4AGE 20V Top Overhaul / Full Overhaul

[pcmoddingmy]

Hi guys,
I think this question has been asked quite a lot of times already and still seems a little bit unclear about top overhaul or full overhaul for 4AGE 20V.

Basically, I was told that top overhaul is top overhaul which means removing the head only (engine still attached to the car) and working on the head only. Most workshop also provide top overhaul + piston ring changes without actually dropping out the engine, not forgetting grind valve. Apparently, they'll just pop out the oil pan and remove pistons, conrods, bearing and etc from the block to change piston ring while the block is still in the engine bay.

As for full overhaul, they basically drop out the engine and replace every single thing in the engine which are worn out and "best replaced". Only necessary if piston is damaged and requires reboring onto the block, or engine is seriously terrible condition. A compression check will roughly tell if you need a full overhaul or just a top overhaul.

So seeing that my engine is consuming quite a bit of engine oil and also spitting out white smoke (noticeable via my rear view mirror) so I guess its time for overhaul. So, hoping that my pistons are "ok" and also no problem with the block, the best way for me is top overhaul with piston ring changed. FYI, I've already tried changing to "engine kosong" before which costs about RM1.3k for the engine alone.

So I called up and meet up a few guys/foremans and they quoted me about RM1100+1300 for the job including workmanship and parts as well (with TRD 0.8mm metal gasket). Some workshop also included new conrod, bearings and polished intake/exhaust ports for the same cost. Some only provide workmanship whereas the parts must be provided by customers.

Basically this is the rough rundown for 20V BT (all using original OEM parts unless specified):
Workmanship + Grindvalve: RM350-500
Top set: RM200-230
TRD 0.8mm Metal head gasket: RM250-280
Conrod, main bearing, engine bearing: RM150-200
Polishing inlet/exhaust ports: RM200
Time required: 2-4 days

So the reason for this topic is to hear from you guys about this and also doing an overhaul guide for our beloved 20V engines. If you guys have experienced with better pricing and service, please do not hesitate to post it here. Workshop owners/runners can also post your pricing here for reference.

Update: Toyota 4AGE 20V (or any other Toyota) Parts Reference (http://www.toyodiy.com/parts/)

 

[scomatic]

I think if NA, better go for 0.4mm metal head gasket

 

[2 Old 2 Rusty]

Normally, you just do a top overhaul for oil consuming cases, bro.

Change the top set stuff (the valve seals etc which is all included in the top set gasket set), piston rings & the con rod bearings; that's all.

The con rods are seldom required to be changed, unless it is bent or worn. If the cranshaft bearing needs to be changed too, it's considered as a completed overhaul; which then the pistons will be inspected to determine if it needs to be replaced i.e. the cylinder walls are scratched & so forth.

If you're contemplating a full overhaul, you may also want to consider lightening & balancing & oversize pistons; other just port & polishing the head....poison...

A 0.6 mm metal gasket should also raise the compression, besides using SVT pistons.

You should also consider porting the throttle bodies to slightly larger dia, slightly bigger injectors, lightweight flywheel, higher lift cams etc.

So a budget of around RM 10k should be able to see you thru on this project.

 

[scottwrx]

Normally, you just do a top overhaul for oil consuming cases, bro.

Change the top set stuff (the valve seals etc which is all included in the top set gasket set), piston rings & the con rod bearings; that's all.

The con rods are seldom required to be changed, unless it is bent or worn. If the cranshaft bearing needs to be changed too, it's considered as a completed overhaul; which then the pistons will be inspected to determine if it needs to be replaced i.e. the cylinder walls are scratched & so forth.

If you're contemplating a full overhaul, you may also want to consider lightening & balancing & oversize pistons; other just port & polishing the head....poison...

A 0.6 mm metal gasket should also raise the compression, besides using SVT pistons.

You should also consider porting the throttle bodies to slightly larger dia, slightly bigger injectors, lightweight flywheel, higher lift cams etc.

