4age N/A tuning

[45aken]

die turbo....

ok, currently i am about 90% through a full ground up ae86 rebuild. from what started off as a simple engine conversion, has now turned into a everything at once kinda thing (too much stuff to list basically).

now what i was going to do was after the car was finished was thrash it around while building up a ~180kw ATW 4agte, then just drop it in when i was finished it. i was going to go the turbo route basically due to the fact i could get this power for ~$3000 (all done properly).

BUT, now i am looking at forgetting about the turbo, and going the N/A route, to about 180HP. i've done a bit of research, and what im planning on getting for the 4age (100kw 7 rib bottom end+big port head) that is in the car now is;

20V ITB's (found vacuum line fix)+T3 plate
around 288deg cams
adjustable cam gears
microtech

i know i will need more stuff than this, but this is all i can think of right now. im thinking like maybe high comp pistons etc. what about internals other than pistons, i heard the rod bolts are only good til about 170hp, and i want this motor to REV.
can anyone reccomend a good place in NSW to get the head ported/polished?

also reliability is a must, so if i do it, im going to do it right the first time around.
any help?

[slide86]

Here are a few things to think bout.....

- balance and blueprint of all rotating components
- ARP studs through out the engine
- lots of head porting
- oversize valves
- strong rods and piston pins.
- "sexual" extractors (meaning look and flow awesome)
- maybe even bigger cams, say 304 intake and 288 exhaust???
- good vavle springs

it will be important to have a bulletproof bottom end for max revs. those rods will be taking a bit of a breating at high revs. thats where the balance and blueprint comes in. decent rods are still a good idea tho.
i cant think of anything else at the moment....

[oldcorollas]

light pistons, lightest stock rods, lighter valves, etc..
thats how you decrease losses up high, and increase the life of things like rod bots.. by decreasing loading.
for example, Beams 3SGE and honduh S2000 motor... both went on diets to be able to rev high and last.
just a thought...

so.. how high do you want to rev and how long do you want it to last... both are a compromise. if you were to build a forula atlantic motor, their life is measured in hours. (a full season is how many hours of actual running? 30? 50hrs max? )

[takai]

Where do you want the 180hp to be?

[normo]

My 4age is NA
I run twin dellortos from a 2 litre alfa ($200 from ebay)
a redline inlet ($220)
a tube of epoxy to block injector holes
a jaycar high powered ignition and dizzy management (put it together yourself about $150) This handles the vacuum advance. No distributor fits the 4age with the vacuum advance working in the right direction( all dizzy's that fit will give you vacuum retard, believe me I know)
The result is awesome. The exhaust note from the twins side draft carbs is orgasmic.

[mc68]

Where do you want the 180hp to be?

id also like to ask this question

id imagin with 304 cams it wouldnt be making much grunt under 6500/7000

correct?

[takai]

I was actually talking at the fly or at the wheels.
At the wheels you are looking at a hell of a lot of work, and your power band will be more than the suck can ever define on the street.

[mc68]

ah, my mistake then

[roadsailing]

will a microtech support alpha-n tuning?

from what i have heard you will be able to get 288 degree cams to be reasonably streetable with a good ECU and a good tune amongst other things.

i'm thinking i want to go 288 inlet 272 exhaust, but i still need to do heaps more research (drooling on my levin and trueno bible doesnt count as research)

whats a "vacuum line fix"?

[mc68]

why do people want shorter duration exhaust cams?

honest question.

[roadsailing]

why would you want equal duration cam shafts? that question is just as valid.

why are exhaust ports smaller than inlet ports?

why do people put harder springs on the front than the rear of AE86s when from factory the rear springs are stiffer?

its all about balance, and to be honest i'm not entirely sure of the answer myself, but IIRC it gives you a wider power band. this is one of the things i need to research

oh yeah, lots of the 4AGEs in the levin and trueno bible have bigger inlet cams than exhaust.

[45aken]

the vacuum line fix that was discussed on another thread about the quads, regarding linking all the vacuum lines under the throttle's into 1 line, then running it through a small 'tank' and then finally through a regulator/restrictor. (it's late so i might have missed something). this gives you a stronger vacuum signal without pulses.

the 180hp mark was just a guesstimate at the motor.

i dont really want to build an atlantic motor here, just basically looking for what i can get out of it before the big money comes in (eg custom work done by 60yr old guys who have been building motors for 35years). im looking more for a setup with bolt on components rather than major custom work. something on along the lines of ITB's,cams+gears, ECU, port/polish, higher compression.

