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Does anyone know if the 8 valve 4g15 in my excel (g4dj) used torque to yield bolts on the head or rod / mains?

i cant really afford a set of ARP's, so is it really unwise to reuse the head bolts and especially main and rod bolts??

thanks
Dan

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-91 hyundai excel g4dj->
fully rebuilt, 0.5mm o/s, balanced
diy port & polish,
p&p tb, testpipe

Head bolts you should never reuse; especially in boosted app's. Main bolts are fine, rod bolts arefine - check for stretch using a guide from ARP (?). If you boost any engine in the upper ranges, then ARP head studs are a must to hold things tight, period. I realise you are n/a so don't worry yourself with the boost part.

Most head bolts seem to be TTY but even if they aren't would you want to chance your gasket any more because you didn't want to shell out for new bolts?

i thought someone else on this site said that the hex head bolts were ok to use again. maybe i need to talk to the dealer and see if they know.

AUD 110 seems a bit pricy for 10 head bolts, dont you think?

Also, does anyone know where to get info on the thread measurements??

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-91 hyundai excel g4dj->
fully rebuilt, 0.5mm o/s, balanced
diy port & polish,
p&p tb, testpipe

110 AUD is pretty pricy I seem to remember paying 8$ a bolt x10 bolts CAN, but shipping to mainland Australia is maybe what is getting you plus dealer markup may be higher where you are.

Some bolts (Hex head or otherwise) can be reused) but only if they are not Torque To Yield type bolts. The torque to yield bolts are stretched to achieve their maximum strength and once used like that they are going beyond that ideal zone if stretched any further (IE they snap!). Some people have reused their 4g15 12/8V head bolts but they have just been very lucky that they have not had any problems yet. The bolts for your application are TTY type. Would you chance blowing a gasket when you can least afford it. Not like this time is much better but at least you know what to do about it right now. Best not to worry about it and get it sorted, right proper fashion.

I have reused the head bolts on 4G15s before (sometimes more than once) and had zero problems. Just dont overtorque them.

PS - I think you will find that an ARP stud kit is actually a little cheaper than stock dealer prices. Talk to RPW about getting the right kit for your 4G15 if you decide to go down that route.

Alright guys, i went to the dealer here yesterday, and they sell a set of 10 head bolts for AUD 66. I also asked them if the head bolts are TTY, and they said that they are not.

According to them, (and backed up on hmaservice.com) hyundai started using the torque angle method on their critical fasteners (head, rod and mains etc) in about 1997.

hmaservice.com has a service bulletin that indicates that most of the post 1997 torque angle bolts are re-useable anyway.

This makes sense to me, because i was under the impression that in order to use the stretch method (TTY) you have to be able to measure the length of the bolts after they have been tightened, and i was wondering how you can do this with head bolts or main bolts?? obviously you can do this with rod bolts.

i couldnt say if this applies to the mitsubishi 4g15 or not, but this is the information i have to hand.

PS: feel free to correct me on any of the above.

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-91 hyundai excel g4dj->
fully rebuilt, 0.5mm o/s, balanced
diy port & polish,
p&p tb, testpipe

hmmms $66AUD is pretty cheap. I dont think you would get an ARP kit for less than that on second thought.

Good info!

Well if people have had good experiences with reusing their bolts the more power to them. I must be a little stubborn when it comes to reusing some (of what I consider) critical parts such as the head bolts when tightening them again.

Ive reused my head bolts. So far so good. I torqued in about 6 steps. I also rechecked torque after running enginge and cooling down. Torque stayed the same.

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http://members.cardomain.com/socrateez
04' Olds Alero
91' Colt GL hatchback
4g15 12valve 5spd.
4g37 TB, MAF & Injectors. 4g37 ECU
Ported & polished & custom CAI w/K&N filter
5* Cam retard, 7*Ignition advance
2-1/4" catback w/flowmaster muffler
89 GT brake and suspension swap
Lots of little s#@t

Mine broke after a few weeks,but i put about 700 miles on them each week for work......when in doubt,buy them new.....

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http://groups.msn.com/KR2NZc-c- <<<I GOT SOME $$$ COMING DUE TO A WORK RELATED INJURY...SO IM GETTING A GARRAGE,AND LOTS OF CSM STUFF SOON!!!!

It's all about chance. You have a bigger chance of a bolt breaking and having a huge problem/mess on your hands if you reuse the bolts than if you bought them new. Cheap insurance.

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Had a:
1991 Eagle Summit ES Hatchback - 4g15 12v 5spd
1991 Dodge Colt -4g15 12v 4spd
Have a:
1978 Oldsmobile Cutlass - 468BBO TH350
Round 3:
1990 Dodge Colt-4G63T 5spd

yeah, i'd rather pay 90 bucks for some ARP head studs than god knows how much if one or more were to break...

ive reused head studs as well without badness happening.

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2000 Mirage RPW coupe. Too many mods.

I've reused on mitsus without issues. however VW different story they are a throw away EVERY time...

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LC '01 Accent GSI - Silver
MC '07 Accent GSR - Midnight Gray
C52A '91 Colt 4G64DOHC N/A Lots of Mods - White

mine turned out to be pretty damn cheap anyway, seeing as the dumb guy at the parts shop only charged me for 1 bolt instead of 10!! nice $6.5 set of oem head bolts

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-91 hyundai excel g4dj->
fully rebuilt, 0.5mm o/s, balanced
diy port & polish,
p&p tb, testpipe