Ατμοσφαιρικη βελτιωση (English text)

[TOLIS EE80]

Hey all wrote this up about 4 months ago in word, never got around to finishing it as I lost my Rolla and interest for now tongue.gif
So I may as well post up what I had typed up even though it is not really finished
Might be of help to N.A 4age fans wink.gif


Matt’s Modified N.A 4AGE Page

For modifications to the GEN 1, 2 & 3 4AGE 16v
( TVIS Bigport’s and the Smallport )
First some basic back ground info for better understanding:

What is Camshaft duration & lift?

Camshaft lift is measured from the top of the base circle to the tip of the lobe. In this case, the lift is 7.1mm. This lift is generated over 116 degrees of cam-lobe duration. Since the cam spins at half crankshaft speed, you double the duration to come up with an advertised duration of 232 degrees.
If you have a 7.1mm lift cam this douse not mean your valves open up 7.1mm they actually open up less due to the Valve clearance that you set with the Shims.
Standard clearance is 0.15 to 0.25mm for the intake & 0.20 to 0.30mm for the exhaust
So if they’re set to 0.15mm your valve will open 6.95mm





The above drawing I based measurements on a standard Smallport cam shaft.
The Bigport camshaft is 240 duration & 7.56mm lift

Aftermarket performance camshafts are designed to open the valves more and for a longer period. When you build performance N.A engine’s you normally need to run a much higher RPM to make more power then the standard engine would make.
Performance Camshafts are designed to keep making the power at those higher rpms you need to run, though the downside of this is you loose your bottom end power.
So the bigger profile of the camshaft the higher the RPM range you make peak power at and the less bottom end you will have. Also the engine must be made to idle at a faster rpm. The bigger the cam the faster it must idle depending on the tune.
It would also determine how street able the engine would end up being.

Advancing and retarding Cam shafts what does it do?
To advance and retard your engines cam timing you would need to buy a set of adjustable cam gears, you could skip a tooth on the cam gears but this would be too much and affect the performance of the engine.
The Crankshaft does 720 degrees for 1 complete cycle, In that time the camshaft has done 360degrees
The 4age has an 18tooth crank gear to spin the 36tooth camshaft gears at ½ engine speed.
So 1 tooth on the cam gear is 10 degrees for the camshaft on the 4age 16v engine

Advancing your camshafts will move the standard power curve of the engine which would give you a low to midrange power
To do this you must rotate the cam gears in a clockwise direction.
Retarding the cams will do the opposite, give you more mid to top end power
To do this you must rotate the cam gears in an anti-clockwise direction.
Usually when buying performance cam shafts they come with a cam card that tells you at what degree the camshafts need to be dialed into.
Dialing in cams is when you place a degree wheel on the crank shaft and two dial indicators on the shims/lifters.
One for intake side and the other for exhaust side. This is so you can set the cams to exactly the right degree to start opening or closing the valves.
It is also a good for a third dial indicator down the spark plug hole if you can, so it can sit on the piston to check TDC and the degree wheel has not moved when your rotating the crank.
This is the cam card that came with my 270duration & 7.9mm lift cams
They are designed as a midrange camshaft and improved the torque of the engine much more then it gave power as the peek rpm they are designed for is near standard.

Reduced: 69% of original size [ 741 x 383 ] - Click to view full image


After installing these cams the engine became very responsive and peaked much faster then a standard 4age. The power Curve in result was much more aggressive. The only downside is I lost power under 4000rpm, and it idled very lumpy at 900rpm.

Engine Balancing:
Engine balancing is when we make the rotating and reciprocating mass the same weight so the engine spins more free and smooth,
For an example an unbalanced engine is like running as fast as you can with a brick stuck to one foot.
I wont go into it too much as it is not something that can really be done at home, Though if you are thinking about building a performance engine I would seriously recommend it getting done buy a professional.

3 angle valve seats!
3 angle valve seats in the 4age or any modern engine for that matter you will find is standard from factory.
The reason for this is so the air can flow past the seating aria more freely (More air into combustion chamber) then it would with just a 45 degree seat common on much older engines.
There are 5 angle seat cutters, so you can have 5 angle seats witch would be better again.
Facing valves!
Normally valve faces are ground to 45 degrees to match the seating aria to seal the ports off from the combustion chamber when valves are closed.
To improve the flow of the valves you can have a back cut ground above the face of about 20 degrees or so. Not sure how much difference this modification will make as I did not do it on my engine as my ports and valves where pretty much stock.
This pic I drew may help understanding.

