7afe vs 4age

[Caveman]

Hi

Im currently in the middle of a turbo project. I was just going to use a standard 4age block but now im leaning towards a 7afe block plus 4age head. The main problem I see is the bore vs stroke. The 4age is a large bore short stroke, good for high NA output (81x77), less strain on the crank and rings. The 7afe has a longer stroke than bore (81x85.5) which accounts for the extra cc's.

Would the extra high power with the longer stroke be ideal? In an ideal world I would prefer a square motor but unfortunatly my budget only allows me to run a rebuilt 4age or rebuilt 7afe. Are the cranks on the 7afe strong enough to take the extra load from a longer stroke? What about the rings? If I run the 7afe I will use the 4age head, computer and a vf10 expecting a moderate 140fwkw.

Also does anyone know the compression ratio of a 7afe block plus 16V 4age head? Im going to CC them anyway but if someone knows that gives me a bit more info.

Thanks

Any input is appreciated.

[ke_25]

try pm'ing mrxxx as he has built one of these..

[Mr Revhead]

actually i think it would be good if ppl that have experience can post it here.
i know several ppl including me are looking into this or similar and haveing it openly discussed would benifit more ppl.

fromt he research iv done stock rods and cranks are fine for the power you want with stock redline

[~SlideWays~]

actually i think it would be good if ppl that have experience can post it here.
i know several ppl including me are looking into this or similar and haveing it openly discussed would benifit more ppl.

fromt he research iv done stock rods and cranks are fine for the power you want with stock redline

2nd'd I would like to know as well. Lol im bound to blow up one of my gze's.

[JamesM]

i think it was glenn that built mrXXX's motor? or am i wrong.

[Grotty]

yep glenn built that 7a of mrxxx's, i know bazda is building one, so is glenn, i also have one kicking around.

[Mr Revhead]

well i think we need to look at a faq type thing.
how about info/opinions on:

what cambelt to use
what compression ratios does 16v/20v head give
what stock rods can/have handled
converting to 4ag/ze pistons
what ecu set ups. eg can a 20v ecu run a 20v 7age etc.

i know iv found a lot of conflicting reports, and i have a good idea of whats good and whats bad, but hearing ppls experiences would be handy.

[Mr XXX]

Yeap, my motor was built by glenn.

But heres a few things.

Basicly with a factory 7afe block with blue top head, the peak power is about the same at the same revs. The big advantage of the 7a, is the torque, it feels so diffrent to a 4-age, I love it. I have only just in the last week really started exploring the posibiltys of where this motor can go.
You have to remeber that in a simpl build, your running pretty lo compresion, I havnt check what it is running at yet.

Ecu wise im running a link, in all honestly, I would feel your probabl just wasting time using any stock ecu, the power gain can be huge by just this simple change. If you talk to the garage dori guys, they swear by a fuel ecu called mega squirt. Google it, there is a lot of support on the net for this ecu.

From what I have read, people wouldnt sugest aiming for more that 250whp on the factory 7afe rods.

Heres a tech article from http://www.club4ag.com, which would be one of the best places to start to learn about 7age,s there is alot of expericance there.
http://www.club4ag.com/faq%20and%20tech ... d%207A.htm

As for converting pistons to gze, its the same as any other age motor, as long as the gudgen pin is 20mm (I think) then they fit. I know grottys motor has gze pistons in it. Another thing with the piston is deciding what comprsion ratio's your after, gze's come in 8.9:1 and 8.0:1 (roughly). So if you want crazy boost then the lower compressions going to be better, but also a waste of time. Boost would come on like a light switch, due to the longer spool time of the turbo.

Also I nkwo there are a few guys in the us that are running these with factory cam wheels. Dont waste your time, timing on a motor can make all the diffrence. Adjustable cam gears are really a must.. Also ther are a few diffrent options for what belt to run with. And each type determinds which belt tensioner to use.

