Seem to have blown a head gasket

[Huff N Puff]

Blowing oil out of the front of the head gasket,seems to be related to oil pressure,cause it seeps out as I race the engine at idle. Doesn't seem to affect any other aspect of the engine e. g compression,coolant. Does any one know if an oil passage near the front of the engine runs thru the head gasket. I am also looking for Recommendations on the best head gasket set up to use that will hold up to a pretty heavily bombed engine running about 50 to 60psi of boost. Merv

 

[Rob Thomas]

Merv,



I had the same thing happen last year, driving casually to the coffee shop, and POW, oil everywhere, exactly where yours is leaking.



I didn't have time to o-ring, or find another, "better" gasket, so I got one from Cummins, run of the mill. I called around to see if this a common issue, and it seemed to be, seveal vendors told me the same thing, the fix is to torque the head to 130 ft. lbs.



That was 45,000 miles ago, I see 60psi regularly, and so far so good.



Later, Rob

 

[Rob Thomas]

Here's a pic of the toasted one.....

 

[jwilliams3]

The best bet is getting your head O ringed.

Then using a stock head gasket, from what I can tell people are having great luck for street use with a stock gasket and O rings.



But, I would not over-torque your head bolts.

This practice only stands to stretch the head bolts beyond their yield and possibly break off in the block.

If you want more torque, use studs.



--Justin

 

[Joseph Donnelly]

On the pushrod side, each sylinder has an oil feed hole from the main galley to the deck. The oil travels along a slot in the gasket and then goes up the head bolt hole to the rockers.

 

[Huff N Puff]

Has anyone used studs and a stock headgasket with good results

Thank you all, for your posts on this issue,I think I blew it while I was playing with boost pressures,I peged a 60psi guage a few times,I finally settled on about 50psi for boost,at anything higher, I felt a ratteling reverberation that didnt feel healthy,felt like detonation on a gasser ,power didnt seem any better either. Merv

 

[83 crew cab]

But, I would not over-torque your head bolts.

just as a side note if you use a dial torque wrench to watch the last step in the torque prosses (the lst 90 dergee) the will all come out to betwen 115-and 135 so if you go to an known value then you get a more even torque pattern

 

[Huff N Puff]

Tring to understand what 83 crew cab said

The final 90deg final is the equivilent of a total torque of 115-135ftlbs. please clear this up for me. Merv

 

[jwilliams3]

I believe (could be wrong here) but since these bolts have a tendency to stretch, some more than others.

Cummins gives the final stage in the torque sequence a 90* angle. This ensures an even amount of thread engagement with the block.

If you just take all the bolts to a certain torque spec #, you will find that some bolts will keep stretching, way beyond their yield.



At Cummins Midrange engine plant where these engines are manufactured, these heads are torqued by a machine with 26 electronic torque guns, simultaneously.

An almost identical torque sequence is used as stated in the Cummins technical manual.

The 90* angle is the final stage of this process and then the final torque angle and torque # is recorded.



--Justin

 

[83 crew cab]

huff n puff after being told to torque the head to 130 by very reputable companys. we thought that we would check and see what the 90 degree ='s. On the 2 eng's we checked they all came out betwen 115-130 I go to 125 now. I all ways watch the finnal torque and it all ways hit 125 between 90 degrees and around 150 degrees. the only head gasket we have had leak sence then is one that I did not get the dowl pin centered up on (both eng's are o-ringed and hit 60+psi of boost ) thats just we he have been doing not saying it is right but it seems to work George

 

[Rob Thomas]

Justin,



The head bolts are, "stretch" bolts, are they not? I see your point, but I have done this "re-torque" to plenty of trucks without any problems, and... .

Originally posted by Rob Thomas

That was 45,000 miles ago, I see 60psi regularly, and so far so good.

So if it works, and holds, whats the problem?



Later, Rob

 

[jwilliams3]

Rob,

I believe I went over possible problems in one of my previous posts.

The bolts can only stretch so much.

If your willing to risk a broken bolt, by all means go for it.



Clamping force is not increased significantly once these bolts are stretched too far (beyond their yield), you just get a weaker bolt.



Just my opinions backed up by some facts.

By the way... ... .

I haven't worked on any engines before. But, I did stay at a Holiday Inn express last night.



:-laf :-laf :-laf



--Justin

 

[Rob Thomas]

Originally posted by jwilliams3

By the way... ... .

I haven't worked on any engines before. But, I did stay at a Holiday Inn express last night.



:-laf :-laf :-laf



--Justin

Oh, well thats good to know. LOL

 

[Huff N Puff]

Question about studs

After installing studs is it easy to lower the head onto the block under the wiper cowling. Or do you lower the head first then install the studs. Merv

 

[ob1kobi]

Merv,



Sorry to hear about your luck. If you already have to tear the top of the motor off, you might as well get it o-ringed at the same time. Give Andy at Advanced Diesel Technologies a call, they are only a few hours away from you, and they can get it done pretty quick too.



Ted

 

[Rob Thomas]

Re: Question about studs

Originally posted by Huff N Puff

After installing studs is it easy to lower the head onto the block under the wiper cowling. Or do you lower the head first then install the studs. Merv

The way I gather, you must double nut the studs to install, AFTER the head is in place.



I hope I have enough room under the cowl, (now that I have this sweet body-lift), to mount the studs first.



Good luck, Rob

 

[LSMITH]

Mount the studs eh? Sicko... ...

 

[fest3er]

Originally posted by jwilliams3
... Clamping force is not increased significantly once these bolts are stretched too far (beyond their yield), you just get a weaker bolt. ...

Once it's gone plastic, it takes very little force to further deform it.

To use more ... technical terms, all bolts have an elastic range and a plastic range. As long as the bolt stays within its elastic deformation range, it will hold, though it could stretch a bit more from time to time. But the moment it changes into plastic deformation, it has stretched 'too far' and is worthless.

I can't think of a single everyday analog of elastic vs. plastic deformation, but here are examples of each. Take a rubber band. Stretch it and release it. It returns to its original size. That is elastic deformation.

Now take a plastic swizzle straw. Seems rather sturdy, eh? Grab one end between your molars. Get a good grip on the other end and pull, and keep pulling until the straw stretches. Now release. The straw retains its new shape. This is plastic deformation, the sort of thing you don't want happening to your head bolts.

Steel may be strong, but given enough force, it'll stretch like putty.

Fest3er