is the 4efe/5efe and interference engine or non interference?

[hill_bill10]

ok so i read on autodata that the engine IS an interference engine, but have been informed recently that it isnt, so i just wanted to clear this up

does anybody have an opinion on this? is it or isnt it?

[LukeH]

have read it was non interference from joz, iirc.

think the info is in ryan langs build thread

[Jozinobi]

I can confirm our engines are non-interference because I have been through the experience of my cambelt 'properly' snapping in two on a regular 70mph cruise running in a new FHE hybrid engine and no damage was caused to my internals (thankfully).

It was caused by the quality of the belt itself and not my mechanic/installers fault. This was a new item.

I'm no expert but after three engine builds my opinion is our cars do not require regular belt or 'chain' maintenance that would affect timing if left unmaintained/unchanged for a long period.

Whereas interference engines do, such as those needing chain belts or others where timing accuracy is absolutely vital.

It is gradual/outright incorrect timing that would cause the valves and pistons to collide at their lowest point thus causing the 'interference'.

Damage includes bent valves from the piston colliding with them, pieces of shattered valve or piston causing damage within the cylinders possibly damaging the rods.

As you can tell, our cambelt service periods are far and few, which comes to the conclusion that Toyota intended our 'E' engines to be non-interference considering the long cambelt service periods as indicative proof.

My advice, always use original toyota parts when it comes to service items especially cambelt kits, not usa eBay spurious from my experience.

Only upgrade I'd recommend/mention is the Power Enterprise cambelt as it is intended to be stronger than oem (is expensive).

As long as you use decent parts and have them installed and timed properly there is far less chance of things going wrong.

Maintenance is also the key. Keep your eyes on any leaks and fluid levels and all will be dandy.

Hope this helps.

Joz