So a budget of around RM 10k should be able to see you thru on this project.

wah.. this racun kuat kuat one..... sifu 2o2r,

got a noob question to ask u lah.. coz my 7A fe wanna kahwin with my 4a GE liao.. what is the reccomended gasket ar? i will be using bt piston with bt head.... according to bro howard, he is using 0.5mm get around 12 for compression, but it is too high to be driven smoothly, i prefer to go back to standard bt compression of around 11 to 11.5
is 0.7 ok? or 1mm? i know there is a way to claculate but i couldnt find it so have to ask u sifu loh...

another noob question, northern got ppl do engine balancing? it got around how much?

 

[scomatic]

You should also consider porting the throttle bodies to slightly larger dia, slightly bigger injectors, lightweight flywheel, higher lift cams etc.

bro... bigger the throttle body size didn't make any improvement on our 4AGE. The result are the same as I have a dyno report on a engine that has had that mods done and there was a 1hp - 2hp improvement. This is more likely to be dyno error that any actual increase in power as such. The factory TB is 55mm in diameter, and while it may not seem to be that large remember that the engine only has one cylinder sucking at a time, so a 55mm hole is actually quite large. FWIW, a typical twin Weber 45mm set-up for a big HP 4AGE would have something like 40mm chokes for each cylinder, which is obviously a lot smaller (~53% the area) than the 55mm TB.

Last you also forgot 1 thing about the cam too. It is higher degree of cam, depend on lift only was not enough le... poison...

Bump:

wah.. this racun kuat kuat one..... sifu 2o2r,

got a noob question to ask u lah.. coz my 7A fe wanna kahwin with my 4a GE liao.. what is the reccomended gasket ar? i will be using bt piston with bt head.... according to bro howard, he is using 0.5mm get around 12 for compression, but it is too high to be driven smoothly, i prefer to go back to standard bt compression of around 11 to 11.5
is 0.7 ok? or 1mm? i know there is a way to claculate but i couldnt find it so have to ask u sifu loh...

another noob question, northern got ppl do engine balancing? it got around how much?

haha... later we all mati because of racun le.. ** just kidding ** ...

Actually i do used the 0.4mm gasket before, didn't got any un-smooth problems. NA if more thickness, the more compression you can get it from, and the more power can get from too.

OEM metal or standard gasket was 0.8mm only. 1.0mm gasket much for supercharge use. Turbo should use 1.5 mm to 2.0mm metal gasket.

 

[2 Old 2 Rusty]

bro... bigger the throttle body size didn't make any improvement on our 4AGE. The result are the same as I have a dyno report on a engine that has had that mods done and there was a 1hp - 2hp improvement. This is more likely to be dyno error that any actual increase in power as such. The factory TB is 55mm in diameter, and while it may not seem to be that large remember that the engine only has one cylinder sucking at a time, so a 55mm hole is actually quite large. FWIW, a typical twin Weber 45mm set-up for a big HP 4AGE would have something like 40mm chokes for each cylinder, which is obviously a lot smaller (~53% the area) than the 55mm TB.

Last you also forgot 1 thing about the cam too. It is higher degree of cam, depend on lift only was not enough le... poison...

Bump:

haha... later we all mati because of racun le.. ** just kidding ** ...

Actually i do used the 0.4mm gasket before, didn't got any un-smooth problems. NA if more thickness, the more compression you can get it from, and the more power can get from too.

OEM metal or standard gasket was 0.8mm only. 1.0mm gasket much for supercharge use. Turbo should use 1.5 mm to 2.0mm metal gasket.

Oic,

My apologies, sifu Scomatic. I don't know nuts, please forgive me for the wrong information.

Guys, pls forget what I just said. It's all nonsense. Pls listen to sifu Scomatic.

 

[scomatic]

Oic,

My apologies, sifu Scomatic. I don't know nuts, please forgive me for the wrong information.

