High tensile bolts for flywheel?

[JustenGT8]

What are peoples thoughts on running 8.8 high tensile bolts for a flywheel?

There's x8 M10x1.25.

I like my feet so maybe best to lash out for a set of ARP ones?

[PeteH]

OE flywheel bolts are close to 12.9 grade.......splash out on some ARP, or OE, jobbies and keep your feet......

[ed]

justen 12.9 grade is ok, but theres a couple of good toyota OEM options available too:

http://www.v-eight.com/tech_forum/vi...php?f=46&t=812

cheers
ed

[JustenGT8]

Cheers Ed, i need 30mm so 3R ones look the go...should be enough depth in the crank left for the extra 3mm?

ps glad i asked

[Sam_Q]

it's not just the grade but also the shank length. A bolt has to be matched to a flywheel

[ed]

up to a point yeah, then you pick the best option of whats available

[allencr]

it's not just the grade but also the shank length. A bolt has to be matched to a flywheel

The length is obvious, it's the diameter that's important on something that isn't also doweled.
I think you'll see the OEM stuff is ground/machined to size.

[JustenGT8]

Flywheel is M10, bolt is M10? what's the issue? OEM is M10

[RA35GT]

I think allencr is referring to the shank diameter..not the thread diameter.

The shank is the part that isn't threaded on the bolt and its diameter must match both parts to locate them correctly (where there are no dowels)
The shank also needs to be long enough to engage both parts but obviously not too long as to interfere with the thread in the hole.

[Sam_Q]

and idealy the start of the threads must not be in the same plane as the two mating surfaces as it would then focus the highest sheer force on the weakest part of the bolt. This is probably why there is a countersunk section in the crank before the threads start.

[ed]

sure, but i cat rattle of a bunch of OEM engines that ive seen where the shanked portion of the bolt ends whislt still inside the thickness of the flywheel. shanked portion locates the flywheel more precisely, but does not also engage the crank. simple torque of the bolts uses the friction between crank and flywheel to reduce shear load on the bolts.

[oldcorollas]

same as rims.. but it is more important to have a "hub locater" on the flywheel for balancing purposes

[takai]

The ARP bolts for the 4AG are even cheaper than the retail Toyota bolts. I would go with them.

[ed]

dont know about justen, but they werent long enough for mine

[takai]

Yeah, depends on the flywheel depth. Last 1UZ i used them on they were pretty much spot on.