[warning] TRD 272degree cams for 4age

[progkamol]

Hi guys, I was having nothing to do and not many people are on forum at the moment, so I decided to share this story with u guys. Well as some may knows, I am doing a GZE conversion at the moment. The reason I am putting GZE in to replace my 4-AGE 16V is because the engine is blown.

Now, lets get from the beginning, the engine was totally stock until I do some minor mods on it at around 112k on the clock eg. extractor, intake & filters, exhaust pipe and those bits & pieces outside the block. I am from Thailand, so I went back for holiday and buy all the parts I can't afford to buy in Australia (cheaper in Thailand). I've bought TRD 272degree cam shaft (2 of them), TRD valve springs, SARD fuel pump & regulator, fordge pistons, piston rings, light weight piston rods, iridium plugs, fuel injectors and CARPUTER ECU (thailand made). Could be more but thats all I remember.

As soon as I got back to Perth, all work done done buy my mates who is 3 yrs experienced in a garage in USA. All parts I purchased went in and ECU was tuned. I have also changed all brakes and clutch with all new fluids. Basicly everything was set to let this thing runs. As I thought, it went damn quick down Kwinana drag way pulling low 14s with normal tyres. I can't even believe that.

However 3 months after, I have only drove it out on the weekends all the time. One day in Bentley, I was driving up hill. Due to fuk-all light weight fly wheel, car cannot go up hill in 2nd gear (damn steep hill). So i chuck into 1st gear and drive up. As soon as I started to hit 6000rpm, where cams kicked in real hard (i mean really hard) The car just went POOP (not BANG as i thought) and smokes from bonnet and look at the rear view mirror, the whole street was covered with smokes (from my car). So I ended up being shocked and dunno what to do so I done most stupid thing in my life. I called a tow truck to tow my car from Bentley to Bentley for the distance of 1.3km and costs me $55 for that !!!

Anyway, me and my mates have a good look (personally I dunno much), my friend pulled engine apart and see what went wrong with it. Cams seem fine, and we believe it is fine. What I have suspect is I might drop a valve due to didnt tuned up properly. We tried to find what could be the cause and we've found it. And tell me, you wont even imagine that this would be the cause, you don't even think it is possible. All my valve springs breaks!!!!! How could it possible, Its TRD and its real one.This really stuffed me up real bad. So my mate went back to Bangkok and asked the TRS Vios racing team (now they use toyota vios for racing in thailand hehe). Well it turned out to be the TRD springs are real one and he said out tuning was OK. Now the question is what have went wrong? With a little research and discuss with people from TRD racing Thailand GT team. We have come to conclusion. The TRD 272degree cams give the minimal valve clearance compare to all other cams. Its even seems that it dont even cleared. Due to that it caused the cams to move faster than the springs could bounce, just a little bit faster so it still make the engine runs. They said just milli seconds faster, I dunno. That might be the caused that makes the springs breaks. But as we goes deeper, we've found out that we'll need to modify the springs to support this cams since it is too agressive! and compression ratio will need to be change. Basicly they are now still trying to verify that it was really the caused to make my springs break. They are 80% sure bout it.

So guys, with the cams you put in, you'll have to see the valve clearance and everything. Sometimes, like in my case, They would say these parts will support this cams so need to change this and that. But sometimes you'll need to modify those parts to get it runs perfect, otherwise end up like me. Now no car to use. So basicly, when u have a real agressive cams, better find out what is best for it 1st anyway. Not all race - spec stuff would allow you to rev the shit out in daily uses. like a TRD272, it was design for racing so it would be done step by step and would probably take months to get it done by pros in to those racing cars. Such a small things like valve springs, its TRD, its gonna handle this but who knows that it would need to be modify to support this monster cams.

Thanks for reading anyway

Hope this would helps

[oldcorollas]

$55 is the cheapest tow i have ever heard of

but 272 are standard lift cams?

The camshafts are TRD 272 degree, the part numbers are, 13501-AE871 for intake and 13501-AE831 for the exhaust. Lift is the same as the standard cams at 7.5mm.

