Re-use stock head bolts on a 6 bolt with only 20K on the bolts?

[Spoolin4Ever]

Someone that helped me do the head last time, didn't clean the threads and so I was getting 60PSI, had to pull the head.

I pulled it myself this time, I want to make sure it stays down this time.

I bought brand new stock head bolts last time we did it, which was 20K miles ago. Can I just re-use these head bolts? What is the proper length on these? I want to measure them.. It's a 6 bolt.

 

[400hp93talon]

Screw that I have always been told not to reuse head bolts, Studs are a different story. The one time I thought I should reuse Head bolts one of them broke when I was torquing it down. I would just spend the little extra money and order a new set or some arp head studs that are like 80 for a set. That is my opinion.

 

[gusu]

Yes, you can reuse them but personally I would not risk it and you really need to check for stretching. As for the measurements im not sure, but google can most likely answer that.

 

[19Eclipse90]

Read this: http://www.dsmtuners.com/forums/newbie-forum/384978-stock-6-bolt-head-studs-strength.html

Make sure the threads in the block are clean before installing anything.

 

[ilikerice]

Can I throw a question in here really quick since we are on the topic of re-using head bolts.

I am about to put my head on my 7Bolt block, just wainting for the M11 1.25 thread chaser to arrive that I ordered to clean out my block threads.

I was going to use the head bolts that I took out. I measured for stretching per Chiltons manual and they are still in spec. Cant even say any stretched at all. After reading this about 6bolt head studs, should I not use these bolts reguardless of the specs.?

 

[19Eclipse90]

If they are within spec, you can re-use them. Most people will tell you not to, but in the end it is entirely up to you. The one thing you should ask yourself is if it's worth saving $30 over.

 

[ilikerice]

good point

 

[Spoolin4Ever]

If they are within spec, you can re-use them. Most people will tell you not to, but in the end it is entirely up to you. The one thing you should ask yourself is if it's worth saving $30 over.

Those are for a 2g. The 1g set is about $80 as far as I know last time when I bought them just 20k miles ago.

Hey they have it for 1g also!
http://www.oreillyauto.com/site/c/d...arch_head+bolt_1205626_3745&keyword=head+bolt

 

[ilikerice]

He read my post correctly. I was referring to my 7bolt. Thanks.

Sorry for the thread hijacking. I just wanted a quick opinion on a similar topic.

 

[burkgonzo]

Come on now, just pick up some new bolts.

 

[99gst_racer]

I was going to use the head bolts that I took out. I measured for stretching per Chiltons manual and they are still in spec. Cant even say any stretched at all. After reading this about 6bolt head studs, should I not use these bolts reguardless of the specs.?

What did you measure them with?


The rule of thumb: 6-bolt bolts are reusable if within spec, 7-bolt bolts are one-time use only.

 

[kchaazz]

While I dont mess with 7 bolt stuff, 1g or 2g, I can comment on this. 2G head bolts are "Torque to Yield" style bolts, which basically means that these must stretch to achieve proper clamping force, thereby rendering them useless if you ever have to remove them. As far as 1G 7 bolt headbolts go, while Im aware these are of smaller diameter vs 6 bolt stuff, I dont know if they are torque to yield or not. I have reused 6 bolt headbolts with 100,000 plus miles on them and didnt have issues. I did not measure them but I did thouroughly clean both the threads on the bolts and the threads in the head before reassembly. Popular Mechanics has a very informative article about all sorts of bolts, discussing torque to yield, vs standard, cleaning threads before reassembling parts and how oils and other comtaminants directly effect clamping force and torque readings. Also, they discuss beam style vs click type torque wrenches and how to properly maintain all of them to achieve reliable, consistent performance. Good read.

 

[brandonwh64]

If you plan on future mods then ARP head studs would be a good choice since you have it pulled apart.

 

[19Eclipse90]

Those are for a 2g. The 1g set is about $80 as far as I know last time when I bought them just 20k miles ago.

Hey they have it for 1g also!
Fel-Pro ES71175 - Head Bolt Set | O'Reilly Auto Parts

All 7-bolts use the same head bolts (MD191470) according to ASA. Looking at the compatibility in your link, it doesn't make sense that a 1990-1991 (6-bolt) head bolt fits a 1993-1994 (7-bolt) engine.

What did you measure them with?


The rule of thumb: 1G bolts are reusable if within spec, 2G bolts are one-time use only.

I agree with slight modification for the reason stated above: 6-bolt head bolts are reusable, 7-bolt head bolts are not.

While I dont mess with 7 bolt stuff, 1g or 2g, I can comment on this. 2G head bolts are "Torque to Yield" style bolts, which basically means that these must stretch to achieve proper clamping force, thereby rendering them useless if you ever have to remove them. As far as 1G 7 bolt headbolts go, while Im aware these are of smaller diameter vs 6 bolt stuff, I dont know if they are torque to yield or not. I have reused 6 bolt headbolts with 100,000 plus miles on them and didnt have issues. I did not measure them but I did thouroughly clean both the threads on the bolts and the threads in the head before reassembly. Popular Mechanics has a very informative article about all sorts of bolts, discussing torque to yield, vs standard, cleaning threads before reassembling parts and how oils and other comtaminants directly effect clamping force and torque readings. Also, they discuss beam style vs click type torque wrenches and how to properly maintain all of them to achieve reliable, consistent performance. Good read.

No doubt something published in Popular Mechanics is a good read; I'd definitely like to see that for my torque wrenches. Paul (99gst_racer) wrote a good intro article on fasteners for this site; there's a link to a discussion thread inside as well if anyone is super interested: http://www.dsmtuners.com/forums/articles-miscellaneous/383565-fastener-tech-101-a.html.

 

[ilikerice]

What did you measure them with?


The rule of thumb: 1G bolts are reusable if within spec, 2G bolts are one-time use only.

I measured with a scale. In the chilton manual they give a measurement what new ones are and min out of tolerance was. I'm at work and dont have it in front of me right now. I only asked ### the manual, people speak so highly of, said this.

It is a TTY bolt and I will be replacing them with OEM bolts. I have no future plans to push this motor beyond stock capabilities. I will be happy if i get 210 Whp and running smooth. If I do decide to go more power, I will simply start another motor and do it with proper upgrades. I just want this car running right now.