Reduced: 82% of original size [ 620 x 370 ] - Click to view full image



Piston, Con Rod & Crank shaft terms:



Compression Ratios:
Compression ratio is the volume of a combustion chamber and cylinder, when the piston is at BDC and the volume when the piston is at TDC. The higher the compression ratio, the more mechanical energy an engine can squeeze from its air-fuel mixture. High ratios place increased oxygen and fuel molecules into a reduced space allowing for increased power at the moment of ignition.
This link is a quick calculator to work out your compression ratio.

http://www.csgnetwork.com/compcalc.html



Engine Power Calculator

HP = C.I. / 150.8 x RPM / 5252 x C.R x (14.7 + boost) x V.E.

C.I = Cubic Inch
RPM = The rpm in which it makes it’s max power
C.R = Compression ratio
V.E = Volumetric efficiency

V.E is a percentage so when you put it in the math formula if it is 99% you would put .99 if it is 102% you would put in 1.02

EG:
Workings for a Smallport 4AGE 16v
98/150.8x7200/5252x10.3x14.7x.99 = 133.5hp

Standard 4A-GE 16v Bigport VE = 1.02
Standard 4A-GE 16v Smallport VE = .99

Also bit of useful info, there is about 19.4kw Loss through a C52 gearbox and final drive in 3rd gear








Building a 4AGE 16v N.A engine

There are many different things you can do to a 4AGE 16v engine to make them perform better then standard. You may have cold air induction or a nice set of extractors installed for a little extra power (2-3kw maybe?), the real difference to be made is buy pulling the engine down and machining and replacing parts for performance items.
The first thing you could try is installing some small profile camshafts. They say that the biggest camshaft the standard ECU can take is around a 264 duration cam, when I installed a set of midrange 270’s the stock ECU could barely keep the engine running. So a piggy back computer had to be fitted to sort it out. Any bigger then a 270 duration cam and it would defiantly need to go to a complete aftermarket ECU.
As the cams I installed had an advertised power range of 3000rpm to 6500rpm they did not make much more power then the standard engine as the peek power was around the same RPM. What the cams did do to it is give it a bag full of torque.
To make a bit more power with that size cam you could give it more compression.
The late model 4age’s run around a 10.3:1 compression ratio.
To achieve more compression you could get the cylinder head face machined down to decrease combustion chamber CC. The standard 4AGE 16v combustion chamber CC is 38-39cc. Machining it down to a 36cc combustion chamber on a standard 4AGE 16v will leave you with a CR of around 10.8:1 , and an increased power over a standard 133.4hp 4age of 6hp (4.47kw) in theory.
So the only real way to improve the power is bigger cams. If your after more top end power I would recommend something around 290duration & 9mm lift as this cam would make power around 8000 – 8500 rpm. Though it would be a very good to install some aftermarket Valve springs that can take the 9mm lift without the spring coil binding. It would also have to be a stiffer spring so that it can take the rpm’s and close the valve in time before it reopens.

[TOLIS EE80]

This is a TRD copy valve spring that I used in my 4age on the left and the original 4age 16v valve spring on the right, as you can see the TRD copy valve spring will coil bind much later then the original one would and it is also a stiffer spring.

Reduced: 97% of original size [ 526 x 398 ] - Click to view full image


Using a lift as high as 9mm or over can turn into a disaster as the cam lobe can flick the shims out of the valve buckets, 9mm lift cams are boarder line so if I had a cam that size I would install some shim under buckets, This can be very expensive for what they are.
But apparently the Shim under buckets from a Toyota 1SZ-FE 1.0 liter 4 cylinder engine use a bucket that's compatible with the 4age 16v.
More info on this:

