91Honda_gsr

New build gsr built bottom end with b16 head gsr cams..
Ok so I broke a cam cap bolt decided to buy a new Oem set, after I got them I put them in snugged all of them down lubed with 10-30. started the torque sequence and snap brand new Oem bolt... I have my wrench set at 19.7ftlbs

So thinking it was my torque wrench, I took an old bolt put it in the vice and turned on it it went straight to 20ftlbs without twisting the bolt same results with my other torque wrench.. I'm lost as to what's causing this problem. Some torqued down fine the first time before I broke a bolt when I did this last week. Some where clearly stretched and some looked fine.. I'm now at the point where I'm afraid to try again for fear of breaking yet another bolt. Could it be to much lube? I didn't use that much just dipped maybe a 1/4 of the bolt in oil tapped off th excess and and threaded them down idk what else it could be but iv used the same method multiple times without problem.
Thanks for any input

civic-steve-94

Well from what I can find the spec for the 8x1.25 bolts is 17lb-ft and for the 6x1.00 bolts is 7lb-ft. I have never had this problem, so just make sure the cams are in a natural position and rocker adjuster are back out all the way.

91Honda_gsr

I made sure the cams sat naturally I will use those torques and if it goes smooth I'll use that, I'll back off the adjusters but I haven't had to before I also switched the valves and didn't think about it so it maybe the problem I'll check it maybe later tonight defiantly tomorrow and get back thanks man

cruizinmax

iTrader: (2)

20lb/ft is not very tight at all. You can easily do that with a normal length 3/8" ratchet. If you are trying to torque it with a long torque wrench that is most likely your problem.

civic-steve-94

It should not matter how long the torque wrench is if it's calibrated correctly

blackeg

i think some of the newer b series bolts had some occasional issues breaking. i feel like the solution was to lower the tq to 16 or 17 ftlbs as mentioned.

make sure you are following the proper sequence and and using 2 steps with the second step having a larger tq increase than the first step.

civic-steve-94

I found something interesting, I was floating around on alldata look at these specs again and on a 95 delsol with a b16a3 it's 17lb-ft and on a 00 civic si with a b16a2 it's 20. So I when onto majestic Honda to see if the bolts were a different part number and they aren't. That's kinda strange to me.

PyroProblem

Interesting...

PyroProblem

Someone should use a bolt stretch gauge and take some measurements at different torque values increasing up to the point of failure.

2kdrift

This sounds like an torque wrench error, as stated earlier use the appropriate size. Click style torque wrenches are not accurate and the lower end of the spectrum. i.e a wrench that is capable up to 150 ft/lbs will not be very accurate at 20 lbs.

Your gonna want to use a 3/8th drive torque wrench for this

civic-steve-94

You are correct, I should have been more specific with my reply. The right torque wrench for the application is very important. In my opinion for something like this a beam style torque wrench would be best, most of them are made for relatively low torque values.