Non Interference Engine

[lovlex]

what year was this type engine stopped at, in the sc 400 and ls 400?

thanks

[1990LS400]

You might want to review old posts since this has been discussed many times although sometimes with inaccurant statements. My understanding is that anything before the VVT-i engines are non-interference engines. I think the first year for VVT-i in the LS was 1998 and that 1999 was the first year for VVT-i in much of the rest of the Toyota line. I know that our 98 Camry V6 is not VVT-i or interference. When the timing belt broke in my 1990 LS, no damage was done. The best course of action is to replace the timing belt as recommended for the particular year in question.

[95LS400Bob]

After a similar post on interference and non interference engines..I did a ton of searching but could find little to back up whether the engine were or were not. I found a site that sold timing belts and their chart shows DOHC Lexus is an interference engine. But I find nowhere else to back that up.

I've been through all the Lexus manuals and the changes in the 95's. The valve timing events are longer and the compression higher on the 95 engines. If the 94's back were non interference...then it is quite possible the 95's were interference. But I have no solid data to back that up. And nothing solid to say the 95 back were non interference.

So I would treat them as interference as a safety precaution. But really..who wants to gamble in this area of timing belt replacement? If the motor were to break a timing belt and not damage the engine (non interference)...Murphy's law would make sure it didn't happen where Lexus parts are conveniently available and

then you get to replace it anyway. Perhaps beside the road. Perhaps after waiting 2 days in a motel room for someone else to do it.

Just not an area to gamble in my opinion. Just my 2 cents.

[ec437]

After a similar post on interference and non interference engines..I did a ton of searching but could find little to back up whether the engine were or were not. I found a site that sold timing belts and their chart shows DOHC Lexus is an interference engine. But I find nowhere else to back that up.

I've been through all the Lexus manuals and the changes in the 95's. The valve timing events are longer and the compression higher on the 95 engines. If the 94's back were non interference...then it is quite possible the 95's were interference. But I have no solid data to back that up. And nothing solid to say the 95 back were non interference.

So I would treat them as interference as a safety precaution. But really..who wants to gamble in this area of timing belt replacement? If the motor were to break a timing belt and not damage the engine (non interference)...Murphy's law would make sure it didn't happen where Lexus parts are conveniently available and

then you get to replace it anyway. Perhaps beside the road. Perhaps after waiting 2 days in a motel room for someone else to do it.

Just not an area to gamble in my opinion. Just my 2 cents.

←

still, making a 10:1 compression 250 hp V8 that is non interference is pretty crazy.

[kamtra]

Your research was correct. The 95 was first year of interference due to a new head design. 90-94 are safe. Tis why i had no qualms about changing my own belt. So, for everyone: 90-94 non-interference. 95 and up will smash your valves into your pistons if your belt breaks. Good luck!

[Jim Stariha]

Would a 1993 SC 400 have the same engine?