WTA 7AGE pro n cons

[GT'd]

huhu got serious project here, good luck bro scott
want to meet u when go back to sp

 

[jaist150]

bro, 7age normally use to which model of toyota car?

 

[normality78]

btw, the 7A block n flywheel already parking at my house now.. muahahahaha.......

all sifus, plz share wif me the following doubts that i have,

1. timing belt, is there any alternative other than porsche 944?
2. how to modify the oil squirters to the 7A block
3. 7a conrod to 4a piston jus pnp, or need some work?
4. need to skim the block for higher compression?
5. i saw from club 4ag, saying that crank balancing will produce prevent power loss after 7000rpm, anyone got experience in this? what do i need to bring for balancing, crank n flywheel only? or piston crank flywheel block....etc..? must use 4a piston or 7a piston for balancing? coz i only got one car.. cannot afford to spend 1 month in the work shop.. how much is the balancing cost?

1. Recently i met a guy in a workshop, whom just done installing turbo kit on his 7AGE. Had a little chat with him and he said he was using power belt. I asked him where he get he said order from japan. I can help you ask again if i bump into him coz i dont have his contact.

4. If you're going to NA route, mostly plp change to higher comp piston or use thinner gasket. AFAIK, 7A on default was already metal gasket and rated 0.7/0.8mm if i was not wrong. I dont favour skim head unless you head/block surface wasnt even anymore

 

[scottwrx]

bro, 7age normally use to which model of toyota car?

there is no such thing as 7age, 7age comes from 4age + 7afe hybrid, meaning 4age head match with 7a block, reason being higher power output, coz 7a block is 1.8

in other words is 1.8l twin cam 4 throttle vvt... power.... muahaha...

 

[1JZtezza]

1.8l 4age is not new.Some time ago there was available TRD crank for 1.8l,this was used in early 1990 toyota levine rally car.What u want is only the 7af/ag crank only;safer to go for 4ag con rods especially the 4th gen 16v model.You may need to grind/chamfer con rods and block for clearance.
Apparently difference in stroke is entirely due to crank.(sorry cant remember) If so use the 4age block which is stronger (check out bill sherwood's 4age page)Before putting everything together check valve clearance first;else all the effort would be wasted by just cranking the car.
Check all the tolerances first then order TRD bearings,pistons,valve springs,(got balls try 304/304 cams)Forget trd valves because my experience is machine/engineering shops dont work to very fine tolerances and u find the valves sitting at different heights on the cylinder head.Need to change the shim buckets to trd where the shim sits underneath.This is the most time consuming part of this build, getting the shimming right.
ECU -cant help here;ran a trd distributor with twin weber 45 DCOE.
GOOD FOR 11,000 rpm-it has been done!!!
You are a BRAVE man to try this for a 20v head-no experience here but would like to know your result-good luck!

 

[NA_Lover]

ECU -cant help here;ran a trd distributor with twin weber 45 DCOE.

Wow?!? Blacktop running with carburetors?!? Sounds awesome man.. muscle car style. I like.
Didn't know it was possible. Must research.

GOOD FOR 11,000 rpm-it has been done!!!

It is currently my dream to get my engine to rev and maintain the power all the way to this fabled limit. But its kinda like the HOLY GRAIL.. mysterious, hard to research, very little background material to work on.

But I did do sum estimates though. If we were able to obtain a smaller bore sized block along with fitting piston heads, we could probably rebalance the 4A crank to compensate for the shorter stroke. So while still maintaining an overall cylinder volume of close to 1600cc (optimum scenario), we'll have a smaller, rev happy engine that might be able to withstand revs of 11k.

Of course, my calculations were made based on the principal that smaller cylinder bores always yields higher RPMs. But it did occur to me at some point, that we would have lost the entire low end torque if this were to be done.

So if there is a way to obtain 11k rpm and still maintain increasingly usable power and torque throughout the rev range with a 7A; it'll be an NA_Lover's wet dream come through!

Aw nuts, I think I just crapped my pants thinking about it. Damn.

 

[1JZtezza]

twin webers were for the 'old' 16valve but would theoretically be posibble for the 20valve since they got the 4 throttle manifold but you would need an ECU to match fuel with the vvti function.

