Head Gasket for sho!!

 

<div class="FTQUOTE"><begin quote>Originally posted by: 650VIPER

Head Gasket for sho!!</end quote></div>

[img]i/expressions/face-icon-small-frown.gif[/img]

What He ^^^ Said.

Sorry man.

 

OK so several of you have confirmed what I was thinking. I guess the head will be coming off again[img]i/expressions/face-icon-small-sad.gif[/img] I didn't realize by the number of responses that so many have had head gasket issues on DS's. I know some big bores have head gasket problems but I did not think it was very common on stock bores like mine. When you start getting into higher compression (i'm at 13:1) does it just become the nature of the beast? What do I need to do to lessen the chance of this happening again? I did not get a lot of ride time out of this particular head gasket (maybe 20hrs)[img]i/expressions/face-icon-small-sad.gif[/img] If this is the kind of head gasket reliability I can expect at 13:1 I might just go back to the old reliable 11.5:1 gasket I was running without any problems. I sure would miss the extra snap with the higher compression.

 

When you rebuilt the motor, did you replace the nuts for the headbolts?
After 10 hours of run time, did you retorque the head?

With higher compression, new head gasket and probably new base qasket,
retorqueing is a good idea.

OMR

 

No I did not replace the nuts for the headbolts. What is the reasoning in replacing them?

 

metel stress ,and stretch

 

When you tighten a bolt, you flex it and make it slightly longer. The bolt resists this flexing and becomes a spring. If you severely over-tighten the bolt, you could bend them. A bolt that's been bent (permanently stretched) by over-tightening doesn't apply the correct amount of clamping pressure and is likely to eventually fail, either by loosening or breaking.

Lubrication is to ensure that the applied torque deforms the bolt along its axis (stretch) instead of around its diameter (twist). If you've ever had a bolt back off a little when you released the torquing force of a wrench, then there was too much friction between the threads, and the bolt did not receive the intended amount of stretch (spring tension). Lubrication of the bolt threads is important only to ensure that this doesn't occur.

The common standard for thread lubrication is a light coat of oil of about 10W viscosity. A thin coat of most engine oils does just fine. The idea is to allow the threads to move against one another and light oil does that reliably.

The nuts that connect to the headbolts are specially designed to overstrech or break before the headbolts fail. Great design. The only issue is that they can only be used one more time safely. Sometimes twice if for a stock machine.
For high compression motors I would recommend changing each time the head is off.

OMR

 

Are the head bolts/nuts special grade? WHere should I look to replace? I'm going to be contacting Eric (HPR) for the new head gasket, should he also have replacement bolts/nuts?

thanks

 

Eric will have everything you need.
I never replaced the nuts on any of my builds. But I am careful to add oil to the threads before I put the nut on, and careful with torqueing them down.
I have never had a head gasket failure, but I have fixed some that have. Most of the time, I have seen the bolt on the chain side loose, not the stays. And even with a good cometic, they will still leak.
Sorry to hear this. I dont think once you got it done right, you will have an issue. When you start to take it apart, retorque the bolts before you loosen them, just to see if they are loose. That will tell you if thats the issue.....

 

Crap I think thats my problem too.

So would a blown head gasket change your oil to look milky or is that the water pump impeller seals?

I keep losing coolant like crazy with no leaks I can see and my oil has white foamy stuff on the dipstick.