20v to 16v conversion

[meadan]

Car - ae86

motor - 4age

use - driving

problem - brain fart

personal situation (if applicable)- slightly cold


Hey,

I was just going over what parts I will need to buy over the next few weeks for my engine conversion and had a massive brain fart.
I currently have a silvertop 4age in my ae86, and want to change to a 16v smallport.
At the moment, Im running a microtech, so the 20v has coilpacks and rwd CAS cover. Im not using the ISCV or any standard gauges at all.

Should I be able to pretty much swap the engines over and just swap it all over to the 16v? Ill be running the itbs on it too, so injectors and everything will be swapped over, Im just not sure about the CAS.

[Sam-Q]

providing the length is ok for the crank angle sensor and the tps being held on the other side then you should be fine. However the wiring of the crank angle sensor might be different, the plug would be at the very least.

You can use the same coilpacks and all as the height is pretty good on a 16V, I had planned for a while to make an adapter plate however I am unsure if I will go through with it.

[meadan]

Im not so concerned with extending wiring and swapping plugs over.

Im mainly not sure about being able to make it run off the current microtech settings. Is the 20v CAS able to be swapped into the 16v? Or would I be better getting gze one?
I think the crank angle sensor is the only difference between the 2 engines I can forsee.

[Stain]

The 20v CAS won't go into a 16v... you NEED the one off the GZE if you're going to keep coilpack ignition.
Also the injectors are different. Can't use 20v ones in the 16v.

Other than that it should all be pretty straight forward depending on the 20v water system was setup.
But there will no doubt be changes required in the ECU, doubt it'll run with exactly the same settings.

[meadan]

Ah ok, yeah I guess will source a gze CAS then.

I will be running the 20v itbs, so the 20v injectors should work though?

I might be missing the whole point you are all making, but I was hoping I could pretty much swap most stuff over and let the computer think it was running the same engine and then get it retuned after its running.

But it might be easier to use the 16v loom and hook that up to the computer now. Would there be any differences in the microtech itself for the 20v and 16v, or can I just get it retuned to suit after its all in?

The water system will be redone, its mainly the computer and electrical signal side of things which im not sure about.

[slydar]

you will just be able to use the stock small port dizzy, internally (as in the CAS) its the same. a GZE cas would be neater but its not necessary. injectors will be your problem. the 20v ones wont fit the 16v rail. 20v is side feed smallport is top feed. if you search the internet/maybe toymods you may find a chart which has a list of toyota injectors. if you can find an injector with the same impedance/CC's that is top feed (even if the cc's are out of 10 to maybe 20%) it will work.

[slydar]

so yes your theory will work you just need to get the right injectors.

[meadan]

Oh now thats good news.

Yeah I was hoping to use the smallport dizzy, and then make up a cover similar to the rwd 20v ones to get rid of the dizzy cap, and just use it as a CAS.

If I swap the entire 20v itb setup onto the 16v, wont I be able to keep it all exactly the same i.e. injectors, tps etc
I thought this would keep the stock 20v fuel rail and associated bits?
The only thing I will really be changing is the bare engine from 20v to 16v.

[Stain]

the heads are too different. you can't bolt the 20v manifold onto a 16v.
to use itbs on the 16v you need aftermarket adapter plate (like the T3 one) to attach the quads to the 16v head.

[meadan]

Yep quite aware of that.

After some more searching, it looks like it should all work out ok. 20v dizzy, smallport dizzy, gze CAS all seem to be the exact same inside.
So ill just use the stock smallport dizzy as a CAS and make a cover (similar to the rwd 20v one) so it looks neater.
Ill use everything else straight off the 20v, sensors, tps, injectors, itbs, the computer wont even know ive changed the engine.

http://www.toymods.org.au/forums/showthread.php?12156-haltech-smallport-4age-CAS

Only thing I need to get rid of is the vvt wiring, though I dont think its hooked up to the microtech anyway.

Thanks for the help guys

[Stain]

You're missing the point that you can't use the 20v injectors.... the 20v manifold incorporates the fuel rail and uses side feed injectors.
the 20v manifold is thrown out in the conversion, it's not used at all. That's why you have to use a aftermarket adapter for the quads -> 16v head.
That means you have to use the 16v fuel rail and injectors (top feed) to suit.
But as Dimitri says as long as you get top feed injectors that are a similar (flow/cc) to what your using now the tune won't need to be altered.

[meadan]

Now that makes a bit more sense. I probably should have gone outside and had a look before replying, I assumed the manifold bolts to the adaptor.

But either way thats ok, Ill be getting the 16v injectors and wiring with the engine anyway, so ill have something to work with until I upgrade and figure the rest of the engine out. Plus it will definately be getting retuned.

[Vance]

its funny what youre planning on doing cause if we did end up swapping its exactly what i was going to do. smallport 16v with itbs

i have no extra input. everything i know on the subject has already been covered.

good luck man and i hope it ends up well.

[Anthony]

7MGE or 1GGTE injectors should be about right.

[slydar]

7MGE or 1GGTE injectors should be about right.

there you go. 7mge super easy to get at any self serve wrecker for just about nothing.

[meadan]

Yep sounds like its pretty sorted then. Im actually getting the complete running car with the 16v now, so Ill have more than enough to go off.
7mge injectors I already have some laying around I think.

Thanks for your help guys.

Also Riojin, cheers. I think great minds think alike, your fc is exactly what Ive wanted for ages. I just cant let go of the sprinter for some reason though.

[Vance]

the fc is exactly what i wanted when i wanted power. now that itch has been scratched and turned into a sore i dont like power anymore. stick with youre ae86 and never look back

[Stain]

I'm still having trouble grasping why you're going from a 20v to a 16v in the first place?

[ke_70]

im haveing trouble trying to work out why you cant use standed injectors? do quads require and upgrade here?

[Stain]

Under normal circumstances standard 16v injectors (182cc BP / 235cc SP) are fine. But a 20v has larger injectors (295cc) so for meadan to be able to use the same tune in his ECU he needs equivalent flow rated injectors for the 16v.

[slydar]

I'm still having trouble grasping why you're going from a 20v to a 16v in the first place?

there is plenty of literature and theory to support the small port 16v head being at least a match for the 20v in terms of potential.

its a somewhat complex argument, with a lot of variables. though it is commonly accepted that 4 valves/cylinder is the way to go.

there are other variables with the actual engine obviously like port/vavle angle, standard CR, ability to find a suitable low k donor engine, standard accessories (i.e manifold/throttles). also other outside factors like base car, level of "defectability" youre willing to settle with etc.

stock block 20v is the go $/hp.

mild tuned probably still 20v.

simple 7ag set up.. 20v is still probably the best engine to base it on.

all out NA build, definitely a blurred line. would depend a lot on your engine builder, and any inside information you could gather from people who have legitimately gone that far.

basically there are a decent number of 220hp+ 16v 4age race engine builds out there that have been quantified and documented.

20v's to me (although ill admit i havent been paying a lot of attention lately) are still a bit mysterious. obviously in this country Yager is said to have built engine of this caliber, and im sure he has. but no actual solid power figures are ever quoted, nor are $ figures required to get there, though it is certainly solidly 5 figures. im sure its been done but from what i can tell theres a few tricks to it.. which seem pretty difficult to decipher if youre not a paying customer.