Head gasket??

[Guest]

I would. I was told a long time ago the a bole only needs it's dia threaded in to hold properly. I don't know if that's true or not. It makes sense, as most nuts are only as tall as the bolt is in dia.

 

[bigjones]

Well you are not going to freaking believe this.

I backed the nuts out slightly so they would be at least flush with the nuts. Started torquing down, got to 46 Ft-lbs and #1 stud gave out a big crack. Thinking my torque wrench had some how broke, I got out another torque wrench and I was on #8 and it gave out a crack and got loose.

Pulled the poxy head back off again. #1 and 8, were the only studs that I could not turn with my fingers. I got #8 out OK by double-nutting:

Any ideas?

Here's photo with the threads cleaned up a bit and the bits I pulled out the hole:

The stud hole looks stripped as well - should I run a tap down there to clean up and then see how much thread is left?

 

[Guest]

If you have a clicker type wrench and it has been stored "loaded", i.e not set to zero, that will throw the wrench out of calibration and your readings off.

Bro, you got serious problem. Nothing that can't be solved with heili coils.
The new problem is you only really have one shot to fix it and the holes need to be drilled perfect.

If it we me, I'd have two options:

A. use the head as a guide to drill the holes and hope I got it right.

B. pull the motor and bring it to a machine shop and have them do it.

Hap will be along shortly and will give you better direction. Cleaning out the hole is a moot point now, you don't have any threads left to clean.

This may have happened when you tightened the studs in the block.

IIWM, I wouldn't use those studs, I'd get another set. (after I had the block fixed.

The good news is, it's good it happened now. Once you fired it up and it got warm, they would have unloaded.

 

[bigjones]

Kellysguy,

Thanks for the reply.

I cleaned up the threads in the block and I could run a bolt down there.

Are you saying though that, once "unloaded" (when the stud pulled away when I torqued it down) they can't be relied upon to hold a stud anymore. And they now need to drilled for helicoils?

Jeez, this is bad.

 

[Guest]

Unloaded is an engineering term meaning that they ( the threads in this case) simply failed. You "load" when you tighten, it stays loaded until you undo the fastener or something fails. In this case, it appears they were (studs) overtightened when they were placed in the block.


Relax, anyone who doesn't strip bolts, nuts ot threads now has done it in the past SEVERAL TIMES. It's allot like tuning a guitar, there is a spot where it's tight enough and only way to learn is to go under and beyond that point. I have stripped so much stuff, I can get a fastener to just start to strip, but still hold. It'll hold fine till you undo it, then it won't go back again and hold. First thing we learned in auto tech school was to drill and tap holes.....for a reason. I've always felt they should have taught how to feel a bolt stripping, but I was already beyond that point by then. When resistance plateaus, you're already in trouble.

Yes, it's not good but it's not the end of the world. This happens all the time with 396 BBC's in the MAIN CAPS !!!!

You might not need to do all of them, just the blind ones IMO. No way to tell for sure w/o looking at them (holes and studs).

PM or shout out to Hap.

Don't feel bad, strip happens. ( now this may be from someone overtightening them before, thus the stripping nuts and blow gasket.)

Rest assured that at some point in time they were overtightened. If you did as Jack suggested, it wasn't your fault. Just snug is fine and maybe back out two turns is fine. I wonder about your torque wrench though. I seriously doubt what you have left will hold. This isn't repairible with form-a-thread either. Next step is get with Hap.

 

[bigjones]

Thanks for the words Kellysguy. I can't tell you how bad I feel about this.

I installed the studs until I felt them just bottoming out. No additional tightening whatsoever. Then I backed them out a full 2 turns. I really took my time over that to get it spot on.

I have a feeling you are right about the torque wrench - but for 2 torque wrenches to be seriously out of calibration is cruel. I must admit I know about the slackening off after use but sometimes I forget.

In cleaning out the 2 holes, I have uncovered more thread that I do not believe has been used previously by the studs - and there is still a bit more to go before the actual bottom of the hole.

I have a feeling (hope springs eternal) that new studs may hold. I'm certainly willing to give it a go. I'll put in the Payen gasket that came out undamaged in the attempt before last. The studs will all be loose and then, with the head on, I'll tighten the studs down until, either they are a snug fit, or they are level with one nut (and washer) height, whichever comes first. Then I'll torque them down - with a NEW FREAKING TORQUE WRENCH!!! If the studs hold, after firing the engine up, I will tear it down and put in a new gasket. Does that sound like a plan - or another dumb move?

PS Anyone got a recommendation for decent torque wrench?

Cheers!

 

[Guest]

If the studs hold, after firing the engine up, I will tear it down and put in a new gasket. Does that sound like a plan - or another dumb move?

Let's think about this for a moment. If the studs hold....how will you know, by the used gasket not leaking? So... if it leaks...is it the used gasket or the studs?

The block threads are marginal to begin with; rememeber what I said about only being able to go together once? Why chance it? If this indeeed is your plan, use a new gasket and studs and LEAVE IT BE if it works.

Another thought, say it works....for now, when it runs warm again, "pop goes the weasel". (maybe)

IF...and only if, you have enough GOOD threads in the block as much as the nut is tall, AND....a new gasket....AND you don't keep pulling it back apart, MAYBE....just maybe..it'll hold. (with new studs of course)

If it doesn't hold, you're out your new studs (however many you change) and a new gasket. You 'll need those again as well as heili coils and a possible a machine shop bill.

Remember, never enough time and money to do it right, but always enough time and money to do it twice.


Above all, DON'T FEEL BAD !!!! Strip happens.

I would think a stored-loaded torque wrench would read under, not over. I think it came in this way. It's not your fault, so don't feel bad. It's just one of those things that happens some times....just this time it's happening to you.


