4AGE info, where to find?

[andylaurel]

but from a stroking perspective, there are the well known HKS 5AG cranks around but they aren't that easy to find these days...
you can do it with a 7AG conversion by buying a AE101 shape 7AFE motor (six bolt crank) and fit it with any G head from 4AGE. This doesnt increase the Bore but only the stroke and results in an oversquare motor thus decreasing its ability to rev.

edit: if you want i know a person who has a HKS 5AG for sale.

[Devils]

you my son, are on drugs

Maybe... maybe not! :-p

Ok so looks like keeping it stock in terms of stroke and just bore it out a mill or two should be about all i will need to do.

Anyone know the highest reliable static compression someone has taken these motors to? 11.5:1, 12:1???

[Talasas]

I think I've seen race motors using 13:1 CR pistons before...

[oldcorollas]

Anyone know the highest reliable static compression someone has taken these motors to? 11.5:1, 12:1???

what is the purpose of the engine?
what is the proposed powerband?
how long does it need to run at what revs?
what fuel will you be running?

[-GT-]

Go easy on him guys, he is from a nissan forum...

Only stirring. I think once you've been around here for a while you forget just how much technical knowledge is shared across this forum, we forget how lucky we are and that the Toyota fraternity is one of the more technically apt groups getting about. And friendliest.

Feel free to ask away (nicely) and there'll be plenty of people willing to help. A number of them have already posted here! And we wouldn't consider it a miracle that someone knew those specs on their favourite engine, or on a bunch of the more common ones around here. Hell, some may even know about things like fords too.

What info are you still chasing?

Edit: In regards to the squareness of the nissan mills, are the ones you're referring to perhaps undersquare, hence closer to square would make them more rev happy? As the 4age is oversquare, taking it back to square (and worsening the rod/stroke ratio) would make it much less inclined to rev.

[Devils]

oooooooh they are oversquare? Damn i read the info wrong... i thought it was 80something bore and 77 stroke!

Sorry fellas now i know why you were all scratching your heads wondering what i was on about!

As for what i'm building the motor for, just a bit of an all rounder. I like to play arround to find the perfect power band for the way i drive and the given car.

I've built two different CA18DET engines from scratch, both having completely different power bands. Then i moved onto an SR20DET, using a DE base adding on a turbo and playing around with turbo housings, timing, boost etc finding that this was more 'streetable' than the CA's i built but having a BETTER curve on the dyno.

I usually build to be streetable and track worthy. Never use anything less than 98 and where possible only ever use BP Ultimate.

I've always liked superchargers... but i've still got limited knowledge when it comes to them. So it will be a while before i start building a new engine for my baby.
The N/A model i had in UK was fun enough as is, so just having the extra power of the charger on this one i'm getting will be enough for now (even coming from a 2L Turbo).


EDIT: Ok now i'm confused... the bore IS 81 and stroke 77... So will there or will there not be any gain stroking it to 80-82mm?

[oldcorollas]

yup, the bore is bigger than stroke.
going to 82mm stroke will lose you 2.5mm of rod length (and a lot of bearing size, unless you find a 5AG crank.. but they might be 40mm jobbies anyway)
the rod ratio gets worse, you are moving the pistons further, so arguably you lose some max revs (but the 4A doesn't really need more anyway)

you will go from 1590cc to 1690cc = 6% more capacity.

plenty to do before you go that last 6% capacity.... you can get up around 300kw with turbo if you really want to....

then again... twinscrew would be fun in that case, a change from say 14.7psi to 16.5psi has the same effect as the stroking....

[takai]

yup, the bore is bigger than stroke.
going to 82mm stroke will lose you 2.5mm of rod length (and a lot of bearing size, unless you find a 5AG crank.. but they might be 40mm jobbies anyway)
the rod ratio gets worse, you are moving the pistons further, so arguably you lose some max revs (but the 4A doesn't really need more anyway)

you will go from 1590cc to 1690cc = 6% more capacity.

plenty to do before you go that last 6% capacity.... you can get up around 300kw with turbo if you really want to....

then again... twinscrew would be fun in that case, a change from say 14.7psi to 16.5psi has the same effect as the stroking....

