Any idea why the gasket blew?

 

Dang, hang in there bro, hope the studs are intact.

 

studs were intact. the 2 inside (under the rocker box) head bolts had loosened (not surprised given how much the gasket had blown out)

What scares me now is theres a bit of flame cutting on the head surface. enough to see, not enough to catch a fingernail on. ive cleaned it up, and while it looks pretty rough, the "scratches" are barely perceptible to a fingers touch

the culprit



the jug



the head

 

Stay strong brother!

 

one upside, the cylinder walls looked effing PERFECT....so overall break-in was a success


I just excel at breaking break-in's

 

I'll tell you my secret to making sure this doesn't happen again.... And this is the way I do it ..... Use a small amount of copper cote on the head gasket, do not use any lubricant on the head bolts or base of head bolts. Then follow the torque sequence in 10 lbs increments finishing at 55 ft/lbs, I know I know, per harley. I'm over torquing, yada yada yada, I've used the recommended 42 ft/lbs and had the bolts back out. Just like this .

 

bolts didnt back out


i pulled a ****ing stud

figured "ya know i probably oughta make sure these are okay" as i was torqueing the head. was up to 22lb/ft (3rd "step" per cometic), and the second bolt just spun.

got a call out, heres hoping my buddy has a couple of TimeCert's left over from his fathers bike (also pulled a stud)

 

Were the shoulders down on your bike ?

 

yes they are shouldered studs, and yes they were bottomed out tight against the cases.

 

correction....i pulled (2) studs

now the cause: they torqued down properly (in sequence to 42lb/ft) on reassembly. perhaps they were right on the ragged edge, and the W6H with its .590 lift and compression-building characteristics just said "oh eff you"...i honestly couldnt begin to guess. 190psi cranking compression....shes up there, but should be far from ripping studs