How may times can head bolts be reused? I have not run into this before got my rebuilt heads back and trying to put my motor back together. I have taped all holes and cleaned and die all the bolts. I can take all bolts to the first torque 60#s and cannot get to 85#s without breaking or stretching the bolts. All holes are dry and the bolts. The manual says to dip in oil. Well I did on my first go and broke one going to the final torque. So what is going on??? Torque wrench is dead on.

 

No idea. That's not normal behavior.

There is no specific limit on how many times you can reuse head bolts - it's essentially indefinite.

You said the holes were dry, and then you said that they were oiled - which was it, and did you actually fill the holes with oil, or did you dip the bolts?

- Eric

 

I dip the bolts in oil and the holes are clean and dry. I went by the manual. This is a first for me, never had a problem like this before.

 

Maybe a previous owner drastically over torqued them?

- Eric

 

I am by no means an expert, so take this as a question:

Is it possible that there is too much oil on the bolt, and it seals the bolt-hole, pressurizing the cavity below the bolt? Could this compressed air, with the oil "seal," prevent the bolt from seating fully?

 

All the heads I have done in the past have been torqued with clean and dry bolts and holes. This is a first for me useing oil on the bolts only. And these had a light coat to prevent hydraulic lock.

 

The bolts shouldn't be anywhere near snapping with only 85 FT Lbs of torque on them. Something is up with them for sure.

 

That's what I feel l am totally puzzled. I'm using Felpro gaskets also and have never had this problem. I'm at WTF over????

 

Is your torque wrench up to date?

try a diff torque wrench.

Arp head bolts.

Gene

 

I would suspect a wrench problem.

 

AJ says in his first post: "Torque wrench is dead on."

(Though he doesn't say how he knows...)

- Eric

 

Calibrate wrench.....get new bolts.

 

Ok wrench checks on a anylizer. Today I went thru the whole process. Checked and cleaned all threads. Put a light cost of oil on the bolts only. Torqued just fine to 60 ft#s. When I go to 80 I get about an 1/8 turn and these bolts are going into a hydraulic lock feeling. And I'm stretching the bolt right at the mating surfaces. This is just not right. I have tried this process with the bolts and holes dry and they do the same thing.

 

The only time I broke an Olds head bolt or any head bolt for that matter, was when I used a non hardened washer under it. I used them thinking the 7/16" bolts going through 5A heads, which had 1/2" head bolts originally, that washers would help. I thought they might bite better with washers, I was wrong.

 

Maybe they're not the proper original bolts.

- Eric

 

This sure sounds like the problem. Unfortunately, once you have too much oil down in the bolt holes, it will be difficult to get it out. You don't need much on the bolts, just a light coating.

 

If the threads were just dipped, there is no way it would be enough. Even if the hole bolt was submerged, that is questionable. Get a different torque wrench. I bought another wrench to check mine, both were very close.

 

buy new bolts I wouldnt trust any of them at this point.

 

Unless you are a stickler for OEM bolts, get ARP studs, and use ARP lube. You no longer have the threads in the block turning and causing friction, or locking.


Depending on how much the heads were milled, your heads may be thinner than the original ones, and the bolts may be bottoming out.

 

Are there washers under the bolt head? Are the threads bottoming out on the deck surface?

 

Thank you Joe for chiming I was hoping you where following. And for everyone else your input has been taken in knowledge learned. Thank you!


These are the measures I am going to. I have went through every hole and cleaned tapped and sprayed WD40 in each hole and blown out all excess oil leaving a very light coat. I have run a good head bolt in each hole until it bottoms out (this is without the heads on) to watch for any air trapped (none). I am buying new bolts, going with stock bolts from In-Line Tube.


Here are my questions about dipping in oil. What type? What is considered a light coat? I am really gun shy about this beings I'm putting out another $100 bucks for such a simple task. This oil dipping a head bolt I have never had to do before, but this is my first Olds 350 overhaul and using 7/16" bolts.


When I torque, do I still go to the first 60# on everything then to #80 or #85? The manual says #85, every where else I have looked and info gotten off this forum says #80.

 

Dip the bolts in any normal motor oil.

If you let them drip a minute, or blot them briefly with a rag it should be the right amount.

I'm surprised you've never done this before - it's been my impression that most head bolts are torqued wet.

When you torque, you torque all bolts in order to the first stage, then the second, then the third.
80 or 85 foot-pounds doesn't matter, as the margin of error of your torque wrench is probably more than 5%. I'd go with what the CSM says.

