Crankcase Pressure

[Alan Nyhus]

Originally Posted by HandOverFist

I'm no expert for sure, but I also don't have any Dart blocks lying about. It's my understanding that the Dart blocks oil differently and likely less oil up top to contend with. Using these old GM blocks my solution just seems to make sense to me.

Rich, here's a Dart SHP:



The valley is much like a big block Chevy. They are a priority main oiling system, so the mains get oil first, then the cam/lifters....just the opposite of a factory small block. You can flood the top end pretty easily, so the lifters need to be chosen carefully.

[HandOverFist]

Originally Posted by Alan Nyhus

Rich, here's a Dart SHP:



The valley is much like a big block Chevy. They are a priority main oiling system, so the mains get oil first, then the cam/lifters....just the opposite of a factory small block. You can flood the top end pretty easily, so the lifters need to be chosen carefully.

That's a nice looking piece there Alan...maybe some day before I die I will get to join the big boy ranks. With holes that large I would at a minimum have to screen them just for peace of mind.

[carl hinkson]

Originally Posted by HandOverFist

I'm no expert for sure, but I also don't have any Dart blocks lying about. It's my understanding that the Dart blocks oil differently and likely less oil up top to contend with. Using these old GM blocks my solution just seems to make sense to me.

Dart blocks do use priority oiling and they get the same oil up to the top as a stock block. Nothing is restricted on the block to decrease the flow of oil to the top end.

Don't use the Dart cam bearings with 3 holes to much bleed off if you want to talk about oil running down on the cam.

[joespanova]

Originally Posted by carl hinkson

Dart blocks do use priority oiling and they get the same oil up to the top as a stock block. Nothing is restricted on the block to decrease the flow of oil to the top end.

Don't use the Dart cam bearings with 3 holes to much bleed off if you want to talk about oil running down on the cam.

......and IIRC that's easy to see when priming on the stand with the intake off........I'll vouch for that.

[Bobby Fazio]

I was getting oil in the intake. I'm going to try an oil separator and reconnect the pcv valve to the factory spot in the back of the manifold. So let me see if I understand this. At idle the gases are being sucked into the valve cover breather through the crankcase, out the pcv valve and back into the manifold. At full throttle the pcv check valve is closed and the valve cover breather is handling all evacuation of the crankcase?