[Dimitri]

i think 180hp is "almost" realistic.. but i think instead of thinking about numbers though you need to think about how you want the car to drive.

after owning a few 4ag's/86's (big port, small port, 2 black tops..) i think i have a pretty good idea of what i want. ultimately i want a small port 16v. because i like the feel of the engine and the response. ontop of that i want an engine that does not flatten off after 6500/7000 rpm. i want it to keep pulling harder and harder almost all the way to 8000 rpm. what i do not want though is an engine with such a narrow power band that it will constanly fall off of its torque curve when shifting up.

if it can do this i will be happy. numbers dont really mean anything. one thing that should be part of any NA engine build up though is a short ratio for your diff. there is no point in raising you torque point with cams ect, and then never being able to use it

what i think ill need to do this is a simple rebuild of the short motor, using small port pistons, with about 10thou off the deck and maybe 30thou off the head. plus some type of thin HG. ive heard rumour a stock 7af head gasket is .8mm? can anyone confirm?

then in the head i will need some decent sized cams, but not huge. 272/8mm lift should just about do it. id like to go a little higher on the lift but not to the point where i need a shimless/shim under conversion. unfortunately i have no way of calculating at what point this is, and i think it is not just lift that governs this, but ramp rates aswell. ill do springs, vernier gears, and of course porting.

porting and valve cuts is one place it can get expensive. i have been offered before a full race engine port job for $800. this is an incredibly good price. this encludes a 3 angle valve seat cut on the intake, radius cut on the exhaust, and full porting/flow bench development encorperating the use of epoxy (for re shaping/resizing the ports for the maxium flow and velocity). this only come from continually hooking up the dudes some with good deals.

this part of the build i think i am most undecided on. i can either skimp slightly on the cams (crow i can get cheap through a mate who's work keeps a rocket industries account) and do the porting myself (i ie very little except for deshrouding, polished chambers, contouring the valve guides). or spend up on some names brand cams (tomei/toda/hks) and have the porting done profesionally. i am more inclidined to choose plan a, partially because im a cheapskate, but also because id like to see just how well a home job engine build can perform while just adhearing to the very basics.

ofcourse the engine will need throttles and some half decent headers. i have seen even the most basic headers make really impressive numbers though. but i will probably still get/make some super long primary style 4 into 1 headers if for the most part only for looks )

[sam-131]

100hp per 1lt is very doable with a nice build up just got get back to basic's

just gotta think back in the day they were making all this power by doing shit all ya gotta do is just go over and pay close attention to detail when building an engine !!!

the three c's
cams
carbs being your case efi (well mabe make it the two c's and 1 e)
compression
is the ground work for a atmo engine

"most" of what i've learn is for sb's and fiat's but an enigne is a engine

ok will start with the lightening

pro engine builders such as David Vizard/ Smokey Yunick say by removing 1kg of mass of the crank is the equivalent to removing 50kgs of the chassis thus by removing more weight from the crank you get less reciprocating weight and with its ability to throw off any oil that was on it

acording to a book i have just recently read by Smokey Yunick (well know for building small block chevs) this man put a perpex screen on the side of a sb to see what it was doing and i quote "there is an oil cloud that swirls around the crank at speed, migrating back and forth at random, rather like a candy floss machine at a fair" which is why i would have a hard long look in to bafflers and wingage trays for the sump just image what that oil is doing to the blance also the rest of the oil not doing what it should lubeing!

now with out blancing and lightening of rods,pistons and fly wheel it's like doing half a job

thats the hard part over now the easy part

compression

these figures have been set for carbs but with efi some say you can go up half a point or so ok
runing pump fuel it is best not to run compression above 10.5-.6ish:1 on carbs! other wise well run into problems with pinging and to compensate we'll need to retarding the dizzy thus said i have heard of people running 11.0:1 and having no problem just depends on the design of swalsh pad/head

update

head work

this is what makes or break an engine i carnt tell you enough on how much it shit's me that people think there king kong because there running 40psi threw there eninge but hey there onlying make 150hp but i am running 40psi it's gotta be good(most of the cars you see in fast 4's) . The achilles heal of the enigne is the head it's gotta be able to flow to surport your bottom end that said i am not to flash hot on 4a's but you can get away without going lager valves by looking into the cams higher lift and longer duration!

toyota's generally have nice flowing heads 4ages 16v or 20v should able to flow 160-180 with ! a set of half reasonable cams thats said why your at it i would also look into match porting intake/exhust manifolds

well the rest is even easyer

half decent exhust,extractors with a high quallity tune is the key to finishing off the engine then agen you may need to upgrade the fuel system or should i say upgrade the fuel system to hold double the expeted hp and you sure be able to hit if not be over your wanted power figure

or i could of writen half of this and just said go overkill on it and you'll be right

this engine would be very realiable were just tweaking it the way it should of been built just freeing it up abit life span of anywere between 1k to 400k all depens on how it's treated

[45aken]

good info here guys,
what would the life be on an engine like this?
and when using the cams, would a set of after market valve springs be a good choice?

dry sump?