ok guys ive got a ke38 p/van with a 4afte, thats a 4afe with a turbo fitted not a 4efte. any way i wana upgrade cause i no the 4afe has sh!t internals i got my hands on a 4age out of an ae82 i believe this is a big port motor?. and now to my question which is the best motor to turbo the big port the small port or the GZE also reasonings as to why they are better/different would be great thanks

 

Duggy

Duggy, just have to point out you're asking questions that are DEFINITELY all over the net and have been covered by many people many times.

 

You're likely to get flamed.

 

Anyway, I read bits and pieces in the past, I think you want a 7 Rib 4age block. Believe these were standard with the GZE's? I'll let a guru answer you though.

4agze would definatly be your best bet as it is factory set up for forced induction

 

However if you can't find one or cost is an issue then the 4age bigport with red & black writing on top would be the next best thing as they arent quite as strong internally but they do have the 7 rib block run a slightly lower compression factory so you can put a few psi in without too many issues

 

Compression ratios

 

4agze - 8.9:1

4age Bigport - 9.4:1

4age Smallport - 10:1

 

I hope that helps

oh ok well will gze pistons and rods fit in a big port and also its the motor with blue writing on the covers andTVIS on the intake what does this mean?

Edited July 22, 200818 yr by duggy

oh ok well will gze pistons and rods fit in a big port and also its the motor with blue writing on the covers andTVIS on the intake what does this mean?

Yes those pistons & rods will fit in and the blue writing on top means you have the first gen 4age which has the 3 rib block

Yes those pistons & rods will fit in and the blue writing on top means you have the first gen 4age which has the 3 rib block

Be careful though, I'm not quite sure exactly if it effects the rods (but I'm pretty sure it does), but the blue tops have a smaller crank in them (I think its 40mm), now almost all GZE's run if I remember correctly run a 44mm crank. The only possible exception may be the first gen bigport GZE out of an MR2, but I have a feeling it too has the larger crank.

 

Arguably it is said that the first gen 4AGZE is the best for turbocharging as they run a lower compression ratio and have larger ports, but I don't think it'd make a massive amount of difference.

it all depends on what you want to do/how much you want to spend/how easy you want it to be.

 

since you already have a bluetop we'll start there.

hang on to the cams, they are better than all the other 16v 4ages.

 

You will need to get another crank as it is different (any 4age).

you will also need silvertop rods or 4agze rods.

 

your block is only 3 rib so high power will mean you should probably source something from the higher generations.

from the small port up they had oil squirters in the block also to help with cooling.

 

pistons from the 4agze will also be required. have seen these used as high as 22psi, came factory to handle 14psi and should see 18psi pretty comfortably.

they come in either 8.0:1 or 8.9:1 8.9:1 are still quite drivable. have even seen 9.4:1 Blue/red top ones used comfortable and 10.5:1?(silvertop) ones used on a really goos tune (I personally wouldnt though)

8.9:1 also provisioned notches for oilsquirters

 

a tidy 4agze would be the easiest as you can just bolt on the turbo and away you go. I'd be inclined to rebuild it though for reliability which would make the 4agze too expensive for something i could have rebuilt from parts of a 4age.

 

personally my ideal setup would be go get a small port, rebuild the internals with silvertop rods 8.9:1 pistons, keep the smallport head, run bluetop cams, new ecu, and prob a TD04 or 05 , T3/4 , or vf22? all fairly similar sizes, tried and tested.

 

This is just what I have come across in my experience, not a definative list. I'm not an expert, just sharing what Ive seen

 

-O

Edited July 23, 200818 yr by original

Buy a Silvertop, sell the head and quads, fit forged low comp 16v pistons. install the bigport head. Boost its guts out. This will get you the same rods as a later gze, same crank too, also a 7 rip block with the bigger small and bigend bearing sizes. The most expensive thing is the pistons probably, but then it will definately be tougher.

 

The 16v 4ages are heaps easier to turbo than a 20valve which has real issues with fitting a manifold over the quads and needs a compression ratio drop.

 

Specs of motors reported here:

 

http://www.billzilla.org/4agstock.htm

 

Google brings up that link with most searches relating to 4ages.