Guys, pls forget what I just said. It's all nonsense. Pls listen to sifu Scomatic.

what la you... I just kidding only la... don't be serious pls... All the thing is also useful. I'm noob too, don't listen to me!

2O2R don't over size my nick le.... over size pulley might get me hit the break le...

 

[scottwrx]

A 0.6 mm metal gasket should also raise the compression, besides using SVT pistons.

You should also consider porting the throttle bodies to slightly larger dia, slightly bigger injectors, lightweight flywheel, higher lift cams etc.

So a budget of around RM 10k should be able to see you thru on this project.

hehehe... noob know what is missing liao.... higher lift need better management team, soo u need to hire mr dastek, mr haltech, ms motec etc.... they stand alone so can manage ur car better.. muahahaha.. budget 13k exclusive tuning... muahahaha.....

 

[scomatic]

hehehe... noob know what is missing liao.... higher lift need better management team, soo u need to hire mr dastek, mr haltech, ms motec etc.... they stand alone so can manage ur car better.. muahahaha.. budget 13k exclusive tuning... muahahaha.....

wa.... that also you realize...
haha... waiting to see the ms motec le... sure very pretty 1....

 

[pcmoddingmy]

Guys, thanks for the input but seriously lets talk about keeping things "stock" first okay? :rolleyes:
Playing performance stuff is way too expensive for NA and the HP gain is not much compared to FI, at least for me. Anyways, bro 2O2R are you saying that SVT pistons have higher compression than BT pistons? But didn't Toyota spec rated the BT to have higher comp than SVT?

I think 0.4mm head gasket will raise up the comp quite high and one of my fren using it on his 16V and facing serious knocking and he had to tone down the timing. IIRC, 20V BT's stock head gasket thickness is about 1.0mm or something. Besides, TRD parts list shows only 0.8mm available for 20V (http://www.trdparts.jp/english/parts_engine-4a-g20.html)

If I had 10K, I'd rather just plonk in a 4AGTE 16V and have more power to even smoke an RB20DET. Seriously, a 4AGTE on corolla is madness and you'll be fighting with the steering for most of the time. Anyways, that's another story... :hmmmm:

 

[scottwrx]

wa.... that also you realize...
haha... waiting to see the ms motec le... sure very pretty 1....

pretty ar.. subjective loh... coz she is australlian chick mah... supersize one woh.. D cup u can tahan or not?????

hehehe......

btw way.. lets get back to the topic lah....

Bump: during conversion, i asked a lot about overhaul n things like that this is what i know lah..

oil consumption is due to 2 things, worn piston rings or worn valve seal, i think u need to check the piston clearance coz quite seldom the will be worn on the block, is not juz change the ttop set lah... including valve seal, oil seal, gasket...etc... basically anything the is inside the head lah...

bt in nature has higher compression, bt 11.1 : 1 and svt 10.6 : 1, using a thinner gasket (lessor than 1mm) will increase higher compression in return a slightly higher power... i think bro 2o2r mean is that using svt piston, conrod n crank with stand a higher rev, coz stronger, therefore more potential for future mod...

grindvalve , porting polish - according to some other guys, there will be no remarkable difference in the performance, so can save the mpney for something else...

bearing - i have read the bill sherwood page and he mentioned not to spend money on racing bearing or kings bearing the investment is not worth of the result, might as well stick with oem toyota one...

engine balancing i m still searching for the correct solution n answer for engine balancing as from what i know, proper balancing will produce a better respond particularly in the high rev, due to the same momentum n the crank shaft will have less burden compensation the difference momentum of each piston&a

anyway that is what i know n experience lah.... still need help of the 7A conversion.....

dun shoot if wrong..

 

[scomatic]

Guys, thanks for the input but seriously lets talk about keeping things "stock" first okay? :rolleyes:
Playing performance stuff is way too expensive for NA and the HP gain is not much compared to FI, at least for me. Anyways, bro 2O2R are you saying that SVT pistons have higher compression than BT pistons? But didn't Toyota spec rated the BT to have higher comp than SVT?

