okay guys, i'm going to put my time up for this one. for a little background, my name is Jason and i work for the Mechanical Engineering Dept. of the College of Engineering at the University of South Florida in Tampa, Florida. as such, i have access to many neat toys that most people only see in photographs.

now, for the test items:
i will soon have a stock, used headbolt (actually 10 of them) from a '95 LS that has been torqued once at the factory and a second time by me. i didn't retorque it after i installed it the second time, and in 10k miles i haven't noticed any problems with sealing. i will also have a used headbolt from a '98 JDM B20B that has only been torqued once at the factory and never again.
i would like to see somebody or somebodies donate the following for testing:
<FONT COLOR="blue">1 NEW ARP head stud for B-series. length/application does not matter as stress does not depend on length, although it would be nice to have the same LS/B20 non-VTEC application to minimize variables.</FONT>
<FONT COLOR="red">1 USED ARP head stud for the same.</FONT>
<FONT COLOR="green">1 NEW OEM Honda/Acura head stud for the same.</FONT>
i will be using the short bolts, not one of the 2 longer ones, for the test.

the test:
i hve access to a tensile load machine, and i will proceed to test each head bolt i have in the same machine with the same ambient temperature and pressure. i will thereby derive the stress vs. strain curves for each bolt/stud. i will compare them to each other, and compare the yield stress of each with the others to determine the following:
1) are stock headbolts that have been reused weaker than new ones? if so, by how much, and what are the implications of this difference?
2) how much better are ARP studs over new stock and reused stock ones?

i intend to answer these questions and more through this experiment. please people find it in your hearts to either donate a bolt/stud i don't have available for testing or donate the $15-$20 it would cost to buy one. i know somebody has to have one lying around, or at least have $15 and an interest in this age-old question.

 

BTW, you can reach me by PM or by email: theantiles@aol.com to please donate.

 

Good idea. Thanks, though I have no headbolts.

 

we'll get it together Jason, hit those up I told you about...

 

It was my understanding that there are two different types of OEM headbolts? One type is okay to reuse and the other is not?

 

awesome. IMO i know its not talked about on the allmotor forum much, but i KNOW ppl running sohc boosted motors would be very interested in the results for a d series as well


i got some headbolts i can send, from a b16, but i have no clue to the "condition" of them as they all came out of jdm motors

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EKhatch &raquo;</TD></TR><TR><TD CLASS="quote">It was my understanding that there are two different types of OEM headbolts? One type is okay to reuse and the other is not? </TD></TR></TABLE>
can somebody please fill me in on this? this information would be very helpful to this experiment!

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by johnzm &raquo;</TD></TR><TR><TD CLASS="quote">awesome. IMO i know its not talked about on the allmotor forum much, but i KNOW ppl running sohc boosted motors would be very interested in the results for a d series as well
i got some headbolts i can send, from a b16, but i have no clue to the "condition" of them as they all came out of jdm motors</TD></TR></TABLE>
well, if somebody wants to supply me with D-series parts, i'll be happy to oblige a test for d-series parts as well. actually the test will cost a bit to run because of actually buying the strain gauges and such, but i'll check with the guy, Patrick, who runs the lab with the tensile load machine and see if he can hook me up. if it's not too expensive i'll pay for the straing gauges, as they aren't reuseable. if i remember correctly they're like $5/pop or something, so not too bad. maybe he'll give me some for free . if he doesn't maybe a nice person will donate a little money to the project, or split the costs with me. as for d-series test, i really don't want to pay for a second round of tests myself. i'll talk to patrick ASAP about it and get back to everyone.

if you're going to donate head bolts/studs, please be sure of their condition. it is vital to the test.

 

mmm MSE. subscribing.

