My CNC'd head ports finished by hand!
06-17-2024, 10:34 PM
#21
Burning Brakes
One more comment and one more question: From the dyno graph it appears that the wheel torque is reduced below 4100 RPM, so the claim that power is increased everywhere is at odds with the dyno results.
From the beautiful photos that OP has provided, it appears that the lower end of the valve guides have been machined. I wonder if this is a great idea for our LS7 engines which are plagued with excessive valve guide wear as well as lateral forces on the top of the valves due to high rocker ratio and geometry. I can see contouring the exposed end of the valve guides to minimize flow reduction, but not cutting them off entirely. If anything, I would prefer longer valve guides if I cannot have roller-tipped rocker arms. Seeking comments from our cylinder head gurus.
From the beautiful photos that OP has provided, it appears that the lower end of the valve guides have been machined. I wonder if this is a great idea for our LS7 engines which are plagued with excessive valve guide wear as well as lateral forces on the top of the valves due to high rocker ratio and geometry. I can see contouring the exposed end of the valve guides to minimize flow reduction, but not cutting them off entirely. If anything, I would prefer longer valve guides if I cannot have roller-tipped rocker arms. Seeking comments from our cylinder head gurus.
06-22-2024, 03:10 PM
#22
Racer
Thread Starter
One more comment and one more question: From the dyno graph it appears that the wheel torque is reduced below 4100 RPM, so the claim that power is increased everywhere is at odds with the dyno results.
From the beautiful photos that OP has provided, it appears that the lower end of the valve guides have been machined. I wonder if this is a great idea for our LS7 engines which are plagued with excessive valve guide wear as well as lateral forces on the top of the valves due to high rocker ratio and geometry. I can see contouring the exposed end of the valve guides to minimize flow reduction, but not cutting them off entirely. If anything, I would prefer longer valve guides if I cannot have roller-tipped rocker arms. Seeking comments from our cylinder head gurus.
From the beautiful photos that OP has provided, it appears that the lower end of the valve guides have been machined. I wonder if this is a great idea for our LS7 engines which are plagued with excessive valve guide wear as well as lateral forces on the top of the valves due to high rocker ratio and geometry. I can see contouring the exposed end of the valve guides to minimize flow reduction, but not cutting them off entirely. If anything, I would prefer longer valve guides if I cannot have roller-tipped rocker arms. Seeking comments from our cylinder head gurus.
The torque loss is minimal below 4100rpm and honestly that amount of loss could be from Dyno pull to Dyno pull.
And I do have roller tip rockers. When I received my heads from Wilkes performance the valve guides were already cut for better air flow. I do understand that concern. And it's something that I'll check periodically.