- Eric

 

Thanks Eric


All of the heads I've worked with have been Fords. they have ether been cleaned die bolts and re-tapped the block threads the only oil was very little from the cleaning process no dipping. Or torqued to yields with new bolts of course.
I'm just glad I have you folks to help me through this.

 

If you reach the correct torque level on your bolts, you WILL feel them stretch. That's what ensures they stay tight, just like rod and main bolts/studs. With ARP studs, you get more threads in the block, and the stud can stretch without applying more pressure on the threads in the block, which is where your bolts are likely breaking. When you clean the threads in the block, you should use a thread chaser, not a tap. This will clean and roll the threads as opposed to changing the cut of the threads, which can gall and cause binding. At this point, ARP studs would be a better choice than a new set of bolts. I have seen plenty of replacement bolts that can't take the torque.

 

Hi,

I had the same issue with only 1 bolt, (1965 330)

I couldn't figure it out for the life of me, I ended up getting it to 72-75ft/lbs and called it good, I now have 3 torque wrenches, even a old style lever one and all showed the same value. Any tighter I could feel the bolt distort and break (like 5 of them)

In my 65 manual it calls for 80 ft/lbs though on the internet everyonesays 85, even in a few build books called for the 85.

I used the bolts from Inline Tube as well, I also put a grade 8 washer under my problem bolt to make sure it wasn't being side loaded. My heads weren't machined as it only had 50,000 just lapped the valves.

You didn't mention if you had the heads resurfaced but maybe they didn't get the flat to the bolt surface or perpendicular to the centerline of the bolts? That might explain what you have going on.

Good luck with it.

Regards,

 

I want to thank everyone for contributing and it has made me go back to the beginning and retrace all the steps needed to accomplish this task.


I FEEL LIKE AN IDIOT! however from failure comes success.


My new bolts are on there way and while waiting I have done a through inspection of the entire process and I have found the problem. "TORQUE WENCH" Yes I said that it was checked and good that was done about a year ago when I started this restoration project. As I was going over everything and looked at it on the bench and I noticed that something was different about it. I have an old PROTO there was a hole and the cover/cap was missing. This must be the calibration screw? nothing in the hole. So I took it over to the College auto shop and put it on a digital analyzer. Sure enough it was out by 25 ft. lbs. and of course to the heavy. So I gave it a proper burial in the garbage, went and bought me a good Craftsman took it back to the College and tested it and its around .1 to .3 off.


So I just wanted to make this clear so this thread can help someone else not make the same mistakes I did thinking that you have everything good even the smallest thing can make you look STUPID!
MORAL OF THE STORY...........CHECK YOUR TOOLS FIRST! IF YOU DO THIS AT HOME!


I want to thank everyone and I want to apologize for the goose chase. Everyone had a valid answer to my problem. I am an Inspector by trade maybe I need to bring work home more often.


I'll let you all know how this ends after the heads are on.

 

A fine lesson for all of us.

Glad you got it figured out!

And, as had been noted many times before: It's always something simple.

- Eric

 

Thanks for sharing your new-found knowledge and sage advice! Bummer the lesson cost more than a few pennies and likely encouraged a few hair follicles to jump ship , though...

 

X2 could not have said it better.

 

I'm sure before this restoration is complete I won't need a full hair cut anymore.


"Just a light trim please" (I'm restoring a classic) LOL!

 

Most will fall out on its own anyway, don't ask me how I know.

 

I agree with the above posts! Thanks for letting us know what you found - very valuable to all of us! Not so long ago I bough the Snap-On digital torque wrench so I can handle the torque-to-yield bolts, and mostly because I was able to talk to the guy who recalibrates all of Snap-On torque wrenches. He said he hasn't had to recalibrate a single one since they started making them. That's the kind of reliability you have to pay for however. What's cool is that you can watch the bolt stretch as the torque numbers hold steady while you tighten the bolts. Its a quick way to learn when to stop pulling on the wrench.

 

I just want to caution that if you're 'feeling the bolt stretch' you've gone to far already. It's time for a new bolt. There is no way anyone is that calibrated to feel a bolt give a few thousandths of an inch.

 

Quite a few old school mechanics can "Do up a bolt properly" to surprisingly accurate figures.
I can't, but some of my former mentors could.

Roger.

 

Maybe "feel" is the wrong way of stating it. You can pull the wrench, watch the torque figures stay the same, or increase at a much slower rate. I'll try to film what I mean when I torque my heads down next week and post a Youtube video.

 

Got new bolts, new torque wrench and everything went as planned. As you see it looks Marvelous.


Thanks everyone for your help and input.

 

Now that is a beautiful sight! And a Happy Ending!

 

Haha!! I guess you get the classic restore trim where needed as well.