Petevb

This gets better and better... The 997 GT3 used the Mezger to the end, through the 4.0. The 991 GT3 is the first GT3 to get the 9A1.

Anything else?

Perhaps you should simply look it up for yourself: https://www.stuttcars.com/technical/pet/

jimbo1111

Those two heads you posted in your second picture look radically different. They just don't look like they would mate up to the same block.

Petevb

I get that you're confused... What are you asking?

Did you follow this link posted earlier in the thread?
https://rennlist.com/forums/991-gt3/854299-991-gt3-vs-carrera-s-engines-differences.html

jimbo1111

Pretty simple actually. Looking at the two heads side by side one would never guess that they can mate up to the same block. That is if they both share the same block. That is why I questioned the accuracy of the diagrams.

Petevb

That's pretty simple too actually: In those images you're looking at the back side of the head, the part that faces away from the block, not the front that mates to the block. Possibly a small part of the reason you're confused.

Follow the link I posted at the top of the page and you can fact check to your hearts content.

drmatara

Yes indeed but not in the 997 GT3...

jimbo1111

Thank you. That seems to be a wonderful resource.

jimbo1111

That makes sense. Did you notice the orientation of the cams. They are in the same direction. Kind of weird.

Larry Cable

but never in the 996 nor 997 GT3s, which was the point of contention.

NoGaBiker

Not meaning to take sides here, but you did specify the 997 GT3, which never received the MA1 (actual name for it, not 9A1).

jimbo1111

Got it. I never was into the GT3 cars until recently. Sort of counterintuitive as to why Porsche wouldn't use there latest engines in racing.

Larry Cable

that's the $64k question! - many conspiracy theories ... I haven't heard any that appear particularly compelling ...

having said that it makes me feel good that the trusty old Mezger is still banging away in a 911 race car somewhere...

what would be truly EPIC would be if the 991 RS had a Mezger in it! (zero chance of this of course ... )