Inlet Port geometry - ZR-1 Net Registry Forums

tpepmeie · 01-25-2015

Just a couple more fun facts about these heads.

The Aurora inlet ports are inclined from vertical by 45 degrees, and the valve is inclined by 10 degrees. Therefore 35 degrees is the net port to valve angle. Pretty tall, straight.

The LT5, on the other hand, is approximately 58 degrees from vertical. The inlet valve is also 10 degrees. ~48 degrees port to valve angle.

The air has to turn through ~13 degrees more as it approaches the cylinder. For this reason, we have to do things like flatten out the floor of the short turn to get the air to turn better. Tradeoff is that the area gets bigger than we'd like.

Contrast that with the Aurora port which is absolutely constant area throughout. This is a totally round port all the way. It bulges just slightly at the valve guide area to keep the area constant.

01-25-2015	#1
tpepmeie Join Date: Aug 2005 Location: Fishers, IN Posts: 812	Re: Inlet Port geometry Just a couple more fun facts about these heads. The Aurora inlet ports are inclined from vertical by 45 degrees, and the valve is inclined by 10 degrees. Therefore 35 degrees is the net port to valve angle. Pretty tall, straight. The LT5, on the other hand, is approximately 58 degrees from vertical. The inlet valve is also 10 degrees. ~48 degrees port to valve angle. The air has to turn through ~13 degrees more as it approaches the cylinder. For this reason, we have to do things like flatten out the floor of the short turn to get the air to turn better. Tradeoff is that the area gets bigger than we'd like. Contrast that with the Aurora port which is absolutely constant area throughout. This is a totally round port all the way. It bulges just slightly at the valve guide area to keep the area constant.