my93Pathfinder

Can anyone tell me why Nissan used a timing belt instead of a chain for our Pathy engines (the VG30 and 33s)?
Chains are more durable and much less likely to snap and cause a piston to eat a valve.
Belts must be replaced every 60,000 miles (an expense I'd rather not pay).

Since the VGs (in the trucks anyway) don't need to rev that high, the chain seems much more practical. At least Nissan's reliability and durability somewhat offsets the fact that they can be a PITA to work on.

__________________
God must love stupid people; he made so many of them.

Zilverado

You may be right about the durability of the chain vs. belt - - but either way, they can eventually fail. My vote is to avoid the "interference" engine and eliminate the valve-eating piston situation.

I agree with you though, that it's a good thing these engines were designed to be reliable.

__________________
Zilverado
1992 Pathfinder V6-SE 4wd

lewisnc100

Not much consolation but if your 93 was made in the 7/93 production month or later you've got a 105k timing belt instead of a 60k belt.

__________________
1997 Pathfinder XE
Air Lift Air Bags, Warn Hubs

Animal

I would have preferred a chain and I was never certain why engineers ever came up with the belt design, other than weight and cost. Whatever the reasons, we are stuck with it.
As a technical instructor for many years, I used to tell students who made comments like "that was a stupid design" that they should build a better one and be rich, but until then, the question isn't why but to fix it when it breaks.

__________________
Life is too short to take it too seriously

colinnwn

Belts run quieter and take less room. Chain setups are more complicated and expensive to manufacture.

A properly engineered interference engine can get higher performance and better fuel economy than an otherwise identical non-interference engine. Basically it means they were able to package everything tighter, allowing a higher compression ratio.

Personally, I would prefer a interference chain engine. Of course direct gear drive would be the coolest. I owned a IHC Scout that had an engine with gear drive cams. It had sodium filled valves too. That stuff was high technology when it was designed in the 60's.