 

i think u can definitely use ur head bolts..i mean, ive used mine after i replaced the headgasket...the has been runing without any issue or anything...but if u dont mind spending and buying another set, then its much safer because i heard that those stock head bolts tend to get stretch out over a time

 

I have a set of used ARP's, i can send you one if you like. PM me.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by smkngsr &raquo;</TD></TR><TR><TD CLASS="quote">i think u can definitely use ur head bolts..i mean, ive used mine after i replaced the headgasket...the has been runing without any issue or anything...but if u dont mind spending and buying another set, then its much safer because i heard that those stock head bolts tend to get stretch out over a time</TD></TR></TABLE>
well, this experiment will test exactly how much weaker (if any) stock head bolts are after being used versus when they are new. if they are not significantly weaker, it will disspell(sp?) the myth. if they are, it will provide quantifiable proof of why not to reuse them except in the tightest of pinches.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LsVtec92Hatch &raquo;</TD></TR><TR><TD CLASS="quote">I have a set of used ARP's, i can send you one if you like. PM me.</TD></TR></TABLE>
thank you! you have PM, sir.

i guess technically if i want this to be the end all be all of experiments, i should test more than one of each. but first i'll collect measurements from 1 sample of each, and i'll go from there. i'll also have to see how many people are willing to give up a bolt and/or stud for this. i'm not sure how far i'm going to stretch them, but i can more or less garauntee that the bolts and studs i use will not be suitable for a car. i will probably stretch them until they all break, so that i can have a nice graph for each.

 

I had a used set of b16 head bolts that I re-installed numerous times due to headwork, bottomend work, etc. Never any sealing problems and they always torqued nice and crisp.

 

b series honda bolts are not stretch bolts therfore they can be used again if they where stretch bolts like on volkswagons and other german cars then you would not be able to use them again and would need to replace them everytime the head where o come off

 

I pulled the head on my 92 RS when it hydro-locked to replace a bent rod. This was with 253K miles and I reused the head bolts when it went back together. Actually, I reused the old headgasket too, and I have had zero problems with over 282K miles now. All praise the B series engines!! Ok, I'm lucky.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EKhatch &raquo;</TD></TR><TR><TD CLASS="quote">It was my understanding that there are two different types of OEM headbolts? One type is okay to reuse and the other is not? </TD></TR></TABLE>

You talking about conventional bolts and "torque to yield" bolts.Torque to yield take a permanent set and can't be reused.
Glenn

 

well if you're saying you'd rather not do the research then okay, but i'm going to do it anyways. i'd much rather do the experiment and find out that the stress/strain curve is identical for new and old/reused head bolts and to guess it's okay just because we think it will unload perfectly elastically. this way we have quantifiable proof, not just "i reused mine and they were fine". i did reuse mine, and they were fine, but as a scientist i'd rather have quantifiable proof.

 

Damn, my pile of headbolts is all D-Series, but interested to see the results none the less.

Edwin - Student of Mechanical Engineering / University of Miami

 

How about a test on various rod bolts? Rod bolts see much more abuse and stress cycles than headbolts/studs and it would be nice to have a big comparison chart. I would imagine that people have a lot of those lying around new and used from all sorts of engines (B, F, H, K)... I could donate new and used H22, F23 and K20A3 rod bolts for that test...

Pirate

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dr_latino999 &raquo;</TD></TR><TR><TD CLASS="quote">Damn, my pile of headbolts is all D-Series, but interested to see the results none the less.

Edwin - Student of Mechanical Engineering / University of Miami</TD></TR></TABLE>
well i may be able to test those, too. like i said, i don't want to spend a bunch of money on this project as i'm a friggin' poor college student, but i'll see how much the strain gauges cost. if you supply the bolts it would go a long ways towards being able to compare the strength with new, used, aftermarket D-series as well as compare them to the B-series parts.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PirateMcFred &raquo;</TD></TR><TR><TD CLASS="quote">How about a test on various rod bolts? Rod bolts see much more abuse and stress cycles than headbolts/studs and it would be nice to have a big comparison chart. I would imagine that people have a lot of those lying around new and used from all sorts of engines (B, F, H, K)... I could donate new and used H22, F23 and K20A3 rod bolts for that test...

Pirate</TD></TR></TABLE>
i'm sure this would be a good test also, and rod bolts are not as thick and therefore would be easier on the machine, too. i'll look into testing rod bolts, but once again, i don't have $100 to buy a mess of strain gauges, so i'm not looking to go all out testing everything i can get my hands on. unless the Department will cover the gauges (as in, notice they're ALL missing and buy some more ) . . .

 

I know for a fact b series Honda motors you can re use stock head bolts. UNLESS the threads look worn or stretched. With new bolts you're suppose to torque them to a specific number to break them in then loosen them and re torque to the actual spec. When they're used u just torque them to spec And that's it. I have the all data engine overhaul for a b18c1 and that's what it says.

 

Nice 15 year bump on this one.....