replacement engine

[jamieo]

Hi, the big end has just started to go on No1 piston on my 2000 engine. I understand that the early engines are less robust than the later ones so to be expected.

I think I can replace the bearings for now, but want to get another engine, overhaul and replace. Could someone let me know which/when the engines were improved (better oil circulation I understand)?

Thanks

[vinp182]

2005+

[vinp182]

The block is the same tho so if you are doing a full rebuild then just use 2005+ parts (I assume that’s all you can buy these days)

[MRHAPPY62]

or just fit a 2zz

[jamieo]

thanks for the quick responses - so what is different on the 2005 onwards?

[Topdownman]

Isnt it something like an extra oilway on the piston?

[carolineasb]

There's extra holes in the piston grooves (some people have retro-fitted extra holes although I don't know how much success they have had) and I've also been told that there is some sort of "Teflon" coating that was added to the cylinders.

It's not quite as easy as saying 2005 on cars that have the second upgrade :( there is a file on the UK MR2 Roadster page on FB that has the engine number we think was the start of the second upgrade run.

When we had to replace the 1zz in our Y reg, we got a 2006 engine from Dick Sloan in Carlisle (dick2ski? on this forum) and, from checking that file, it appears to be a last upgraded engine

[jamieo]

So sounds like pistons and new Teflon coated block? Thanks for the insight.