Now to be FXGTT 20v turbo eventually...

[AE85.6]

7age AE86 !!! i bet its alot of fun, i have a AE85.5 with a 4age which i want to look at possibly replacing later this year as soon as everything else is up to scratch first, i was thinking maybe a ze transplant cause i think with a bit more tourqe these cars are evil, but a 7age is an interesting idea or 7agze or similar,

[ezy10s]

7age definately the way to- little bit of messin round setting up the timing- nothing too major. and as long as you dont get carried away with rebuilding the bottom end there is no reason you cant have it built and in the car in a day.

[ezy10s]

that sounds all good - shouldnt be any real dramas at all

[AE85.6]

so 7afe complete bottom end and complete 4agze head, anything else needed ? also what ecu are you running a ze one or ? did you buy the bottom end as is or did you start off with a complete motor ? just trying to sus what would be the easiest way to build one of these cause the gtz engine idea is all good but some of them are starting to fetch fairly hefty prices ay

trying to work out bang for buck thats all

[Fuct Munkey]

haha, before my post gets totally taken over alrite, i know acl do forged pistons for the 20v, they are listed as suitiable for the turbo conversion (i work at repco, so its not quite as pricey as it sounds), BUT wat i wanna know is if anyone knows if they have a dish in them to lower compression, being that they are designed for turbo, or if i still have to run a thicker head gasket...? being all the holidays i cant call acl till wed, was hoping someone mite know b4 then. che

[ezy10s]

i spoke to a guy ages back when they first started bringin those forgies in about this and there are definately two types of pistons they have . one being the 16v units and the other for 20v's .
From memory both the 16v and 20v sets had the same compression;
8.5-1.
if you call any appco or repco or who ever you plan to order them through they should be able to tell you from the book. O r at the least call the distributor (ACL) and get a definate answer on them.
If you do get stuck lemme know and i hit up my guy for the specs on them again

[kingcorolla]

just let ya know, 7a-fe's are also in corona premio's, i remember.

anyone know spec's of these engines? in particular, the big-end journal sizes? im thinking maybe 4a rods/pistons fitting on 'extra throw' 7a crank? Im doubting they do, as im guessing you would of tryed that beforehand, ezy10s.

Fuct-Monkey, ill apologize on behalf of us 4age heads, 7a's are an intriguing idea, especially when you add boost!

mmmmmm 200cc extra

[ezy10s]

the 7a rod is approx 10mm longer than the 4a rod- there really is no way of using them together- i tried to sust it out when i had my atlantic rods! big suxOr for me .
the journal sizes are the same its just the length- way too much.
and its impossible to put a 7a crank into a 4a block also as by thetime you finished relieving the block to clearance it there wouldnt be any bottom end of the block left.

[ChaosAD]

I heard that either the rods or crank (cant remember which it was) is quite fragile and couldnt be revved too hard. But that would probably be less of a problem with boost.

[AE85.6]

ye apologies Fuct Munkey for half taking over ya post, but as kingcorolla said its a interesting concept for sure,

so by making a 7age wouldnt it have more tourqe beacause of 7a bottom but still rev fast cause of the 4age head but have a lower red line ? i spose the 7as red line at 7 or something so wouldnt you have to rev then a little lower and with forced induction wouldnt this stress things more ?

[Mr Revhead]

those acl pistons are not the cheapest around.......
why not use 4agze ones? the valve cut outs dont come into it.

[EVLGTZ]

those acl pistons are not the cheapest around.......
why not use 4agze ones? the valve cut outs dont come into it.

sometimes they aint available at short notice hehe

We had to use the ACL ones and yep bit more costly but hey ya take what ya can get when ya aint got much time

[Mr Revhead]

yeah thats true.

im gunna see what i can do about that......

[Fuct Munkey]

the acl 20v forged pistons are lower compression, they drop it to 8.5 (same as gze) they have a -3cc dish for anyone who is interested. yea, it depends how cheap u really think im getting them for, and how cheap i could get gze pistons just toying with ideas at this stage.

[vvega]

ye apologies Fuct Munkey for half taking over ya post, but as kingcorolla said its a interesting concept for sure,

so by making a 7age wouldnt it have more tourqe beacause of 7a bottom but still rev fast cause of the 4age head but have a lower red line ? i spose the 7as red line at 7 or something so wouldnt you have to rev then a little lower and with forced induction wouldnt this stress things more ?

the rule of thum is that until you reach about 14psi of pressure(dpending on static ratio) the top of the exhaust stroke is still the most stress your rods/pistons see bar detanation
after 14 psi the bottom of the power stroke is the higher stress point

so whilist you do see more stress overall (@ 14 psi you get twice the peak stress per complete cycle)

your peak level of applied tenson on the rods is no more than the n/a application at presure under 14psi

also remeber that whilst the 7 rods are thinner they are also longer and longer rods are under less stress than a shorter rod givin the same power output dynamics

so simply put a longer thinner rod is as strong as a shorter thicker rod
if correctly proprtioned

please remeber this is a guide and not the same exact figgures for every engine
though +- 10% would cover variation

v

[vvega]

the acl 20v forged pistons are lower compression, they drop it to 8.5 (same as gze) they have a -3cc dish for anyone who is interested. yea, it depends how cheap u really think im getting them for, and how cheap i could get gze pistons just toying with ideas at this stage.

i got my set for $700 for the race series 8.5:1
over 500 for a set of gze
and yes i know what you get them for

v

[ChaosAD]

the acl 20v forged pistons are lower compression, they drop it to 8.5 (same as gze) they have a -3cc dish for anyone who is interested. yea, it depends how cheap u really think im getting them for, and how cheap i could get gze pistons just toying with ideas at this stage.

Weird, I cc'd my 9.5:1 red/blacktop pistons at -5cc.
Did that using a 1cc syringe, a piece of clear plastic and motor oil.

[Mr Revhead]

dont forget that price for the toyota ones includes rings