Any questions just ask and will try and answer, but like I said, hit the http://www.club4ag.com forum, and run a search on 7agte's, theres lots to read.

Look for the thrad by team66, hes got some good experiance
Allan
Mr XXX

[Mr Revhead]

yeah i try and stay away from club4ag, waaaaay to much incorrect info there.

7afe rods have a different gudgeon size so you need to mod the rods.
i was kinda hoping for some one who knows these things to do a bit of a write up

[Mr XXX]

haha fair enough. From what I understand there are two diffrent size gudgen pins in the 7afe range. Could be wrong.

[vvega]

lol last time i checked the pins were the same time
you also have to deal with negative deck hight

7agte's are so last yeah

bazda has my old one
though hes made it much better now


v

[dash]

you find "waaaaay to much incorrect info" here as you do club4ag and other forums.... keep a good bs filter handy.
I posted a link on club4ag where 2 brothers built a 7age and 7agte.
The 7age was a pretty simple build with interesting comments on what it did for the cars performance... hence why they built a turbo 7ag next.
A fairly detailed thread on toyomods also, not long before the switch

[vvega]

i think we can deal wit the bulshit considering between a few of teh members here weve built 6-7 of them now

i put much effort into finding the eaziest way to do it without buying a odd sized cam belt :d

v

[Mr Revhead]

yeah but the incorrect info here is in the form of posts in threads and is mostly corrected. in club4ag its in the form of tech articles.....

[vvega]

i have picutre of my build on clubaw
and bazzda has pics od what he did to finish the engine as well

v

[suberimakuri]

I'm sold on megasquirt.

[ezy10s]

This info is for a 16V head conversion only(i havent done a 20V so wont risk commenting on them)

Cambelt to use is from a Porshe 944 turbo Gates part number is T107.
you have to run adjustable cam gears to get the cam timing right.

the compression on MRXXX 7age is apporxiamately 8.1-1

gudgeon pins= if your going to run 4age pistons on the 7afe rods we found the easiest way to do this was to use the 7afe pins but put them in the lathe and skinny them up with a piece of emery cloth, pretty seat of the pants but worked fine. (you will see why we did this if you every actually get round to doing this conversion)

If you want to make an N/A one and intend putting the 4age pistons in remember that the compression will be higher than what the same pistons would be in a 4age. basically redtop pistons in a 7age situation willresult in something like 12.5 to 1 compression with a .8mm gasket.

grottys 7agte is this :
Standard crank and rods- modified 7a gudgeon pins
8.0-1 ze pistons
small port 16v head with the valve chambers enlarged and new firmer valve springs.
std acl head gasket
arp head studs
std 7afe flywheel
custom adjustable cam wheels
4age tensioner
Porshe 944 turbo cambelt
S13 ca18det T25 turbo
custom turbo manifold.

If he ever gets it into the Carina and going again we will get some dyno sheets up.
We originally had it in Nick teeboones ae86 drifter- only for one event as it wasnt his engine, and it went bloody well on 10psi.

[vvega]

if you use the blactop head you can use a bluetop cam belt
havent done a silvertop one

with 8:1 pistons and the blactop head it was worked out to be 7.5:1 c/r
i had a negative deck hight of .100"


v

[no_8wire]

http://autospeed.drive.com.au/cms/A_0666/article.html
20 valve turbocharged induction system.
The bottom end is a large 1.8 litre 7AF-E unit, which has specially been prepared with 4A-GZE oil cooled pistons, Argo custom rods and 3/8 inch ARP bolts.

The engine's static compression ratio is a generous 8.9:1

The 20 valver's flow is bolstered by the latest generation Garrett GT25 twin ball-bearing turbo, and a water-to-air intercooler is used -
Fuelling is left to an Autronic SMC computer, which fires four Celica turbo injectors.
18 psi will see it deliver a solid 300 horses at 7000 rpm

This is my goal...

[Mr Revhead]

thats more like it.
split and FAQ!


thanks guys