Thread: New Head Gaskets

Originally Posted by ozscott

So apart from the coolant leaking down front and rear of motor on the passenger bank it looks like there was blowby in number 5 too...so failure there? This was the composite gasket fitted less than 20 000k ago with stretch bolts.

Attachment 118268

Cleaned up pretty well Attachment 118269

I think you would find it is not the composite gaskets fault, gaskets are just the meat in the sandwich, they rely on whats above and below them have to be true to seal. Warpage of what is above and below them will cause a failure. So if the head warps they will allow liquid or exhaust gas to pass, and this will damage the gasket
People tend to incorrectly blame the Gasket component as the failure point when other contributing factors are the cause.

Originally Posted by ozscott

Also what do you guys reckon about a very thin smear of GM Head Stud Sealer on the coarse end only

The manfacturer of the head studs has clear instructions on what to do, if you now bring another thing into the equation, you may void your warranty.

Mario I know what you mean. I will see how the heads shaped up. The thinnest feeler Guage I have is 0.005. It is trapped by a straight edge every which way on the block...so block good as I would expect from an engine never overheated and which is very low kilometers.

ARP are a bit ambiguous about the coarse threads but say you can use Loctite thread sealer for water jacketed bolts....so that means you can use it on all bolts onto the block...and by definition and because they are only finger tight you could use any reputable brand of thread seal...so I have answered my own question I suppose.

Cheers

Same kit as you and like you I was uneasy with the 100 pounds as was everyone I spoke too hence I emailed ARP and they did not respond.

ARP dont specify the type of gasket but as their studs are a replacement for the standard one use stretch bolts it is logical the studs are for use with a standard head gasket - hence composite and if used on something else your sort of on your own.

My thoughts are that 100 pounds will work on a nice new clean block with nothing down the holes and the threads nice and clean with studs wound in to a little more than finger tight. When the nuts are tightened up with the heads on - 4 stage tightening technique with the correct lubricant on the thread but on all the surfaces such as washers and the base of the bolt where they move over the washers.

It is really worrying when you have makers instructions but the entire brains trust says no and the maker will not respond to questions.

80 pounds should be good but dont blame me if ..... (it will be OK)

All LRV8 heat bolt holes are blind holes so won't need any thread sealant. If there's any sign of corrosion from water ingress it's either from a head gasket failure or a cracked block. I use nowt but a lick of oil so they are easy to undo at any time in the future. The last set of studs I took up to 80 ft lbs as previously at 90 they felt funny.

Originally Posted by ozscott

.....arrrghhhh!

been there--

Here is a photo of a clear leak from front exhaust gasket passenher side...don't think I posted this up before.

I am happy with the deck finish and this engine has done 42000 (looked at my records...was 22k when I got it...) BUT the more I read about MLS the more I reckon that unless the block is out and can be dressed I am better getting composite and using ARP. I think that will help preserve the block around the thread holes versus stretch bolts. I will go to 80 lb pounds in 3 equal segments and leave it at that with no retorquing. Cheers

I see green coolant stains is it OAT as more common OAT is usually pink. Are you going to use the recommended Oat in the rebuild

green is ok in v8's, no dis-similar metals, all oat does is (leak!) give you a longer use-by date,,