I think it was the HKS crank with special short skirt pistons while still retaining 4age block --NOT 7AG/AF sorry for the mislead here.

Timing belt-was using 'old' 16valve belt.If using 7ag block make sure u count the teeth on belt and pulley (cam turns half the speed of crank)

dont think you could use 304/304 cams WITH vvti--nightmare for cam setting.But if u want 11000 rpm u gotta use 304/304 ( high lift and not standard lift-11mm I think).Pulls from 5000rpm all the way to 10000rpm in a blink.

PISTON HEAD AND VALVE CLEARANCE IS CRITICAL-else you will just destroy a lot of effort and money before having the chance to enjoy it

If you are stuck in traffic jam with such configuration then better be expert in heel/toe to keep the engine alive!!!

Again good luck and keep posting here.I am keen to know the outcome

Bump: Also a nicely balanced engine can do high revs-
corolla 4K engine with pushrods have done 9000 rpm

Bump: Also a nicely balanced engine can do high revs-
corolla 4K engine with pushrods have done 9000 rpm

 

[normality78]

1.8l 4age is not new.Some time ago there was available TRD crank for 1.8l,this was used in early 1990 toyota levine rally car.What u want is only the 7af/ag crank only;safer to go for 4ag con rods especially the 4th gen 16v model.You may need to grind/chamfer con rods and block for clearance.
Apparently difference in stroke is entirely due to crank.(sorry cant remember)

bro, if im not wrong, the 7a deck is also higher. Same as rod

 

[NA_Lover]

True. 7A block is higher.
Thats why if mod need to retain the 7A conrods and crank. (as far as I know la)

But of course if got the dough, definitely go for a custom aftermarket fitting la.. 7A so old jor..

I think valve clearance can check by hand.. after masuk the stuff's, hang the engine on a rack and just pusing pusing crankshaft a bit to check for resistance. As long as each piston at TDC don't exceed a certain point should be safe. But unless you doing DIY I think the foreman would do these stuffs for you la..

But I figure its really tough to reach 11k rpm lor.. valve spring all have to change. All pulleys have to change to heavy duty lightened performance. Crankshaft and conrods need perfect pinpoint balance. Engine block need to be thick and strong. Gearbox need light but durable flywheel and multi-plate clutch to handle the engine speed otherwise would break oso..

But all that being said... NOT giving up so easily.
Where there's a will there's a way!
Just need the bank account to compensate!

Btw, stock 7A block can stand 11k rpms? Can a timing belt even take 11k rpm in the first place? Wouldn't it just snap?

 

[normality78]

i tihnk the block itself should not be any problem but more on can those components take it?

 

[1JZtezza]

longer stroke does not necessary mean longer con rods.
4age-16valve bore 81mm x stroke 77mm
7age- bore 81mm x stroke 85.5mm
So 85.5mm minus 77mm divided by 2 gives u the extra radius needed by crank to give you the required 1.8l ie the rotation radius from centre of crank in 4age is 38.5m whereas for the HKS crank is 42.75mm an increase of 4.25mm.If this is the same with 7ag/af then life would really be a whole lot simpler.Like i said earlier it was a HKS crank but you will have to measure the 7age crank yourself to confirm.Would save you guys a whole lotta grief.So take out your calipers and start measuring!THEN you can use back all the 4age stuff---pulleys,cams belts etc

Bump: uhm silly question here --why cant just bolt 4age 16valve head to 7af block.Difference is the valve angles only.Use back 7af timing belt.Silly me thought 7af single cam but its twin cam right?
If that can be done then bolt blacktop head on should be also ok.But run the 4age or blacktop ecu because the 7af was meant more for economy.

Anyone tried 3sg or 3sgte in rear wheel drive corolla?????

Bump: uhm silly question here --why cant just bolt 4age 16valve head to 7af block.Difference is the valve angles only.Use back 7af timing belt.Silly me thought 7af single cam but its twin cam right?
If that can be done then bolt blacktop head on should be also ok.But run the 4age or blacktop ecu because the 7af was meant more for economy.

Anyone tried 3sg or 3sgte in rear wheel drive corolla?????

