Engine 4age head

4age head

So here's the deal. I was planning on doing a 4age/5spd swap this summer and the works. Unfortunately other financial problems arose (namely economically priced college :sad. Anyway, I was pondering what I could do to my car(daily driver) to make it a little more peppy. I've heard of 7age's being built but like I said I don't have the time or money to do that now. But what I was wondering is if I could throw a 4age head onto my 7afe and also run itb's without any other major modifications. I'm guessing some wiring mods might have to be done but other than that, is it possible? Would it be about as simple as putting the new head on and running the itb's with velocity stacks? or am i getting ahead of myself?

what you descibed IS a 7age

and a new timming belt from some porsche I don't remember

it won't run quite right, but it will probably run on the stock ecu.... you will need larger injectors and a very difficult to find distributor....

I thought a 7age was changing the pistons (compression ratio)


What would I need to do to make it run right?

a 7age is a 4age head on a 7afe block. You get the better flowing performance oriented "G" head combined with the extra .2L of displacement from the 7A block. It's not that hard to do, it's a straight bolt on process, you need to run a porsche 944 timing belt but you need to run a aftermarket ecu or piggyback.

microtech works great. , are you using the factory TVIS?

and no , 7age is a 7a block w/ a "G" head. you could change the pistons out if youd like but itd still be a "7a" block no matter what.

damn jspex me and you are hitting the same threads at the same time , everytime i go to answer you beat me , and post the same thing i do.

w00t

how much would something like that cost

depends on the build, your abilities, what you start with, and what you want to do....

For instance....

If you start with having a 4age (4afe in the car).... very basic
Have your ecu modified (if you know someone who can) can be as little as $1
Hard to find dizzy is going to be tricky to find, but possibly find it for $50
7a block could be as cheap as $50, use all stock parts (will make less power)
Gaskets, fluids, belts, and time

If you start with having a 7afe and need to source 4age parts... very basic
Have your ecu modified
Hard to find dizzy
4age head can be found with accessories for around $100 easily (if not cheaper, depending on contacts)
Gaskets, fluids, belts, and time


My setup thus far....
7afe block: $60 (has spun bearing... long story, I sourced a good crank and rods for $70)
new high comp 4age pistons (making 11:1 in a 7age $80
new high comp 4age rings (not the same as bigport rings $75
New ACL bearings & thrust washer: $50 shipped
New oil pump: $70 shipped
Machine shop work: $50
Gasket: have spares
Head & accessories: have spares
Belts: ~$40
Megasquirt 1 v3.0: ~$150
Relay Board: $60

I am debating adjustable cam gears.... I'm running a smallport head with stock valvetrain but new stem seals.... will go into my 87 t-top MR2 when all is done.... the first build of this ended in a spun bearing (block had 200K on it and nobody in town can turn a crank) in the ae92, but ran just fine on the stock 4afe ecu & electronics (modified rev range, though)

**edit** getting adj. timing gears as well... person getting the crank and rods from has a set.... straight trade for a spare JDM bigport LB I have lying around for the 7a parts and the timing gears....

again, only proves what you have, know, and who you know and what they have & want.

why not use the bigport bluetop , just wondering?

larger doesn't always mean better.... the displacement increase isn't that much, and if I feel the need for more breathing power I will just install bigport cams into it (or go with something mild like a 272).

I don't like t-vis that much plus I don't want to deal with the hassle of wiring the t-vis into megasquirt..... yes I could get an adapter plate but don't think it would help in terms of power, or could us the bigport manifold and no plate in there, but then would need a custom gasket as the 8 vs. 4 holes don't quite match up right.

The smaller un-obstructed ports on the smallport actually allow for higher velocity, which in my mind would mean that with the smaller cams I would believe to be around the same flow of the bigport head.

On top of all that, I have more spare smallport parts than bigport parts.... my only spare bigport complete LB is going to a friend (as trade).... I also have a spare smallport (complete, needs bearings and an oil pump), 3 spare smallport intake manifolds, and an additional spare smallport head (in addition to the head for the 7ag build)... I only have 2 bigport spare heads (one on the mockup motor) and one spare bigport manifold (new map manifold doesn't count).

willing to sell one of the 55mm throttle bodies off of one of those?

I never noticed a difference between the bigport and smallport TB's... I would have to look.... IIRC I actually have more bigport TB's than smallport.... only because the bigport manifolds I had in the past I pulled the tb's from..... when I was originally building my 4agte (which is a long story, parts are all in boxes now) I had modified a bigport TB to work at 90* from stock, and it was bolted onto a smallport.... but I dont recall a size difference.... but, never cared to look either.... let me see what I have and I'll let you know.

What would I have to do to be able to use the stock wiring and ECU? So its as simple as getting the 4age head, porsche timing belt and bolting it together? Seems too simple.

i dont know if there is a difference , between bp and sp , but 4agze tb is 50mm where as the bp tb is 55mm , and then the 3s is 60mm and the 7m is 70mm . i am full of useless knowledge like this.

this is not all your full of.:ninjastea

heres to ya alan:

both BP and SP have the same size throttle bodies....

I have one I'll sell cheap since I will probalby never use it.... it has a broken TPS and a large knick/small chunk out of the very edge of where the tube/filter would attach (smaller than pinky nail sized).... $5 plus shipping....

from a smallport, so it's setup for FWD cables

cool , ill shoot you a PM soon

before you send any money let me get a photo if it... the knick is a bit bigger than I remember....