Toyota MR2 Message Board - View Single Post

CpuZapper · 04-09-2009, 02:19 AM

Left is either a GZE or NA from an '87-'90.
Right looks like a smallport GZE.

And the middle could be a late model 16v NA smallport. They did make those with oil squirters, from 1990 on I believe. Though it is either missing a pin retaining clip, or it's one I don't recognize. I rambled, let me try to bring my thoughts together...

IN THE US:
The early 4a (technically up to 87ish, they built some using left over parts) had a 5 rib block, 40mm rod journal, and 18mm pressed in wrist pins. These are most easily identified by their lack of pin retainer clips, and their inability to be separated from the rod without a press. The later model motors - all 16v after as far as I can recall - used a 7 rib block 42mm rod journal, and 20mm floating pins, which require the retainer clips. The oil squirter blocks were available as both the small port NA used in a few cars, and the small port AE101/AE111 SC motors. I've seen factory built motors with 7 rib blocks, and older 40mm/18mm rotating assemblies though. There were also some changes to the oil pump over the years.

I think that's right... it's been way too long since I had to remember all that. Anyways, almost all the rods, the blacktop 20v excluded, are pretty stout. Stock rods hold up rather well, even at high rpm, after a good shotpeening. I've been told, and read, that the stock 4a was tested to 10k rpm continuous, even though they limit at 7.5k.

EDIT:
I left my glasses downstairs, and the pictures aren't that great, so I can't figure out which pistons, if any, have the ceramic coating that would indicate GZE. Also, Carillo used to build all the Group A rods for Toyota, but you'd be hard pressed to find a set, and be prepared to auction off your first born. I've seen the stock GZE MR2 rods handle 350hp on a twin-charged setup. I think you'll be fine. Save the $700 and buy some decent suspension.

04-09-2009, 02:19 AM	#6 (permalink)
CpuZapper RallyRacer Join Date: Mar 2005 Location: Portland, OR Posts: 480 Thanks: 7 Thanked 25 Times in 22 Posts My Google Map iTrader Rating: (1/100% )	Left is either a GZE or NA from an '87-'90. Right looks like a smallport GZE. And the middle could be a late model 16v NA smallport. They did make those with oil squirters, from 1990 on I believe. Though it is either missing a pin retaining clip, or it's one I don't recognize. I rambled, let me try to bring my thoughts together... IN THE US: The early 4a (technically up to 87ish, they built some using left over parts) had a 5 rib block, 40mm rod journal, and 18mm pressed in wrist pins. These are most easily identified by their lack of pin retainer clips, and their inability to be separated from the rod without a press. The later model motors - all 16v after as far as I can recall - used a 7 rib block 42mm rod journal, and 20mm floating pins, which require the retainer clips. The oil squirter blocks were available as both the small port NA used in a few cars, and the small port AE101/AE111 SC motors. I've seen factory built motors with 7 rib blocks, and older 40mm/18mm rotating assemblies though. There were also some changes to the oil pump over the years. I think that's right... it's been way too long since I had to remember all that. Anyways, almost all the rods, the blacktop 20v excluded, are pretty stout. Stock rods hold up rather well, even at high rpm, after a good shotpeening. I've been told, and read, that the stock 4a was tested to 10k rpm continuous, even though they limit at 7.5k. EDIT: I left my glasses downstairs, and the pictures aren't that great, so I can't figure out which pistons, if any, have the ceramic coating that would indicate GZE. Also, Carillo used to build all the Group A rods for Toyota, but you'd be hard pressed to find a set, and be prepared to auction off your first born. I've seen the stock GZE MR2 rods handle 350hp on a twin-charged setup. I think you'll be fine. Save the $700 and buy some decent suspension.