 

[NA_Lover]

longer stroke does not necessary mean longer con rods.
4age-16valve bore 81mm x stroke 77mm
7age- bore 81mm x stroke 85.5mm
So 85.5mm minus 77mm divided by 2 gives u the extra radius needed by crank to give you the required 1.8l ie the rotation radius from centre of crank in 4age is 38.5m whereas for the HKS crank is 42.75mm an increase of 4.25mm.If this is the same with 7ag/af then life would really be a whole lot simpler.Like i said earlier it was a HKS crank but you will have to measure the 7age crank yourself to confirm.Would save you guys a whole lotta grief.So take out your calipers and start measuring!THEN you can use back all the 4age stuff---pulleys,cams belts etc

Ya, that far I can understand I think.
Measure the difference in stroke and apply the difference in value to the crankshaft to compensate.

But I figure the crankshaft and conrods might already come with the 7A block during purchase. So shouldn't be a problem if we're to reuse them in the build. The only change is that need to get a timing belt of proper fit.. which I think in previous builds some guys did used the Porsche belt to good effect.

Just some random interesting facts though (according to the measurements given above)...

4A-GE Swept Volume of ONE cylinder:
8.1cm x 8.1cm x pi/4 x 7.7cm(Stroke)= 396.78cc

4A-GE Overall engine volume:
396.78 x 4 (cylinders) = 1587.12cc

---------------------------------------------------------------------------------------------

7A-GE rebuilt Swept Volume of ONE cylinder:
8.1cm x 8.1cm x pi/4 x 8.55cm (Stroke) = 440.58cc

7A-GE Overall engine volume:
440.58 x 4(cylinders) = 1762.33cc

---------------------------------------------------------------------------------------------


Sorry guys, I couldn't resist.
Don't you just love calculating engine figures?

 

[wfhan]

i totally don't understands the formula, but i like the total cc.. ehhee

 

[NA_Lover]

i totally don't understands the formula, but i like the total cc.. ehhee

No worries bro. Its a lot less complicated than it looks.

Now if we were to measure the volume of a completely flat SQUARE surface.. we would use the following formula:

Height x Width= Volume of Flat 2D surface

But if we were to measure volume of a cylinder in that sense, which occupies 3D space, we would replace Height with Bore Diameter squared and Width with Stroke length. And we also know that according to Archimedes, in order to get the overall volume of anything round, we have to times that with Pi/4
(Where Pi is 22/7)
So the formula would write as follows:

Bore Diameter x Bore Diameter x Stroke Length x Pi/4 = Volume of ONE Cylinder (In CC)

Now at this point, we would have found the volume of ONE cylinder on the engine. So in order to find the overall volume, we just have to times that value with how many cylinders we have. So in the case of the 4A or 7A we have 4 cylinders:

Volume of ONE Cylinder x 4 = Overall 4A/7A Engine Volume

The formula comes in handy when you want to know EXACTLY how much extra volume your engine has after modding. No sweat man! Take it easy!

Hope that helps a little.

 

[scottwrx]

bro... make it simpler lah... dun use pie n stuff like that mah.. juz say in order to calculate the displacement.. we need bore n stroke length...

bore area x stroke length = volume = cc

some to calculare bore area = bore/2 x bore/2 x 3.142 ( pie)

then times stroke then got volume per cylinder loh...

example 8.1/2 x8.1/2 x3.142 = 51.53 x 7.7 (stroke) = 396.8 cc per cylinder

then 4 cylinder = 396.8 x 4 = 1587cc loh..

 

[1JZtezza]

Before getting started check out this site:

http://www.billzilla.org/starleteng.htm

Do check out this site as he has made some HUGE hp figures(no sure if its on the wheel)

For the AF engines they run only ONE cam pulley-the other cam is turned via a gear so the cams rotate in opposite direction(sorry now only can remember)
The 20valve has timing belt turning BOTH cams and they rotate in same direction.Looks like the better bet on timing belt would be the 20valver.

Ideally is get both engines; strip it down and then rebuild with 'tlc'(tender loving care)
You can not rush this.Not ideal if your daily ride is down for 2-3 weeks
Warning:con rod bolts are prone to failure--ALWAYS USE NEW ONES IN REBUILDS--I kena before
reason is bolts when torque they stretch so when you re-use them they stretch some more-when it breaks you dont know!!

Which is more cost effective-you got to work it out yourself-HKS crank and short skirt pistons or the above.