Maybe this is an attractive lady friend, and bigjones wants an excuse for her comming over, 'eh??? :wink:

 

[dklawson]

Sorry to hear about all this Adrian.

I have no recommendations for locally available quality torque wrenches but I do have a suggestion for you that may allow you to use the torque wrench you have.

Take your wrench and bathroom scale to the garage. Have your Mrs. join you. Put a wrap of tape around the handle of the torque wrench exactly two feet from the center of its square drive. Put the bathroom scale next to your vise, set the wrench to the torque value you need for the head gasket, then clamp the wrench's square drive in your vice. Stand on the scale and have your wife write down the reading (your weight). Now (while standing on the scale) slowly, steadily pull up on the wrench (ON THE TAPE MARK) until the wrench clicks. Have your wife watch the bathroom scale and record the scale's reading when the wrench clicks. Repeat this a half dozen times and average the readings. Subtract your initial weight reading from the average. And finally, multiply that value by two (2) since you were pulling on the wrench at the 2 foot mark. Compare that to the value you set on the torque wrench and you'll have a good idea how accurate (or inaccurate) your wrench is. Armed with that you can set your wrench accordingly.

If you decide to HeliCoil the block, I think Advance Auto carries the kits. I'm sure there are other local sources.

 

[Guest]

Doug, you have more faith in a Chinese bathroom scale tan I do!!!

Mine always tells me I'm gaining weight, so I ~KNOW~ it's gotta be off....

 

[dklawson]

I have a 25+ year old "made in the USA" scale. Regardless of where it is made, the principle isn't that the scale is accurate relative to zero but that it is "accurate enough" within a 20 to 30 pound range above what an average person weighs.

BTW, I've decided I'm not overweight, I'm just short.

 

[Guest]

Accurate enough?!?!?!?!?

Dude, I don't mind it if it reads 20-30 LOW !!!!

 

[bigjones]

if it leaks...is it the used gasket or the studs?

Well, I was thinking if the studs fail, the nuts would become relatively loose again. But you've convinced me - if I'm going to give it a last shot I might as well put in a new gasket.

Maybe this is an attractive lady friend, and bigjones wants an excuse for her comming over, 'eh??? :wink:

Ha! You forget I'm a geezer and this is about the only thing that interests me:

Doug, my friend, you are a genius! We tried it out last night and one wrench is torquing too high and the other too low. I plan on doing a proper calibration tonight. I'll report back.

Cheers!

 

[Morris]

Adrian... I would encourage you to go ahead and heli-coil the block. Why? Because what you are about to do is exactly what I would do to save time and money and anytime I do something like this to save time and money it goes south.

If you skip the heli-coil, maybe the studs will hold, maybe they won't. Who knows when they will give out. You will always wonder. And if it doesn't hold, you will have fried yet another $15 head gasket.

Save yourself a tonne of heartache and do it the right way while you already have everything a part. I promise you you will be glad you did.

 

[bigjones]

Morris,
Thanks for the post.
Yes, you've convinced me. I thought if it sealed OK and ran well for a couple of days it would be fine. However, if there is a chance they could let go at any time in the future, well that changes things.

Especially in light of the following development:

This put an end to my torque wrench calibration Ha!!:

One torque wrench "calibrated" yesterday evening was tightening below the value indicated. The other wrench I was calibrating today before the vice lost interest. However, results so far indicate that it too was undertightening the nuts rather than overtightening:

It therefore seems the problems experienced so far were not caused by me inadvertently overtightening. This is good news for me as I was feeling bad but it is not good news with respect to the car getting fixed.

As far as hleicoils - I have an electric drill but the odds of me drilling exactly perpendicular to the block is zero. I'll be discussing this problem with a well respected LBC shop tomorrow to see what they think and if they can do the installation w/o removing the engine.

Will report back.

Cheers

 

[Guest]

Adrian... I would encourage you to go ahead and heli-coil the block. Why? Because what you are about to do is exactly what I would do to save time and money and anytime I do something like this to save time and money it goes south.

Save yourself a tonne of heartache and do it the right way while you already have everything a part. I promise you you will be glad you did.

Hahaha, my thoughts exactly!

Adrian, if you do it yourself, you can use the head as a guide if you get a bit long enough. OR, make a guide.



IIWM, I'd oull the motor, drop tha crank, tape up all hole and bring it in to a machine shop and have them do it. While you'r at it, might as well tear it down, boil it out, hone, polish , rings,rods mains and such is not a complete rebuild.

 

[bigjones]

Kellysguy,

I hear you - but pulling the motor is way beyond my skills, equipment, confidence level and life insurance.

Cheers!

 

[JPSmit]

Kellysguy,

I hear you - but pulling the motor is way beyond my skills, equipment, confidence level and life insurance.

Cheers!

It's a little beyond my driving range, but, I hope there are some BCFers close enough to mount an O.H.S.H.I.T. day. (guys?)

 

[Guest]

No it's not !!!!

Can you change a light bulb?????


Dude, pulling a head and putting it back together correctly is more difficult thatn pulling a motor.

Any monkey, gorrilla or other primate can pull a motor.

 

[dklawson]

I agree. Use the head as a drill guide. Even if you use nothing more than layers of masking tape to keep the drill bit centered in the holes through the head. That will keep things perpendicular AND on location. For the HeliCoil tap you may have to make a wooden jig to keep things square.

 

[JPSmit]

No it's not !!!!

Can you change a light bulb?????


Dude, pulling a head and putting it back together correctly is more difficult thatn pulling a motor.

Any monkey, gorrilla or other primate can pull a motor.

Be nice, it's intimidating the first time, ask me how I know. especially without someone close by to take you through the first time.