http://www.club4ag.com/faq%20and%20t...%20Tuning.html

With camshafts that size you would also defiantly need to run a higher compression of around 11:1 or better 11.5:1 though milling the head down heaps might not be a good as the valve to piston clearance will be much less due to the bigger lift and lower sitting head, So it is a good to use some aftermarket forged pistons with +dome to give the compression you need. They are also normally stronger pistons designed to take the extra HP & RPM.
Arias Pistons make a 4age 16v piston with a +Dome CC of 7.5cc and are listed that with stock head and gaskets it will give a 10.7:1 compression ratio. Though they are only made to suit bore size of 81.5mm (standard size is 81mm) so the engine block will have to be pulled down and bored out to that oversize. To bump it up a bit more you could use a TRD head gasket 0.5mm thick, this should give you around an 11.3:1 CR.
If you are willing to go that far it would be a good to replace your old worn out & most likely stretched rod bolts with some ARP ones. They are much stronger and can take more abuse from revs, though the big ends must be closed and honed back to size when you install new rod bolts.
Also if you are going to be revving the engine up to or over 8500rpm it would be good to have the bottom end balanced as the forged pistons will most likely be a different weight then the standard cast pistons and throw out the balance.
The Standard rods should take 9000rpm maximum with some ARP bolts so if your not going to rev the engine past that the standard rods should be fine as long as you have some ARP in them,
As you can see the Smallport 7 rib block rods (20mm pin, 42mm big-end) are very strong and are the same rods used in the 4AGZE supercharged engine.

Reduced: 65% of original size [ 776 x 568 ] - Click to view full image


Though if the rpm concerns you, you can have the side’s lynished to remove any stress points and then have the rods shotpeened as well.
If you really wanted to have a strong engine you could install a ARP head bolt stud kit and an ARP main cap (crankshaft main bearing cap) stud kit , Though with the main cap kit you should have it tunnel bored with the new studs fitted to ensure 100% alignment just like the rod bolts. Anything past 9000rpm you will defiantly need Aftermarket Forged rods.
There is also aftermarket 215mm Aluminium and Chrome Moly flywheels that weigh around 3.6kg available for the 4AGE but street driven engines with aggressive cams you may prefer the Lightweight Chrome-Moly flywheel because the lower weight of the Lightweight Aluminium may hamper idle at lower rpm running.
In my opinion if your going to go to the expense of getting forged pistons and rods you may as well build a 7AGE using the 1762cc 7AFE bottom end and get the Forged rods and pistons to suit that engine. If you bore that block out to an 81.5mm bore it becomes a 1782cc engine. You will have to use the 4AGE 16v crank timing gear and a longer timing belt as the 7A block is taller to take the extra stroke of 85.5mm, Porsche 924/944 belt has been rumored to fit. You will also need a custom exhaust manifold so it can have clearance under the sump if the engine is in a FWD car. The 7A also does not have oil squirters (piston coolers) like the Smallport 4age 16v (100kw engine) douse.
The 7A uses a 6 bolt fly wheel apposed to the 8 bolt 4age flywheel, The 7A 6 bolt can be made stronger using 3 solid steel dowel pins and some ARP replacement bolts.
One advantage with the 7A engine is due to the extra capacity you will not need to rev the engine out so much to make the same power as a 4AGE making power @ 9000rpm.
So you could probably get away with using some standard cast pistons and use a 82mm over size to increase the capacity to 1803cc and save $$ on forged pistons, I would still recommend replacing the rods with forged items as the standard 7A rods have a very narrow neck, they also use a 18mm press fit pin and would most likely brake after constantly seeing 8500rpm every day.
This is a standard 7A rod Vs a Forged item with a 20mm floating pin little end to suit the later 4AGE pitons. The big end is machined to suit the standard 7A crank size.



As you can see the 7 rib 4AGE block (painted orange) and the 7AFE block (bare) are nearly the same, just the 7A is taller to accommodate longer stroke, so you will need to use the 6-bolt 7A crank.
Both blocks are a standard 81mm bore.

Reduced: 99% of original size [ 515 x 714 ] - Click to view full image


If you are going to be running over a 11:1 compression ratio it is a good to not have any sharp points removed in the combustion chamber that will cause pre ignition due to hot spots.
As you can see in the pic below on the standard 4age (left) you can see an example of a hot spot. The pic on the left is an engine that would be running high compression and has had the spots taken away.

Reduced: 48% of original size [ 1055 x 408 ] - Click to view full image


While you’re playing around with that you may as well clean the ports up of any sand casting marks left from when the head was cast.
You can also open up under the valve a little bit but don’t go 2 crazy as you will loose power, its best just to keep to cleaning the ports out and putting nice round edges on things that have sharp turns.
If you’re planning to run up to a 272 you will fined the Smallport head with light port work is all that is needed. With 288’s I would start playing with throttle bodies.
A 290 cam or bigger it would probably be best to run a Bigport head and ported intake manifold with over size throttle body or run a Quad throttle body set up.

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