Sheered head bolt

[Struggler]

Trying to take the head off, first two bolts came off with some encouragement, but the third has managed to sheer most of the head of the torq head bolt clean off leaving a nub that you can't really get purchase on. Tried another bolt and it has started doing the same thing.

Anyone has this before? Is there a special torx socket that gets on the head of the bolt better? And how have people resolved this in the past?

Gutted as I was making such good progress as the strip down.

 

[Adey.]

drill it off

 

[Struggler]

Yes Sir!!

Ended up having to drill 5 of the f*****s out! Does anyone know of an aftermarket upgrade that will avoid this issue in the future? I guess i dont ever plan on taking the head back off.

 

[Adey.]

I always tap the socket on there a few times and lean on them now. Never used uprated items so cant answer the second question. I'm old school so would pop to a fasteners shop and ask for something of the same size/strength if I was in need. I'm sure you could get some arp bolts though

The Official ARP Web Site | Kits

www.arp-bolts.com

 

[Brigsy]

I think you have been pretty unlucky. I use a bluepoint socket which goes fully on and few taps with a hammer like @Adey. My dci head bolts were tight as fcuk and all came out.

Arp do a stud and nut kit but its expensive and not really necessary on stock 172. Id just purchase a decent snap on, bluepoint or similar high quality etorx socket and use oem or good aftermarket head bolts.

 

[Struggler]

I think you have been pretty unlucky. I use a bluepoint socket which goes fully on and few taps with a hammer like @Adey. My dci head bolts were tight as fcuk and all came out.

Arp do a stud and nut kit but its expensive and not really necessary on stock 172. Id just purchase a decent snap on, bluepoint or similar high quality etorx socket and use oem or good aftermarket head bolts.

Is there a point that they do become necessary??

My comments suggesting I won't take the head off again aged well as I assembled with standard bolts only to have to strip it down again.

I'm looking at the ARP stud kit, it is indeed expensive compared to the standard bolts and I'm not sure what to do. Will be going high comp and high loft cams etc so should perhaps just suck it up and get them...

 

[Touring_Rob]

On some cars the ARP head studs aren't stretch so you need to re torque them after several heat cycles which is a pain - check if thats the case for the FR4 before buying them.

I would personally just get new Renault bolts and a good tool as Brigsy has said, I've personally never seen a failure like that and for it to happen the socket isn't right imo.

 

[Brigsy]

I doubt arp head studs will be necessary on N/A being honest. You can do 500hp on turbo on oem bolts. Re useable is an advantage i guess, if its getting stripped every season.

I was advised by somebody who knows these engines well, that arp head stud/nut on f4r could do with a retorque after a few heat cycles, especially on high boost setups. I havent personally retorqued mine as its too much hassle on f4r due to design. Still running a few thousand miles in.

 

[Struggler]

Thanks, can someone confirm the e-torx size so i can have a look online at options.