Bah, you always need more revs. 9000 just isnt enough for the main straight. Really want 9500....

Listen to oldcorollas, he knows his stuff.

P.s. dont listen to me, im just a rev happy racer.

[oldcorollas]

i'd listen to takai first , at least he's built a 4AG

[Devils]

haha how about i listen to you both...

Gaining revs is just a matter of balancing an engine properly. I was confusing things by putting 'stroking' and 'rev happy' together. But lets put that aside.

I actually know a mob that can make a crank to spec so i would have just got one made up if there was going to be a large improvement.

I'm over turbos (for a while at least) and want to just concentrate on the supercharging side of things. Worst comes to worst i can always fit a vortech that i've got sat in the workshop!

So what do you think would be a better direction to take? Full light weight stock spec bottom end with a nice head, higher comp pistons?

[oldcorollas]

check out 30psi's members ride thread.. remove turbo, add twinscrew.

vortech would be horrible

[3sgte]

Apologies if I completely derail the thread, but an easy way to get an extra 400 cc is to swap the 4A for a 3SGE.

Thats what I did in my Corolla. It was very satisfying and far cheaper than any serious 4AG/7AG engine work would have been.

Edit:
In case the OP is unfamiliar, the 3SG option would require engine mount and other miscellaneous fabrication work.

[DigitalPho3nix]

haha how about i listen to you both...

Gaining revs is just a matter of balancing an engine properly. I was confusing things by putting 'stroking' and 'rev happy' together. But lets put that aside.

I actually know a mob that can make a crank to spec so i would have just got one made up if there was going to be a large improvement.

I'm over turbos (for a while at least) and want to just concentrate on the supercharging side of things. Worst comes to worst i can always fit a vortech that i've got sat in the workshop!

So what do you think would be a better direction to take? Full light weight stock spec bottom end with a nice head, higher comp pistons?

Hey mate welcome to Toymods!

In my experience there is ALOT you can do with the 4A before you touch the bottom end. I'd be spending the new crank money elsewhere first. And the only real gains you can make from a crank are from knife-edging it and taking some mass out.

- Start with your intake and exhaust.
- Get some nice cams made up. There are plenty of very good cam people here in WA.
- Programmable ECU. Motec is the business, and every good tuner knows how to tune with it.
- Look at lightening the bottom end (reducing reciprocating mass without compromising too much on strength is the goal)

Bear in mind these engines quickly become quite hostile in a street environment. You start to lose bottom end torque and mid-range power.

Or you could just supercharge/turbo the damn thing and have a much more streetable engine in 1/3 of the cost.

[DigitalPho3nix]

Apologies if I completely derail the thread, but an easy way to get an extra 400 cc is to swap the 4A for a 3SGE.

Thats what I did in my Corolla. It was very satisfying and far cheaper than any serious 4AG/7AG engine work would have been.

Edit:
In case the OP is unfamiliar, the 3SG option would require engine mount and other miscellaneous fabrication work.

You've got the right idea dude. You will probably need to look at your suspension afterwards though.

[Devils]

Hey thanks for the reply mate, i might have to grab those contacts off you for CAM work.

I'm not interested in going to a 3S otherwise i would have just bought a SW20 (which is cheaper anyway) but why on earth would i want to do that? *no offense to SW20 owners*.

Ok so the starting engine is a 4AGZE.

I've got a MoTeC M48 that i may use, otherwise i use Adaptronic ECUs.

I would probably do a similar build to one of my CA18DETs which was the following.

Crank was shotpeened, counterweights knife edged and whole thing race polished.
Forged lightweight rods, and forged light weight pistons. All full ballanced with a lightweight flywheel.
The block was over bored 1mm.
The block and head were "o-ringed".
Pistons were .5:1 more than stock items.
Normal 'modified' head gasket was used due to o-ringing the block.

Head was skimmed to bring the compression up another .5:1.
Ports were simply de-dagged.
All new valves and stiffer springs.
Slightly more aggressive cams.
Custom intake plenum.
Then all the usual performance bolt ons!