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I am pulling apart my engine to fix a blown piston ring and will need to remove my head bolts. Does anyone know if I will need to purchase new head bolts to put on or if I can re-use the old ones, also does anyone know how tight I will need to torque them? Thank You!!!:thumbup:
 

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I don't know about bikes, but I'm sure it's the same as cars.. I had a Honda CRX that blew a timing belt and the 'shade tree' mechanic I let work on it reused the head bolts... not 500 miles later, I blew a head gasket because the 'torque specs' had changed because of stretched head bolts... I learned you change the head bolts every time you take them out.
 

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Head bolts on cars are not reusable. Would make sense if its the same on a bike.
 

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local dealer

I am pulling apart my engine to fix a blown piston ring and will need to remove my head bolts. Does anyone know if I will need to purchase new head bolts to put on or if I can re-use the old ones, also does anyone know how tight I will need to torque them? Thank You!!!:thumbup:
just curious - do you have a good suzuki dealer in your neighborhood? if so, i would utilize them as a local resource, especially if the situation warrants it quickly. our dealer here is great and are always helpful and willing to provide the technical insights and tricks to the trade. i am no mechanic for sure, but if it were me, i may consider replacing them if it seems that could have remotely took a beating in the process.

just a thought. good luck with your weekend job. :)
 

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I've done 20 plus rebuilds, and the only time I used new head bolts was when I put the spacer plate on the turbo busa. But the best advice I can give you is to GO GET A SERVICE manual BEFORE you start working on a project like that. You think you are just going to replace a blown piston ring and call it a day? IF it is a ring problem, you now have a cylinder surface issue, as well as a scored piston problem. So say that tye cylinder is somehow perfect as well as the piston (which it's not going to be) You replace just the "blown" ring and start to put it back together...Oh man, how do I put the cams back in and get the timing correct? :infrandom
 

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Discussion Starter #8
Yeah I know this won't be an easy task... I will be doing more than replacing the piston ring, I purchased this bike for 1000 dollars with three engines. I got the clymers guide with it. I have taken the head off of car engines and other smaller motorcycle engines before, and some I had to replace and some I did not, So I was unsure about the GSXR... Thanks a million for all of your responses!:D
 

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All bolts stretch when they are tightened and then relax when they are loosened. It’s just like stretching a rubber band and then releasing it. The pressure it has against whatever is in between the head of the bolt and whatever the threads are in is under “clamping force” due to the stretch of the bolt. In your case this would be the cylinder head and gasket. Think about the rubber band again. Every time you stretch it the band gets a little longer and every time you relax it the band stays a little bit more stretched out until finally it is too stretched out to apply “clamping force” to whatever it is around or it finally breaks. Bolts work the same way. Most engines now use torque angle to measure the clamping force when the bolt is tightened instead of just a torque measurement. This allows the bolt to be stretched more accurately. Most bolts are not recommended to be reused anymore so this clamping force can be more accurate and even on an application where a bolt can be reused where do you draw the line on how many times you feel safe reusing it. Twice? Ten times? A thousand times? If it were a tail lamp bolt who cares but a rod, main or head bolt most often you would not want to risk failure. Also keep in mind that when you tighten a bolt it distorts all the things around the bolt. In your case the cylinder wall and head surface can be distorted by improperly torque bolts. It gets kind of complicated when you start considering that some machine work should be done with simulated torque applied to correct for this distortion.
 

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Discussion Starter #10
Hey Guys... Turns out I don't have a blown piston ring... at least not in that engine:bounce . I had three engines when I bought my new bike, and a compression test showed me that the blown piston ring the seller told me about was in a different engine than the one I'm putting in the bike... Thanks for all your responses!
 

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Hey Bowtie,

I like the rubber band analogy but that's only half the story. Bolts (and metal in general) have two strength ratings; Elasticity and Plasticity. If a bolt is torqued within its elasticity range and does not reach its plasticity range, it will be reusable.
Give the size of the bolts on this bike and the strength of the aluminum head, it's doubtful that the spec would put the bolts into the plasticity range. Bolt stretch is usually a issue when a bolt is used to compress steel in a tension joint like in a rod bolt.

That said, the factory manual is the final word on the subject.

Check out this book for good general information on bolt strength.
http://www.amazon.com/High-Performance-Hardware-Technology-Enthusiasts/dp/1557883041/ref=sr_1_1?ie=UTF8&s=books&qid=1196108013&sr=8-1

-Jonah
 

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You are absolutely correct Fastmonky591. It gets kind of complicated when you start thinking of metallurgy, machining tolerances, distortion, thermal cycles, expansion rate of different alloys, etc…. I thought for a long time that all you had to worry about was leaving it loose or cross treading it. I guess that’s why engineers get paid the big bucks and all I have to do is red the book and do what I’m told.
 

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if im not mistaken there are torque to yeild bolts (the ones you can only use once then theyre trash) and theres reuseable bolts. i cant remember if torque to yeild bolts have any special designation on them
 
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