... I refitted my pick of a bunch of used bolts, some of the heads had rounded on the originals when I took it apart

edit: watching initial D isn't helping right now with Takumi's new 11,000rpm engine, I want 11,000 rpm to atomise that fuel!

Quote:
A couple of tricks I've used on high tensile bolts.
#1 Oxy/Acet torch with 000 or smaller tip, run it slightly-lean and de-temper the center of the bolt.
Work quickly, only turning the bolt red, spray with penetrant AFTER the fire hazard has cooled.

#2 Plunge-Cut with a 1/4" Air Die Grinder, use a Ball Burr, double cut makes safer shavings, singe cut burrs make HAZARDS!

This works well removing Titanium Pop-Rivets also.
{Electric Die Grinders mis-used in this way are more hazardous than Air driven}

#3 1/4" Die-Grinder with 1/4" "mill-length" drill bit, these are very short, may find them in Cobalt only or Titanium Coated.
Stay away from standard HSS High Speed Steel Bits.
@ 20-30,000 rpm make sure to shield up your arms, chest, all exposed body parts in case of bit breakage.

LH Drill usage, go "slower" than standard speeds, vary up and down, this sometimes will grab the broken fastener.

Does the "Shoulder" of the bolt go fully through the flywheel?

Check the "Fit" between the flywheel and the shoulder OD of the fastener.
Has the gap gotten wider ?

Going back with the larger bolts seems like a good idea if there's enough meat there.

ARP bolts are good for sure, some mfg's of fasteners {Chinese} do not have the consistency of ARP

60 minutes or some other so-called News had a piece on fasteners a few years ago and the Chinese Bolts featured at that time, were inconsistent compared to American Mfg'd bolts. Though to be fair, I do think the Chinese have gotten better at quality control..

I HAVE distributed a few 100,000 bolts in my time at Southern Company and the Grade 5 minimum standard we have implemented on plated std fasteners has eliminated most bolt problems.

Rusty Wrench

Toyota 4AGE Flywheel bolts fit..even come with two spares in a pakc (8 in total. M12x1.25 thread from memory.

aidin, before that damage occured, had you re-fitted used flywheel bolts or brand new non-ARP bolts?

Re-using flywheel bolts is not worth the risk.

I'd say worth it. Here's some pics of the damage.

Talking about flywheel bolts, I seen some ARP flywheel bolts to suit A Series on eBay. The seller states that they are too long and the crank needs to be tapped further. Going by what I read on the thread ARP don't make A series ones so they must be some other car that does suit the A series crank thread. I'm so sh@t with computers I don't know how to put a link up here or post pics for that matter. Oh well they are selling for $50 what do you guys think worth it or not

pulled the motor out yesterday and it wsn't as bad as I thought it could be which is nice. No snapped bolts, they were all about 1mm off holding any tension so the crank and flywheel have exchaned some material. I could have the crank off but I'm going out to a new suburb to help a guy tune his cortina. Will have it off during the week

When you next pull your motor apart, send me down your crank and I will send you up a scalloped 1400 crank.

Jeff builds the motors, Ian bolts on all of his external parts.

Spoke to Ian yesterday, he might be down in Brisbane in the next couple of weeks, I have some parts put aside for him for his new car, if it works out I will give him the crank to take up to your area.

so what grade would i use for a high powered a15 that pulls burnouts almost every day

crikey this thread took off! getting some good info and resolution here. Wouldn't Ian say he gets Jeff Taylor to do it like the Adelaide grenade?(copyright pending on that term of endearment for the classic Adelaide motor) I haven't seen him in a while it'd be nice to catch up and see how he's going. Gary if you recall I bought one of your A14 cranks, in fact I had a small world moment when I noticed you used the same box that PKZ sent you to ship it up here.

Though a lighter one would be nice...swaps?