the engine diagnosis game!
Crankcase pressure goes thru the roof so oil will get pushed out.
On the gasket.. the only reason it would pop there is either it pinged/detonated when you got on it, or the head or block isnt flat enough, or it wasnt torqed properly. If you look, number 7 also looks close to breaking and was pushing gasses into the crankcase too. Looking at it, I'd say it's not flat. I would use a machinist's straight edge to carefully inspect them both before you reassemble it. So did it ever ping? Carefully clean the carbon off the pistons... are there any tiny pits visible in the surface? Use a strong light and magnifying glass... look a tthe ceramic on the spark plugs.. any flecks of metal or tiny blueish/black spheres stuck to it? Most blown head gaskets are symptoms... not causes.
I just checked the deck on the head and block. The smallest feeler gauge I have is 0.002, and I could not get it under the straight edge anywhere.
As far as torquing, I followed the procedure in my rebuild manual. However, I do not know how many times the bolts have been used, and plan on purchasing new for reassembly.
The compression is running around 9:1, and I have been using 89 octane. I have not heard it pinging. This is my first engine project, I'm sure it was not tuned as well as someone with experience could, but I felt that the timing was good. I do not remember what the timing was set at, But I marked the distributor with a marker before I removed it.
I think it was running rich as well. I had not rejetted yet, but felt like I needed too.
The plugs have white on the ground strap, and the internet tells me that I am running a plug with too high of a heat range (Autolite 3923). However, this is how the plugs look after driving it easily for 50 plus miles with the blown head gasket, so it probably isn't an accurate reading. There is no aluminum on the plugs.
As far as cleaning the carbon off the pistons, what is the best way to do it? Is there a solvent to use, or a brillo pad? I'm assuming no sandpaper.
The gasket that I used is a mopar performance gasket, it crushes down to .024-.028 to help with the compression. they advertise that they are good to 12.5:1 . I was thinking about using these again since I have a pair.
I also plan on taking off the other head to inspect, change the gasket and install new head bolts.
Thanks for the help!
Steve