3T GTE Tech

[YelloRolla]

No pattern really for ring land failures, maybe just a spate of them on #4 recently. My engine failed on #3, I've seen some engines with 3 out of 4 pistons suffering from broken ring lands, Johnnies engine did #3 on a couple of occasions.

[steeko]

cool.. I got a new upper guide from that guy in the states, cant remember his url. Is the lower guide for 3tc u speak of from toyota parts aus?

[steeko]

dudes, looking on the kameari website, they have a gear drive kit for 815 bux, but is for the 2tg, can it be used to replace my 3tgte timing chain completely? It is 3 gears which interlink and does away with tensioners, guides and sprockets etc

[turbotoy]

Something I have been working on!

[3sgte]

Weather permitting, I am going to start pulling the engine out/apart tomorrow.

If anyone has or can point me to a repair manual (Japanese or English) I would be greatly indebted. I found nothing via Google.
The only engines with chains I've ever done are a 22R and 1NZ-FE, so I'd like to get myself an overview before I start.

On a different note, what is the 3TGTE bellhousing the same as?
I have a good Gen4 3SGTE sitting collecting dust, and I am sorely tempted to try chucking it in instead.

Edit,
I shouldn't pollute this thread with the 3sgte question.
I'll start a different thread for that.

[Spectre]

Depends what box you want to put behind it. You want the standard T-W box, to put a W55/57/58 behind.

[3sgte]

Well, I pulled the head off it today.
I couldn't get a cherry picker, so I just pulled the head in the car.

It might just be my lack of familiarity, but it seemed quite a bit more difficult to work on than a 3SGTE in a 4WD Celica.

Oh, and damn, but was that head ever stuck to the block!
I rechecked about 4 times, plus asked a buddy to look, as I didn't think I got all the bolts out.

A shame too, as the headgasket was in perfect shape.

Head:


Piston:


Cylinder wall:


I won't have a chance to work on it again until next weekend.
I'll be pulling the bottom end, checking the crank and measuring the bores.

It is a foregone conclusion now that I need a rebore, as what is there won't clean up with just a quick hone.
Fortunately it seems like there is meat enough to work with, measuring hopefully will confirm that.

[AE25]

nice intake manifold turbotoy
all these #3 & 4 pistons going bang.. would this suggest a weak fuel delivery system? 1st injectors getting more pressure than the rears so if a lean out occurs.. the rear ones die first?
If taking head off. check head and block are flat. no kidding they do get warpage.
Bores can be bored out to 89mm but wouldn't recommend that with boost added.

So after all my theory, the problem is the bore on the pressure relief valve wears due to the alloy body and steel piston after many years and results in a stuck relief piston. Putting in a new body fixes the problem.

I concur. had problems with oil pressure but yet to find the relief valve stuck. although a friend who races a te71 3tgte has. when the pump pulled out, he took off the relief valve nut and valve piston stayed in the bore, gave it a little nudge and it popped out and slid in and out freely.
Weird how this happens when cold.. surely piston/bore clearance is smaller when cold. alloy expands more. could it be it jams when engine hot and the hotter (less viscous) oil can bypass the stuck valve.
High flow oil pump (3tgte std) can be bought from BRD racing in the states.
http://brdracing.com/toyota_2tc_3tc_oil.htm
looks to be a 2t/3t pickup + spacer plate with the deeper 3tgte (18rg?) rotor.
a comparison here
http://toycrazy.net/tech/comparisonpics/t-oilpumps.jpg

[steeko]

dudes, here's the gear drive kit i'm looking at to replace my timing chain.
Question is, will it work for a 3TGTE as the Kameari website states it is for a 2TG

http://www.kameariusa.com/2TG_GearTrain.php

[turbotoy]

2tg drive will be fine!

[steeko]

thanks for the info TurboToy, have you seen it installed on a 3TGTE anywhere?

Pretty keen on it if it eliminates alot of drama's associated with timing chain setup (sprockets, tensioner, guides, chain). Also can anyone see any disadvantages of the drive kit vs timing belt ??

[3jcelica]

Only disadvantages I see are noise (timing gears will make a nice winning noise although sounds great on a track car might become painful over time) and Cost.

You still have the upper timing chain with this setup, which tends to be the more troublemsome.

I have never had problems with lower timing chain gear so I don't see reliability as much of an argument.

Roger

[Joshstix]

Yeah it seems like fixing something that shouldn't actually be a problem. Chain drive cams are a very well proven tech, admittedly having multiple chains is pretty ghey but it should still be reliable. Not to put too fine a point on it but I think your problem is caused by the human error that can occur during an engine build rather than a real weakness of the design.

[steeko]

thanks for the feedback, does anyone have a frontal pic of the 3TGTE with all of the timing components exposed so I can get a better idea of how it works?

[3jcelica]

Here is a pick of the 3tc timing chain setup, equivalant to the gear set in oprevious pics. On a 3tc the larger cog drives the cam, on a 3tgte the larger cog drives a dummy shaft and this shaft has another cog on it to drive two cams

http://www.dragtimes.com/images-clas...0510870003.jpg