems turning backwards
etc. Unless you forget to change the belt at the prescribed
interval, engines like the old Fiat 128 just seem to last
and last. We're talking mainly about problems with the 12v
engine here aren't we? Does the 24v have the same sort of
problems with belts?

Isn't it true, that a large part of the problem is that on
at least one of the cam wheels there is only about 60
degrees of contact between the cam sprocket and the belt -
if that? So why doesn't someone come up with a different set
of idler wheels and mounting kit to mount them in new
locations, in conjunction with a longer belt from another
car, that gives at least 90 degree contact?

Heck lets make it 120 degree contact.

Not a simple project, but more practical than conversion to
chains, and if it works the inventor would probably find a
ready market for the conversion kits.

Come to think of it, what do the race guys do. The risk of
an engine turning backwards in a spin must be quite high -
yes I know you're meant to push the clutch pedal in a spin,
but the penalty for getting it wrong seems too high. Maybe
some are already doing some sort of modification like this?

Best Regards
Lex Jenner

2xAlfasuds with belts that don't slip.
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