4age confusion

[rice]

how is it.......that this 4age engine which comes around 110-130 hp stock can produce over 200+ hp all motor with no forced induction?? i mean...why cant i do that on my 7afe corolla? i saw somewhere on t.v this dude with a 4age had close to 250 whp with no forced induction, how is the 4age doing this? whats so special about it? i mean....why does it respond so well to modifications?? thank u thank u

[Flashmn]

Well you could actually.
Making 200hp requires alot of work, even on the 4A-GE, and having it streetable as a 200+hp naturally aspirated engine is gonna have lot of issues. First of all you'd have to have cams that make power at very high revs, 7000-10000rpm or so. The powerband will be very narrow = not so nice on the street. Next the flywheel, crank and internals would have to be lightened, also gives some hassles in street driving. Forged high compression pistons are also needed, so you wont be able to run on anything below 98octane.

The nice part of the 4A-GE is the head, but its not so great as its made to be, honda B16 flows better stock vs stock, 4A-FE doesnt flow that much worse, plus the 4A-FE head has a better platform for head modifications, due to the runner shape and orientation, they're easier to work to better flow.

But 200hp isnt really impossible to make out of a 7A-FE, if you have deep pockets.

[rice]

Originally Posted by Flashmn

Well you could actually.
Making 200hp requires alot of work, even on the 4A-GE, and having it streetable as a 200+hp naturally aspirated engine is gonna have lot of issues. First of all you'd have to have cams that make power at very high revs, 7000-10000rpm or so. The powerband will be very narrow = not so nice on the street. Next the flywheel, crank and internals would have to be lightened, also gives some hassles in street driving. Forged high compression pistons are also needed, so you wont be able to run on anything below 98octane.

The nice part of the 4A-GE is the head, but its not so great as its made to be, honda B16 flows better stock vs stock, 4A-FE doesnt flow that much worse, plus the 4A-FE head has a better platform for head modifications, due to the runner shape and orientation, they're easier to work to better flow.

But 200hp isnt really impossible to make out of a 7A-FE, if you have deep pockets.

damn, that sounds like it would suck for daily driving and a commute car, but anyways...i've never heard of a 200+ hp N/A 4afe or 7afe, back to my question, so are you saying the great 4age responds just as good to mods as my 7afe?? hmmmm.....

[Flashmn]

Yeah it would suck for daily driving, but theres people who like to torture themselves . 240hp NA 4A-GE is a Formula atlantic engine. Hasselgren gots them.

Well they would respond to mods quite well, making power is more / less about how much money you want to spend.

[REN69]

BTW the NA 4AGE that you're talking about is probably a Formula Atlantic 4AGE which is used for racing and yes it does produce about 240-250hp... but the drawback is having to rebuild it every like 5000km That's why its a "Racing" motor.

[epyon22]

basicly you cant expect that much power out of it for a daily driver and still have it be leagle/efficent/not annoying. the reason why the 4age can produce these high horse powers is because toyota didnt underdevolpe the engine its very over devolped with steel instead of aluminum like the honda engines so it can take the stresses of high revs with the stock parts

[freakinbox]

I still think for cars the size of the corolla, 150 hp would be PLENTY!

[RadRacer3]

Next the flywheel, crank and internals would have to be lightened

This won't give the engine any more horsepower, it just means that under acceleration, less power is lost to accelerate these rotating masses. so if you have two engines with the same output, then the one with the light internals will rev up faster under the same road load.

I do agree though that both motors N/A can be made into 200+ hp engines. Although I believe the 4age has a stronger block? I know the agze has the stronger block and internals.

The important parameters are:
High Compression
Valve Timing, Overlap, Lift, and Duration
Intake & Exhaust Helmholtz tunning
Head Port mods to reduce flow separation (port, smooth, reshape... depends on application)
Fuel Delivery and Mixture
Ignition Timing and combustion effciency
Did I forget anything?

Compression ratio is known to give about 3% increase in conversion effciency for every point raise.
The valve train configuration can have very diverse effects on how the engine operates
With proper intake and exhaust tunning, large increases can be seen at specific RPM points (depends how it is tuned)

[Flashmn]

This won't give the engine any more horsepower, it just means that under acceleration, less power is lost to accelerate these rotating masses. so if you have two engines with the same output, then the one with the light internals will rev up faster under the same road load.

