Think the 450 needs a head gasket

I was crying on here a while back about getting my rigs to start up nice. Got the loader all worked out.
Next up was the 450 w/ cummins. Took a while to get 'er going but she fired up after some white smoke and I got her into the shop as fast as I could. There she sat until today. After dinner I got to poking around. I thought I will do a full service and than go over the electrical and double check all connections and see how it starts then. First I drain the motor oil, low and behold there is coolant in it. I flush it as best I could. Hop up top and sure 'nuff the coolant is low. About a litre short (that'd be a quarter gallon to my American friends here).

Last time it was hard starting and kicking white smoke I had a cracked head gasket. I got my mechanic friend in (he's got about 200 years of experience welding and H.E. repair) and we changed the head gasket. That was 'bout 5 years ago or so.

I would imagine a head gasket would last longer than that. So, at any rate I can't seem to get ahold of this mechanic any more so looks like I will be attempting to change this head gasket by myself. Be prepared for a sh!t ton of questions over the next couple of weeks!

Merry Christmas and happy new year to all!!

If its letting coolant into the oil through the head gasket it would be letting compression into the coolant when the engine is running and cause overheating,check the coolant in the rad for air bubbles this is best done when the engine is warm,take the fanbelt off the tensioner so it will hang loose and not drive the water pump,fill the rad to near the top,start the engine,run it at around 1000rpm and watch the coolant,you are looking for air bubbles coming to the top,if you got bubbles compression is leaking in,no bubbles the coolant is getting in from some where else,was the exhaust covered,that engine does not have sleeves but could have a pitted bore,it's best to see if it has bubbles first.
AJ

The machine is still hard starting. When I put the brand new battery to it with a battery charger set to "start" to boost it, it still turns over like it's got a half dead battery.

The starter was freshly rebuilt so I don't know if one has something to do with the other???

I will try get it to start tomorrow and see about the bubbles.

The exhaust isn't usually covered so this could be could be an issue well.

If the coolant you found in the oil had antifreeze in it then it wont be rain water,if the head gasket is leaking it could indeed be the cause of the slow cranking and bad starting,check for the bubbles and go from there.
AJ

The head gasket isn't that hard to do on the Cummins. Just don't forget that Cummins uses a torque/turn method of tightening the head bolts. As a result you'll need to measure them to insure they can be reused, and aren't stretched. Usually there will be a gage in with the head gasket kit, so that shouldn't be much of a problem. Beyond that, if you don't have a degree wheel to help get the right turn angle after the initial torque, it would pay to go ahead and get yourself one. It's not 100% mandatory that you use one, but it definitely helps when you can see exactly what your doing -vs- simply getting close using marks on the bolt head and block. Good luck.

NC,
Am a novice about much that is posted but still like to extend some mechanical understanding. Question is, what is a degree wheel? Know a little about torquing head bolts but was still curious.
Mr. T. Minnesota

Here is an explanation of the procedure and why.

There are three types of procedures used for torquing: torque to yield/angle to turn; torque to maximum stretch yield; and torque to a specific torque number and hope it's correct.

Basically what it comes down to, is that torquing with just torque values such as foot-pounds or newton-meters is at best a guess at getting the torque correct. Depending on the type of fastener, materials used for both the bolt and the part it screws in to, cleanliness of the thread, lubrication used, TYPE of lubrication used, etc., the torque between two "identical" fasteners can actually vary by as much as 35% (or more) with the torque wrench having the same setting for both fasteners!
Many fasteners, such as wheel studs, water pump bolts, etc., are just there to make sure that the bolt is probably tight enough, and probably not too tight. These are the bolts that you reuse over and over without any problems.

Head bolts, as well as most of the bolts internal to the engine, are what are called stretch bolts (also known as torque-to-yield bolts). These are designed to be tightened to the point they physically start to stretch, usually by a few thousandths of an inch. This leaves them in a elastic condition, that allows very equal clamping forces to be applied to the part they're holding down.

When you tighten one of these bolts, the torque setting that is used is designed to get the bolt close to the point that it starts to stretch. The torque angle guage is then used to put the bolt PAST the point it starts to stretch and actually start to stretch it. You just can't accurately measure this with a regular torque wrench, thus the torque-to-yield/angle-to-turn method. The Maximum stretch yield method doesn't apply here, since you need A) A very accurate micrometer to measure the actual bolt stretch, and B) Access to both sides of the bolt, which you don't have on head bolts.
The torquing process is quite simple. You simply torque the bolt using a normal torque wrench to a pre-determined torque. Then, usually you'll warm things up by running it at idle, then let it cool back down and re-torque again with the torque wrench. After that part is done, the torque angle guage comes into play. The torque that the bolts are at after the regular wrench is theoretically just before the bolt starts to stretch. This accuracy depends of course on the factors mentioned above. To get the final torque AND stretch on the bolt, you tighten the bolt a given number of degrees of rotation. This is what the torque angle guage is for, accurately measuring the degrees of additional rotation (typically accurate to a degree or so).

