Sharing interesting head gasket failure
#11
@nathanb all of them - it is literally luck of the draw - theoretically the D2 after 2002 would be worse as they upped the engine temp so more thermal cycling. But overall block cracking is not that common, actually less common than BMW heads micro cracking. It generally takes consistent overheating events, and running hot. A common cause was ARP studs way over torqued, the original torque setting were wildly high, the setting now is 75 to 80 I believe, and originally it was well over 100.
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#13
#14
I wasn't meaning to imply that the thread should be deleted. It just seems like a regular head gasket break to me. Unless I'm missing something.
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cds72911 (11-10-2023)
#15
Every circumstance is different.
#17
I agree with Walt. Extinct is one of the most experienced and respected LR techs on the forum, so his opinion is always worth seriously considering. As an Aircraft Mechanic, we would never use a wire wheel on aluminum, as small bits of the steel will stay in the aluminum, setting up galvanic corrosion.
#19
Everything is off both heads. Might as well do both as do one.
I measured the blocks and heads with a machinist straight edge and they are shockingly flat. Not worth the cost/effort to resurface.
I ponied up and bought the genuine 3M roloc arbor and a handful of the blue very fine surface conditioning disks from my local auto parts supplier ($$$). 3M sure is proud of their stuff, and local prices are 2x online.
None of the machine shops I've contacted have retuned my calls. So, I picked up a cheap parts washer with parts wash fluid that is aluminum safe - I've wanted one for years and this is as good an excuse as any. I'll change the valve seals and lap the valves myself. I will chase the threads for the head bolts and the exhaust manifolds, as well as any others that look like they need it.
Parts are arriving. The new gasket kit (including Elring head gaskets), head bolts and some random bits (airbox hose, pcv hoses) are here, so I'll probably get into it this weekend. I'm still waiting on exhaust manifold bolts, but they're on the way. I'm also waiting on an Extinct coil pack relo kit that I should have bought a year ago - the last person to install the coils installed two mounting bolts, one only half way.
Everything looks good - but @miron mentioned other damage... Could you share what damage to the cams you saw? Anything I can measure to see if the cams are out of spec? What resistance spec should I see on the coils (I will look in the Rave too).
I measured the blocks and heads with a machinist straight edge and they are shockingly flat. Not worth the cost/effort to resurface.
I ponied up and bought the genuine 3M roloc arbor and a handful of the blue very fine surface conditioning disks from my local auto parts supplier ($$$). 3M sure is proud of their stuff, and local prices are 2x online.
None of the machine shops I've contacted have retuned my calls. So, I picked up a cheap parts washer with parts wash fluid that is aluminum safe - I've wanted one for years and this is as good an excuse as any. I'll change the valve seals and lap the valves myself. I will chase the threads for the head bolts and the exhaust manifolds, as well as any others that look like they need it.
Parts are arriving. The new gasket kit (including Elring head gaskets), head bolts and some random bits (airbox hose, pcv hoses) are here, so I'll probably get into it this weekend. I'm still waiting on exhaust manifold bolts, but they're on the way. I'm also waiting on an Extinct coil pack relo kit that I should have bought a year ago - the last person to install the coils installed two mounting bolts, one only half way.
Everything looks good - but @miron mentioned other damage... Could you share what damage to the cams you saw? Anything I can measure to see if the cams are out of spec? What resistance spec should I see on the coils (I will look in the Rave too).
Last edited by cds72911; 11-10-2023 at 12:39 PM.
#20
You guys may have noticed the new head gaskets have dimples in them. These are there to help hold the gasket in place between the flat surfaces. As you clean the surfaces do so parallel to the cylinder diameter. Whatever material you use will leave some sort of microscratch. Those mictroscratches can help to hold the gasket in place against the cylinder pressure. The reason the OP gasket failed originally was because the thermal expansion and the pressure of the cylinder pushes the surfaces between the head bolts apart and the cylinder pressure pushes the gasket out. Lower temperatures help reduce the thermal expansion and reduce the possibility of head gasket failure. The original SBC family use 5 head bolts per cylinder instead of the Rover 4 bolt configuration (common in other engines also including the new generation LS and foreigh manufacturers - Volvo, Porsche, etc). The issue for the Rover is related to the thickness of the deck surface on the cylinder heads, the LS uses a thicker deck so they don't need the five bolts and they lightened the block and heads in other areas. All we can do on the Rover V8 is lower the temp, carefully tighten the head bolts, and be careful during cleaning and assembly.
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cds72911 (11-10-2023)