My 4A-GE Flywheel Bolt Too Short? Plus Extra Head Bolt Q.

[ballpencil]

This has been bugging me quite a while. Engine is 4A-GE smallport.


I think they're too short. The bolts come with the engine when i bought it.
I suspect that these are actually A/T bolts matched to a M/T flywheel.

Can anyone confirm? Should i replace them?

I'm going for a turbo conversion. Absolute don't want any flywheel bolt snapping.

Also, are ARP head studs really necessary for turbo? I'm only going for 10-14 psi max. I could really use the extra cash for something else.

[ballpencil]

i might have just answered myself..

Just found a pic of stock 4A-GE flywheel bolt on Tomei website and photoshopped it to a photo of the bolt i have.
Definitely mine is too short. Are mine A/T bolts?


Right one is my failed attempt to replace the bolts the first time. Bolt head is too big and they would just bump to each other on the flywheel.
Left one is the photoshopped stock bolt.

[YelloRolla]

ARP part number - end of trouble for you. right size, good material and end of problem.
Part No:
AR203-2802
Description:
Flywheel Bolt Kit
Toyota 4AG 10mm

[RT40Corona4AGTE]

also for low boost levels like that, a head stud kit is not really worth the effort mate. Spend your $$$ on somewhere else that could be more beneficial.

:-)

It does appear you have A/T bolts too.

[ballpencil]

cheers.. thanks for that mate. ARP flywheel bolts set is in the shopping list.

read some people saying that the head studs shouldn't be reused as they are designed to stretch upon torquing, hence one time use only. that isn't true then?
my engine has at least twice head stud torquing now: i found that it already has 0.50mm overbore pistons when i had it rebuilt the first time after i bought it.
at what boost level should i start considering head stud kits?

also just found these on the interwebs, are these true?

1. When using ARP studs, you will need to grind down one stud (the one that is near the distrubuter opening). If left the standard length, you will be unable to install the distributer. is this true?

2. The factory head bolts are fine for up to 10psi of boost. Beyond that, they stretch. Replace them with ARP head studs.

["Z" UTE]

at what boost level should i start considering head stud kits?

also just found these on the interwebs, are these true?

1. When using ARP studs, you will need to grind down one stud (the one that is near the distrubuter opening). If left the standard length, you will be unable to install the distributer. is this true?

2. The factory head bolts are fine for up to 10psi of boost. Beyond that, they stretch. Replace them with ARP head studs.

You definately have to shorten the stud nearest the CAS/ distributor, other wise that stud will prevent the CAS/dizzy engageing the gear on the cam.


cheers Chuck.

[ballpencil]

You definately have to shorten the stud nearest the CAS/ distributor, other wise that stud will prevent the CAS/dizzy engageing the gear on the cam.

cheers Chuck.

just googled about this.. it should be shortened by 4mm on the lower part so i don't lose the allen key input. curses, i'd expect a company like ARP to supply one stud shorter on their kit since this is a well-known issue. thanks for the heads-up. so that's one only bolt nearest the dizzy right? i read also i need to grind two as they prevent the camshafts from turning. so, one or two?

anyway, can i get away with just using stock ones, despite they've been torque'd AT LEAST twice? or it's just not worth the risk?

[allencr]

...can i get away with just using stock ones, despite they've been torque'd AT LEAST twice?

YES, they can be used an infinite number of times, or until the threads are damaged or are stretched beyond the factory limit. Look at the factory manual for specifics. There is never a mention of TTY/non-reusable head bolts by the factory, only by WWW twits.
The factory bolts are quality items and have been tested to about twice the factory torque without stretching by many people that've used the 'torque-angle' tightening method for steel-shim gaskets or re-torquing an already compressed OEM gasket.
Good luck.

[RT40Corona4AGTE]

some people have not needed to grind down the stud for the dizzy/CAS installation either and some have. I remember reading about this some time ago. I cant recall what the differences were that made them actually have to grind it as apposed to what the people had that didnt need the grinding.

[mookschank]

Yep, mine didn't need grinding on a 4agze bigport.