the 7AGE thread

[Delazy]

we need one, so i started one....discuss

if anyone wants to copy and paste the posts from the original ae86dc thread, please feel free...i cbf

*sticky*???

[slydar]

http://www.ae86drivingclub.com.au/dcimages/1/8/546485.jpg

http://www.ae86drivingclub.com.au/dcimages/1/8/4141.jpg

http://www.ae86drivingclub.com.au/dcimages/1/8/4142.jpg

[slydar]

this is a reply on my thread on toymods from some one asking what part of the rod usually fails, and under what conditions.

http://www.toymods.net/forums/showthread.php?t=6751


Thread pulled out on all the one's I've had, and I have run a season and a half with standard rods, bored out with the floating pins, and yes precision is a must... but I have also run the inference setup too. We went to A/M cause I didn't feel there was a need to spend $$$ every year or spend every second season on the sideline half way through+ even more $$$$... it was Better spent doing it right first time (should say second ;) ) but then again the engine was spending all day, every day on the higher side of 7,300-7,500 and the fatal nail was a missed gear seeing it soar to around 9K :eek:, not once but on a third oops on the same corner.... I will admit I would of liked some oil squirters there and they can always be install afterwards with a bit of thought and most likely trail and error.

[redsprinter]

http://www.ae86drivingclub.com.au/forums/showthread.php?t=1308

heres a thread i started last week. for all the guys who would like a basic DIY 7age .

[slydar]

comparisons.

rod length 4a 122 7a 132.5
little end 4a 18(late ge 20) 7a 20

7a deck height is an extra 15.4mm

"crank radius" 4a 38.5, 7a 42.75.

4A
-bore: 81.0 stroke: 77.0

7A-FE :
-bore: 81.0 stroke: 85.5

rod ratio

4a 1.58

7a 1.55

difference in rod length 10.5mm
difference in "crank radius" 4.25mm

total of 14.75mm. deck height difference as listed is 15.4mm.

so it should be noted, there is a difference is compression height of 0.65mm.

this is important to consider when calculating/selecting compression ratios. it can be accounted for by using thinner HG's. the reason for the discrepancy is most likely because the 7afe uses a metal hg standard, apparently .8mm, but certainly thinner than a 4a one.

also important to note, is the extra capacity of the 7a will give you a higher cr anyway, when using 4age pistons.

if i were building an NA motor, id still have the block deck machined 0.65mm anyway. as this is clearly possible/safe. no chance of piston/head interference, or rings popping out of the block.

[fantapants]

soooo much love....

[slydar]

for the 7a, yes. it is win. i will probably build one this year. theyre turning up more and more at the wreckers. missed on just the other week. would have cost me $120 or so.

[slydar]

bump. why not.

[sun_moon]

any idea on how much to pay at a wreckers for a 7afe bottom end ??

[slydar]

they wont ever sell you a bottom end. it will be a full motor.

the going rate used to be $600-$700, but they have started to come down at some places if you look around.

[Chrisso]

pick and pay (or something along those lines) at campbell have specials all the time. Look out for their engine special, it's $50 for a bare engine. I bought my first bigport there for $50 about 2 years ago. They have a website which is handy.

[Mr Fujiwara]

what kind of compressions are we looking at with Ae92 pistons with a bigport head?
much the same?

[Vance]

pick and pay (or something along those lines) at campbell have specials all the time. Look out for their engine special, it's $50 for a bare engine. I bought my first bigport there for $50 about 2 years ago. They have a website which is handy.

got a link to this website?

[sun_moon]

what kind of compressions are we looking at with Ae92 pistons with a bigport head?
much the same?

the extra capacity of the 1.8 will bump up compression ratio... although im not sure on an exact figure, it will be 11:1+ i am guessing... good good. :cool:

thanks for the info about engine prices guys.

there seems not a lot of definete (spelling) information here on ae86dc about 7ages. for example so many are unsure of which timing belts to use with which heads and water pumps etc. and many more unsure things. lets try to cover all of them ^^

[Sprinter86]

DrifTE72 just bought a late model 7AFE bottom end from centre road wreckers, $70. he pulled it from a complete car and just pulled the engine out, and head off.

its not common that they let u do this though, i spose from a self serve they prob wont know till u drop the block on the counter :P

[slydar]

yeah. you could do that if the yard was big enough. the very cheapest you will get one for is $140 for a u-pull-it. then $60 back if you have another motor to return for "core return".

but they dont always have 7a's. infact they rarely do. theres another yard that often does have them, and youd pay 3/400.

