440 w/TorqStorm SC - Boost Getting Into Crankcase?? Valley Pan BULGE
My engine builder says he's stumped how boost ended up pressurizing the crankcase at our dyno session. This is a freshly built built 440 (1974 RB Block). The first run went fine, generating ~600 horsepower at 5200rpm. On the second run, the engine fell on it's face at around 4000rpm.
The dyno technician noticed that oil had sprayed out of the breather, and that the valley pan had bulged completely outward! I've never seen anything like this. There was no smoke in the exhaust. My builder tore down the engine and reported that the ring seal was excellent on every cylinder. The intake gaskets were fine. The head gaskets were perfect.
My only concern with this build is that he went with 10:1 pistons to begin with? I don't know if that could be a factor. I thought older engines needed lower compression for boost (9:1 or 8:1).
This is a mystery. Hopefully someone has some insight on how boost could enter the crankcase with good ring seal and good intake gaskets. Any ideas would be helpful. I can include some pics of the set-up.
My engine builder says he's stumped how boost ended up pressurizing the crankcase at our dyno session. This is a freshly built built 440 (1974 RB Block). The first run went fine, generating ~600 horsepower at 5200rpm. On the second run, the engine fell on it's face at around 4000rpm.
The dyno technician noticed that oil had sprayed out of the breather, and that the valley pan had bulged completely outward! I've never seen anything like this. There was no smoke in the exhaust. My builder tore down the engine and reported that the ring seal was excellent on every cylinder. The intake gaskets were fine. The head gaskets were perfect.
My only concern with this build is that he went with 10:1 pistons to begin with? I don't know if that could be a factor. I thought older engines needed lower compression for boost (9:1 or 8:1).
This is a mystery. Hopefully someone has some insight on how boost could enter the crankcase with good ring seal and good intake gaskets. Any ideas would be helpful. I can include some pics of the set-up.