The Reason For Not Re-Using Stretch Bolts

The reason is quite simple. Once you have stretched the bolt once, it never returns to its original size. This weakens the bolt, and if you try to re-use it, you take a risk of snapping the bolt in two, leaving the threaded part in the block, the top in your hand, and a complicated repair required. It's just not worth the risk to try to re-use old bolts.

You can get replacement bolts that are not designed to stretch at the torque required to hold the parts together.

There are two good reasons for using non stretch bolts. You want to re-use them in the future, and/or you have an engine that is either forced induction (745i running massive boost for example) or very high compression. Since the bolt is already at it's maximum stretch without losing strength, you don't want to put undue stress on it from a high compression engine and take the risk of a blown head gasket.
There is also a good reason for NOT using these bolts, and staying with the original OEM style stretch bolts. Non stretch bolts require re torquing after a few heat/cool cycles (usually specified at around 5-6 cycles), and may have to re-torque them anywhere from every 30k to 70k miles, depending on application. If you have a normally aspirated engine, there's just no reason to have to do the extra work when normally you wouldn't touch the bolts again after they've been done properly with regular OEM stretch bolts. Also, stretch bolts tend to provide more consistent, even clamping pressure than the solid bolts do.

Well, hopefully now you have an understanding on what stretch bolts are, what a torque angle gauge is, and why you really do need one to properly tighten the OEM head bolts.

I said 'degree wheel', which is technically what it is, but in this instance I should have actually said a 'torque angle indicator'. Basically it's a tool that goes between the socket and the driver. The outer part of the tool, with the marked degrees, is held stationary while the inner part, with the pointer, is turned along with the fastener. This gives you a true reading of the degrees of turn you put on the bolt over and above the initial torque.

Basically this means instead using a true 'torque' reading, the extra turn stretches the bolt to apply the correct amount of holding power to the fastener. This is usually what they do when there are bolts of different lengths that all need to be holding with the same amount of force. They do this because a longer bolt will tend to twist more than a shorter bolt, thus giving a false torque reading when relying on a torque wrench alone. In other words two bolts of different lengths will tend to hold more, or less than another bolt of the same diameter when torqued to the same amount, which isn't good when your needing to keep a head unstressed, flat, and tight. This is important on a Cummins given that they have several different bolt lengths holding the head on. That's why they come with a gage to let you know whether the bolts have been stretched too far to maintain their holding power with another use.

Click on the link to see what I am talking about. I've got one of the ones with the 90 degree pieces to hold it, and a second one with the cable and clamp. Personally I like the one with the cable and clamp better than the other as it's much easier to find somewhere to clamp it too rather than trying to get the angled one to fit somewhere.
Poke here

NC,
Thanks for the thorough and understandable explanation. Like to learn something every day
Mr. T. Minnesota

I've build quite a few engines, of numerous brands, over the years, and have seen heads torqued in a number of different ways.

Usually on the engines ones, for instance the one in a D9G like I'm working on now, where the bolts are too big for the normal man to really twist off anyways, they are usually just torqued to a specific torque (typically in several steps) and done. In this case I think they are torqued to something like 350 ftlbs. but they are actually 7/8 fine thread studs, so I'd play heck ever going too far with them.

On the other hand, engines like the Cummins B series are using something like a 13mm sized bolt, are torqued in several steps to a final torque, and then have a final torque turn applied to them from there. As small of a diameter as they are, the stretch put on them by tightening them this way is tremendous, to say the least. But, as you said, the stretch keeps them tight, as opposed to the larger bolts/studs that simply need to be TIGHT to stay that way.

Now I'll throw a good one at you. I did a small Deere engine awhile back. Thankfully all I had to do was pull the head, but unlike the Cummins, that allows you to reuse the bolts if they are within the gage spec, Deere says replace all of them every time the head comes off. The bad thing there is a set of head bolts, and they are special, were something like $200. Now the fun part. With this engine you tightened all the bolts, in steps, to a specified torque. Once you go them all tight, you then started back at the first one and loosened it all the way. Then you re-torqued it to yet another spec. Once to that spec you put the indicator on it and further tightened to a degree that varied in relation to the length of the bolt.

I've seen the torque turn method used many times after reaching the initial torque spec, but this is the first time I've ever seen it where you loosened the bolt, and torqued it to a completely different spec before doing the torque turn.

I learned something today!! That was a lot of good information. Thank you for much taking the time to share.

We used the method you described to tighten/re-tighten/stretch the head bolts on our supercharged offshore race motors. Helped the head gaskets from getting spit out. That was before the many of the aftermarket blocks came on the scene that had the extra blot holes and better head gaskets, namely Cometic Phuzion.

http://www.cometic.com/files/cometicphuzion.pdf

The reasoning we were given for the tighten-torque / relax / re-tighten-torque individually was the reduction friction both under the head and the threads during the initial pull to torque. We didn't seem to have the same issues when we used ARP studs and there thread lubricant.

We tightened our rod bolts via the stretch method not torque. Generally they were replaced on every 2nd rebuild cycle.

Just more information.......