[sun_moon]

3 to 400 is not bad still.

are custom rods essential ?? there is so so much conflicting information -__-;;

also wondering different build prices for different set ups.

im thinking of a budget upgrade for the stupid AFM bigport in my aw11. lol.

[*urban_ninja*]

average price for a 7afe engin i found was 400 to 750 but most were reconditioned. use the water pump and all other stuff off ya 4a head and a set of adgustable cam gears is ya basick set up that i understood. use ya small port pistons with 4a hd gasket will bump up your compression to win ratio. there is a bit of trial and error to be done im gessing but in the end i think it is verry worth while.

[sun_moon]

torque peaks at 2800rpm on a 7afe... cool.

any thoughts on the powerband of 7ages compared to 4age. plz discuss.

yes 4age HG is a must... the 7a HG makes a crazy comp ratio.

urban ninja, is ajustable cam gears a must, or is it to alter the power band to be better suited ??

[*urban_ninja*]

not a must but from what i have read and understood its deff a prefered just to help get it dialed in so your not wasting your time for the extra $200 or so its deff something i will be doing.

[wide s13]

also there is a 7afe with a crank angle sensor 2 that some people may be interested in using? i believe its american but ring brisbane motor imports thats were mine came from

[sun_moon]

can anybody give spec on there 7ages they have built with details etc plz. thanks gais

[NIZLAH]

Wtf is with this thread when there is already another more comprehensive thread 2 pages back on the exact same shit....

http://www.ae86drivingclub.com.au/forums/showthread.php?t=1308

????????:rolleyes:

[*urban_ninja*]

he wants to clean it out get all the info and keep it all as a sticky makes life easyerrrrr.....

[NIZLAH]

ahh.. fair enough then..

[Delazy]

Wtf is with this thread when there is already another more comprehensive thread 2 pages back on the exact same shit....

http://www.ae86drivingclub.com.au/forums/showthread.php?t=1308

????????:rolleyes:

check the time and dates the threads were made and the posts in them...the original thread u linked was only a very basic build recipe...this thread was to be a more comprehensive/informative thread...but it dropped down a few pages and everyone used the other one instead...

either way, doesnt bother me...ive got all the information i need for now

[shift_rook]

yeah as sprinter 86 said i got my bottom end for $80, i found it amusing cause i wrecked pretty much everything apart from the block in that engine bay, ruined the head as i had to snap some bolts off and cut every single cable so yeah i probably ruined like a few $$$ worth of stuff but meh, i got what i want and best of all it's from an ae101 and it's only done 25,000 i'm stoked, i'll do a full write up on how i go, i will be using a blacktop head with silvertop pistons and trd head gasket, suppoedly should have around a 12:1 compression ration but i'll work it out exactly when i get my head

[NIZLAH]

check the time and dates the threads were made and the posts in them...the original thread u linked was only a very basic build recipe...this thread was to be a more comprehensive/informative thread...but it dropped down a few pages and everyone used the other one instead...

either way, doesnt bother me...ive got all the information i need for now

Like I said, fair enough.... I'm not upset or anything, just found it strange to why there was 2 threads about the same subject going on and that the other one was 6 pages or whatever, this just looked like a fresh thread with all the same shit about to be said again..... didn't realise this one was started before the other lol...
all good, on with the 7age specifics....

[Mr Fujiwara]

GZE forgies with a 7A headgasket = good compression?

Does a 4a-c/7afe (6 bolt) flywheel bolt up to a 4age clutch (8 bolt)? ive got a good clutch thats why im asking.