I think 0.4mm head gasket will raise up the comp quite high and one of my fren using it on his 16V and facing serious knocking and he had to tone down the timing. IIRC, 20V BT's stock head gasket thickness is about 1.0mm or something. Besides, TRD parts list shows only 0.8mm available for 20V (http://www.trdparts.jp/english/parts_engine-4a-g20.html)

If I had 10K, I'd rather just plonk in a 4AGTE 16V and have more power to even smoke an RB20DET. Seriously, a 4AGTE on corolla is madness and you'll be fighting with the steering for most of the time. Anyways, that's another story... :hmmmm:

BT compression definitely will be higher than svt...

OEM gasket should be 0.8mm la... 0.4mm will knocking? I think the timing was wrong. Anyway, i worry is they use the TVIS injector... Because TVIS injector was product at 182 cc (if not mistaken). Try use the 235 cc injector from Non TVIS.

Why say BT can use 0.4mm, is because BT was used about 295 cc injector already. It should enough to stand that high compression. If still not enough, try to add the Fuel Regulator.

Wa,,, if have 10k, i rather not to play 4AGE already.... I will aim for ST215 - 3SGTE engine or even SR20DET already le.... because 1 day u will feel it too expensive to gain power.

Bump:

pretty ar.. subjective loh... coz she is australlian chick mah... supersize one woh.. D cup u can tahan or not?????


grindvalve , porting polish - according to some other guys, there will be no remarkable difference in the performance, so can save the mpney for something else...

bearing - i have read the bill sherwood page and he mentioned not to spend money on racing bearing or kings bearing the investment is not worth of the result, might as well stick with oem toyota one...

engine balancing i m still searching for the correct solution n answer for engine balancing as from what i know, proper balancing will produce a better respond particularly in the high rev, due to the same momentum n the crank shaft will have less burden compensation the difference momentum of each piston&a

Out topic:
Ms Motec got D cup only ka? Aiyooo.... rugi la... I think she had DD cup.... wahahahaha....

In topic:
grindvalve , porting polish <-- yes can help to increase a bit... if money is available, try to use the oversize valve, and aftermarket valve spring too... It also can help.

bearing <-- better to change, if found it worm out already. Sherwood was mention is about NA, yes the NA doesn't need high quality bearing. But turbo is another story too.

engine balancing <-- If using blacktop crank, i think factory already balance at 12000 rpm already. engine balancing is not the cheap thing to do. So please stand by money le...

conclusion is all about money. No money no mod... More money more mod... less money less mod....
same as me... bankrupt already ma... so stop mod car for quite some month already.

 

[chinozie]

scomatic - 2O2R already mentioned...slightly...not too big...

You should also consider porting the throttle bodies to slightly larger dia, slightly bigger injectors, lightweight flywheel, higher lift cams etc.

it will crease the air flow to allow smooth fuel mixture...


plus...you wrote :

NA if more thickness, the more compression you can get it from, and the more power can get from too.

it's not actually...
it's all about compression ratio...what important the most...if it's too high...reduce it...to low increase it...

it's all depends on what range of power do you what to play, what type of race/drag/track you want to use...

all those input need to change accordingly base on what kind of race or power that you required...

it's like...you put a drag car in a track circuit...heeee...or vice versa...

diff power...diff application diff use...

not all the same...

:D

correct me if i'm wrong...

 

[banzai]

If I had 10K, I'd rather just plonk in a 4AGTE 16V and have more power to even smoke an RB20DET. Seriously, a 4AGTE on corolla is madness and you'll be fighting with the steering for most of the time. Anyways, that's another story... :hmmmm:

that is very true. 4AGTE is serious sh*t.

 

[BDK8671]

i heard some mechanic say BT/SVT-20V cant be grindvalve .....cuz the engine is running with "shim" .....

and after doing overhual ....the individual shim need to replace to original location/point ....if not ...the timing will be run out .....

izzit true ?? ....pls comment ....:stupid::stupid: