Some of you guys know that I'm a proponent of the "big head/small engine" argument, and this month there was an actually good article in MM&FF about just that.
I know magazine articles have to be taken with a grain of salt, but I thought this one was noteworthy, and I figured a few of you guys would get a kick out of it.
If you haven't already flipped through it, MM&FF ran four different cylinder heads on two engines, a 302/306 and a 302/363. The cylinder heads were all Dart Pro 1 units, in flavors of 170 and 195 (as-cast) and 210 and 225 (CNC). According to the article, the 225s peak flow at 325CFM.
All variables were held constant across the tests for either engine, like compression, cam, intake, etc.
Long story short, they managed to blow the 302 up before they could test the 170s (WTF!?), but they did test all the others. Oddly enough, they cut the 302 off at 6200 RPM for the tests (again, WTF!?) which is frustrating, but I think the test data is clear enough for what it is.
Bottom line, the three heads tested on the 302 made damn near identical power numbers from the start of the test (2800 RPM) up to 6000 RPM, where the 195s seemed to run out of air. Both the 210s and the 225s continued to post growing numbers up to the test cutoff at 6200. Both were 399 HP at 6200 RPM, and I'm sure they would have made well over 400 if they would have spun the engine further, but that's not the point. The point is that the low RPM power/torque numbers were unhurt by the "huge" heads.
They revved the 363 up to 7K, and it did exactly what you'd think it might. Same story, really. The bigger the head, the more power it made.
Thoughts?
I know magazine articles have to be taken with a grain of salt, but I thought this one was noteworthy, and I figured a few of you guys would get a kick out of it.
If you haven't already flipped through it, MM&FF ran four different cylinder heads on two engines, a 302/306 and a 302/363. The cylinder heads were all Dart Pro 1 units, in flavors of 170 and 195 (as-cast) and 210 and 225 (CNC). According to the article, the 225s peak flow at 325CFM.
All variables were held constant across the tests for either engine, like compression, cam, intake, etc.
Long story short, they managed to blow the 302 up before they could test the 170s (WTF!?), but they did test all the others. Oddly enough, they cut the 302 off at 6200 RPM for the tests (again, WTF!?) which is frustrating, but I think the test data is clear enough for what it is.
Bottom line, the three heads tested on the 302 made damn near identical power numbers from the start of the test (2800 RPM) up to 6000 RPM, where the 195s seemed to run out of air. Both the 210s and the 225s continued to post growing numbers up to the test cutoff at 6200. Both were 399 HP at 6200 RPM, and I'm sure they would have made well over 400 if they would have spun the engine further, but that's not the point. The point is that the low RPM power/torque numbers were unhurt by the "huge" heads.
They revved the 363 up to 7K, and it did exactly what you'd think it might. Same story, really. The bigger the head, the more power it made.
Thoughts?