4AGE 20V Engine Diagrams Needed!

[sillycar chick]

Hey guys, I havent sourced myself an engine manual for the 20v but I need some info on the head torque settings etc if anyone can provide it.

Just the diagrams for torque sequence, the torque settings, and any other relevant info on the head bolts (are they TTY bolts or reusable?)

51LII is bubbling a little in the radiator but im hoping (for now) to just get away with retensioning the head bolts, cos its rarely driven and if the heads gotta come off its going turbo... and I dont have money for that just yet

Thanks,
Dana

[Casey-G]

Stage1 - 29 Nm (in seq.)
stage2 - Another 90 degrees (in seq.)
&
stage3 - A further 90 degrees (in seq.)


Using this sequence




Bolts are typically non-reusable but if your only nipping them up it should be okay.



PS: Get an ARP head stud kit when you turbo it

[DX20VT]

PS: Get an ARP head stud kit when you turbo it

Why??
Becasue internet roumours say so?

They are not needed if you use new toyota ones for 1/10th the price.

[sillycar chick]

Awesome, thanks for your help guys!

[Casey-G]

Why??
Becasue internet roumours say so?

They are not needed if you use new toyota ones for 1/10th the price.

No mate, bolts stretch, studs are tensioned to a torque setting not 29Nm 90* 90* , they also distribute the pressure across the head more evenly and can hold a fuckload more pressure that the factory bolts.



Seriously man he is turbocharging it i am merely suggesting a common practice to prevent BHG's ect...

[allencr]

You won't be able to use the torque-angle method to re-tension/torque the head because the HG is already compressed, and doing that 180 degrees on an already squashed gasket will be putting the torque up to 85-95ft lbs. - about the limit of these quality Toyota stuff.
Also, the bolts are not TTY-TorqueToYield, they are infinitely reusable until the threads are damaged, its been stretched from over tightening, or the underside of the head is badly galled. I'm really tired of the TTY bullshit.
IMO there is ZERO improvement with aftermarket studs if you're only going to use factory tightening specs on them, that's why they're made of tougher steel.

[Sam_Q]

wow this is a refreshing change to see in the tech section, its good to have some hard facts instead of hearsay

[Sam_Q]

the full blacktop workshop manual is available here:

http://www.ae86drivingclub.com.au/fo...ical-Documents

[oldeskewltoy]

btw... Loynings(well known and well reputed F/A builder) only uses head studs if the engine becomes a stressed member of the chassis, otherwise they use stock OEM head bolts.

A few other notes... (just MY humble opinion) there is only one reason for Toyota having adopted a 22#s, + 90, + 90 torque value...... because the technicians of the time were too stupid, or lazy to PROPERLY torque a cylinder head. I believe the techs of the time took the 45#s and just torqued it... not doing it in multiple passes... the newer method FORCES the tech to take 3 passes

I've assembled numerous 4AG engines, and as of yet I have not had a head gasket failure while using 45#s achieved in 3 passes.

*IF* you have an older 4AGE engine manual you will see a finished torque value of 45#s. *IF* you have the TRD Bible, and have leafed through it... you will see the value is 47#s.

[Casey-G]

Im only suggesting studs because she is going to boost it... higher cylinder pressure ect... Plus if he wants to go nuts and wind 30 pound into it the motor will hold together because the factory bolts CAN stretch.

[DX20VT]

Im only suggesting studs because he is going to boost it... higher cylinder pressure ect... Plus if he wants to go nuts and wind 30 pound into it the motor will hold together because the factory bolts CAN stretch.

Well i run a turbo 20V race motor to over 500hp on standard toyota head bolts,
and have done for about 5 years of racing,
and never had a head gasket failure, apart from when it threw a fanbelt off and I kept driving it.

The standard studs are more than up to the task,
and I use a standard 20V head gasket and all done up to standard toyota torque specs.

Have heard more faults with aftermarket ones that standard ones done properly.

[Turdinator]

Im only suggesting studs because he is going to boost it... higher cylinder pressure ect... Plus if he wants to go nuts and wind 30 pound into it the motor will hold together because the factory bolts CAN stretch.

Sillycar Chick is a she...

[Casey-G]

Haha, got me there

[Casey-G]

Well i run a turbo 20V race motor to over 500hp on standard toyota head bolts,
and have done for about 5 years of racing,
and never had a head gasket failure, apart from when it threw a fanbelt off and I kept driving it.

The standard studs are more than up to the task,
and I use a standard 20V head gasket and all done up to standard toyota torque specs.

Have heard more faults with aftermarket ones that standard ones done properly.

That's awesome to hear man! really wouldn't think the factory bolts would be up to the task.


Anyhow its not worth arguing over, i studded my whole block with the intention of running high boost, but that's just me.

wasn't trying to argue, merely voicing my opinion and such on the topic.

[BLK_20v]

Arp = overpriced shiz... Factory bolts are more than sufficient...