(also from here)
valve clearance you SET when you put cams in, by changing the shims.

if you used real TRD springs, they would not break..

if the 272 has 7.5mm lift like standard cam, and you have TRD springs.... well.. i hate to say it, but i think you got shafted with copied goods. why else would they be that much cheaper in Thailand

what part numbers are the cams and the springs?

seems your mate has little idea.

valve clearance is pretty much set for the engine, as long as the cams are well made (ie consistent base circle)

if the springs were binding, then you would break cam before springs perhaps, but you would have chunks out of the shim/bucket and the lobe to show you.

if , as you say, the valves were floating at 6000rpm, then you have crap springs and they were not TRD... not even as good as STOCK springs...

compression is changed because the overlap of the cams lowers dynamic compression..

sounds liek you got shafted

[RONA]

$55 is the cheapest tow i have ever heard of

It was for only 1.3km

[oldcorollas]

would you spend half an hour picking up a car, towing it 1.3km and unloading it for less than $50? thats probably just call out fee

[takai]

$50 is what i get pretty much all my towing done for.
Makes it cheaper than hiring a trailer most of the time

But yeah, does sound like substandard quality parts, especially if they did go bang all at once.

[Ben Wilson]

The springs weren't coil binding were they?

[progkamol]

Well the springs are brand new when I bought it. I went to the shop behind the race circuit to buy one. Its came with a lable sticker on packaging with TRD logo and part number on it. I dunno about the packaging that they does normally come with box or whatever. But the springs are inside a clear packaging plastic sleeve, sealed with the lable on. Could it be fake or coppied one? If it was the springs problems I wuld blame myself then .. but if it was the tuning .. who should I blame?

[oldcorollas]

springs failing is a mechanical problem, not a tuning problem...

how much lift do the cams have? if they are TRD 272 with 7.5mm lift, then even stock springs will nto bind.. so i guess first thing to do is check what lift the cams have (simple measuring of the lobe with vernier calipers)

[Garth AE86]

The camshafts are TRD 272 degree, the part numbers are, 13501-AE871 for intake and 13501-AE831 for the exhaust. Lift is the same as the standard cams at 7.5mm.

theres your problem. the TRD levin&trueno bible has some bad news.

13501-AE871 CAMSHAFT, intake, 272°, 7.5mm
is correct, no problems there but...

the part number 13501-AE831 does not exist

are you POSITIVE it is this part number? did you misread the label? it is impossible to run an intake cam on the exhaust due to the missing distributor drive gear.

the part number for the item you most likely have is:
13502-AE831 CAMSHAFT, exhaust, 272°, 10.0mm

which needs a .34 clearance to accomodate the 10.0mm lift.
This is why if you installed this cam profile with a 7.5mm spec clearance of .25 you would fuck your springs up good and proper as you have most likely done.

The correct exhaust camshaft part number you want is:
13502-AE871 CAMSHAFT, exhaust, 272°, 7.5mm
i am 100% positive of that.

the 2 in 13502 means 'exhaust'.

[1200det]

http://www.mr2supercharger.com/4AGECamspecs.html

AE831 is listed there !!!!!


.

theres your problem. the TRD levin&trueno bible has some bad news.

13501-AE871 CAMSHAFT, intake, 272°, 7.5mm
is correct, no problems there but...

the part number 13501-AE831 does not exist

are you POSITIVE it is this part number? did you misread the label? it is impossible to run an intake cam on the exhaust due to the missing distributor drive gear.

the part number for the item you most likely have is:
13502-AE831 CAMSHAFT, exhaust, 272°, 10.0mm

which needs a .34 clearance to accomodate the 10.0mm lift.
This is why if you installed this cam profile with a 7.5mm spec clearance of .25 you would fuck your springs up good and proper as you have most likely done.

The correct exhaust camshaft part number you want is:
13502-AE871 CAMSHAFT, exhaust, 272°, 7.5mm
i am 100% positive of that.

the 2 in 13502 means 'exhaust'.

[Garth AE86]

also, i found this link for you if you dont have access to the TRD book 'corolla levin, sprinter trueno special edition bible'

http://www.geocities.com/motorcity/7...camshafts.html

[Garth AE86]

http://www.mr2supercharger.com/4AGECamspecs.html

AE831 is listed there !!!!!


.

it sure is, and look at that prefix... 13502

[AE101LEV]

ooooooooo that dont sound goood jsut hope u havent got two inlet cams & u pressed 1 insted of 2 on the keyboard

[takai]

Well he cant run two inlet cams, the exhaust has a driven gear for the dizzy.
I can well see that if he was running 10mm lift the valves would be binding quite nicely and would go pop quite quickly.

[Garth AE86]

which is the exact reason i stated as to why i think he has misread the part number and consequently fucked his car