I know it doesnt give added horses directly, but it allows you to rev higher, in small NA engines, the only way to get power is to have a high RPM.

[toyotaspeed90]

you would probably see some sort of gain if you lightened everything up down low.... mainly because it takes power to rotate the weight.... less weight would TAKE less power to rotate... hence, you might have a slight gain

this is my idea for some day maybe in the forseeable future:
4afe block (bare, early 90's... it has the 40mm journals and still a 7 rib block)
early 4age (pre 87) crank, rods, and aftermarket pistons (balancing of the bottom end)
smallport 4age head, oversized (probably 1mm) valves, stiffer valve springs (i've heard TRD are fairly inexpensive... under $200 i believe), larger cams (bigger than the pre 87 4age... but nothing too outrageous)....

and that would probably sum up a very nice streetable 4age that would rev quickly and provide ~150hp

the formula atlantic engines aren't gonna be made anymore..... teh formula atlantic cars are getting cosworth engines from now on

[RadRacer3]

the only way to get power is to have a high RPM.

Don't forgett all the other suggestions all ready made...

You might be able to rev the engine a little higher due to the reduced mass, but not much. For the most part piston speed is consistant for most automotive engines due to gas dynamics (thermo) or the rate of heat transfer in the system.
In general smaller engines will have slightly faster piston speeds (maximum)

For example;a 1.8L @ 5200 RPM will see a piston speed of 15.3 m/s where as a 2.0L @ 5400 RPM will see a piston speed of 14.4 m/s...
wait a sec, so why is the motor with the faster piston speed running slower?? well its due to the stroke (and bore) the first motor would have a stroke of 88mm where the second motor has a smaller stroke of 80mm, thus for a slower piston speed it revs higher.

now, there are obviously other factors, engine speed is mainly due to the rate of heat generation durring combustion and stroke. (an F1 engine at 19,000RPM will have a stroke of about 50mm)

and yes, shorter stroke and smaller bore does also mean lighter rotating assemblies which in that sense will help increase max RPM.

[Flashmn]

4A-FE's are all oversquare with shorter stroke than bore, 7A-FE's are undersquare.

Anyhow, with all the money it would take you to get decent hp, I'm not implying that it would be foolish, its not, it would be creative. You'd already get a turbocharger and run over 200hp easy. 7A-FE's wouldnt be bad platforms for force induction.

[RadRacer3]

I agree...

[rice]

Originally Posted by toyotaspeed90

this is my idea for some day maybe in the forseeable future:
4afe block (bare, early 90's... it has the 40mm journals and still a 7 rib block)
early 4age (pre 87) crank, rods, and aftermarket pistons (balancing of the bottom end)
smallport 4age head, oversized (probably 1mm) valves, stiffer valve springs (i've heard TRD are fairly inexpensive... under $200 i believe), larger cams (bigger than the pre 87 4age... but nothing too outrageous)....

and that would probably sum up a very nice streetable 4age that would rev quickly and provide ~150hp

Wow, are you sure just all those internals will produce 150 hp?? with no bolt on mods?? hmmm....anywho, turbo-charging my 7afe was a top priority, considering how successful it was for some of the celica guys with their 7afe, but....after many thoughts and confusion, and putting facts together such as my 7afe is very high mileage now (close to 160,000 miles) and having to run synthetic (car might leak) and high octane fuel (i'm not the richest with a corolla), also i dont want to ruin the corolla's good gas mileage (one of the reasons why i bought it in the first place) and having a very reliable car to drive in the Winter. After i put all those facts together, i've decided to not turbo my 7afe, and i'll try to make it around the 150 hp range N/A, but after many heartaching posts, someone told me the most hp i can gain with bolts on is 15-20 hp on my 7afe??

anywho, thanks for all those who replied

[Flashmn]

Turbocharging doesnt necessarily need high octane gas, I sure as hell wont use it.

Synthetic isnt a cause for leaking oil, if it doesnt leak now, it wont leak with a turbocharger.
160,000miles, hell thats only been broken in...

Bolt ons generally dont give much power, if you want power you gotta dig inside the engine.