MR2 Question.

Von Smallhausen · 9 Jul 2006 at 23:47

I have heard that should the cam belt go on an MR2 then it is so designed that the valves will not go with it and the only thing to replace would be the belt itself and it wouldn't effectively knack the engine if it happened.

Does any MR2 owners or others know any more about this or have any info.

Cheers.

eidolon · 9 Jul 2006 at 23:49

In theory that's correct. The 3SGTE is a non interference engine so you shouldn't bend the valves if the cam belt should snap although I'm not sure if I'd like to be the one to test it out

Von Smallhausen · 9 Jul 2006 at 23:50

eidolon said:
In theory that's correct. The 3SGTE is a non interference engine so you shouldn't bend the valves if the cam belt should snap although I'm not sure if I'd like to be the one to test it out

Agreed totally.

I am not saying it to verify and skimp on servicing, I am just curious and think it impressive if it is so designed.

Dogbreath · 10 Jul 2006 at 08:13

Von Smallhausen said:
Agreed totally.

I am not saying it to verify and skimp on servicing, I am just curious and think it impressive if it is so designed.

It's not especialy impressive tbh. Modern DOHC engines aren't designed to be "interference", it's a side effect of designing the engine for good performance and economy, i.e. high compression ratio, high valve lift, compact combustion chamber, lots of squish etc.

Being turbocharged, the 3SGTE has a low compression ratio to start with, and relatively mild cam timing/lift so it has a good advantage from the start.