y_p_w wrote:
>
>
> jim beam wrote:
>
>> FanJet wrote:
>>
>>> "jim beam" > wrote in message
>>> ...
>>> Belts are certainly good for $dealerships$. Their replacement isn't
>>> preventive maintenance, it's scheduled maintenance - big difference.
>>> If Honda used a decent chain, the customer wouldn't need to deal
>>> with it. The Q45 issue was an anomaly. I'm sure there's the
>>> occasional Honda spun bearing or some other oddity. Maybe the
>>> customer ought to replace them every 80K.
>>
>>
>>
>> if you drive some piece of v8 detroit iron with less than 40 bhp per
>> liter, you're not going to notice much difference with a bit of chain
>> stretch. and cam timing errors in excess of 10 degrees of crankshaft
>> are not unknown. belts don't stretch so they remain dead-on with
>> timing right up to replacement day. you want a high performance engine?
>
>
> One forgets that chains put a certain amount of stress on motor oil.
> If people are lax about their oil change intervals and/or use poor
> quality oils, chains have been known to crap out. Chains create
> their own difficulties with OHV engines. Belts don't need any
> lubrication.
>
that's right - the longer travel for overhead cams is a much bigger deal
for a chain at high revs than for a belt. belts have much less mass.
chains for block mounted cams where the runs are short are just fine.