DAvid Vizard

Anyone read his article in Popular Hot Rod on cam springs and rockers? He actually said self aligning rockers were more stable on a spintron? anyone agree,disagree?

Anyone read his article in Popular Hot Rod on cam springs and rockers? He actually said self aligning rockers were more stable on a spintron? anyone agree,disagree?

No, I didn't see that yet. Thanks for pointing it out - I am looking forward to reading it. But if he said it, I'd be reluctant to disagree with him. He has a very clear writing style and his MO is to base his conclusions on his own testing, rather than regurgitating stuff. This clear style and factual basis make him the best technical auto writer out there, IMHO. One thing I have noticed about his writing style though is that he never means more (or less) than he says. IOW, if for example his statement was just about what he saw on the Spintron and did not express the idea that SA rockers were superior in a running motor I would not assume he meant anything other than what he said. You need to read anything technical carefully in order to understand it, even Vizards excellent prose.

Rich

Anyone read his article in Popular Hot Rod on cam springs and rockers? He actually said self aligning rockers were more stable on a spintron? anyone agree,disagree?

Vizard said: "Another move you might consider is the fact that self-aligning rockers that locate on the valve instead of being located by the pushrod guide plate have far better longitudinal stability."

My view is that your goal is to keep the roller on the rocker aligned with the valve stem tip. With SA rockers you are doing it at the point where it counts. With pushrod guide plates you are tryng to do it at arms length, and any motion of the rocker on it's pivot during its travel and any misalignment or angularity of the pushrod, and any flexing of the pushrod is magnified by the rocker ratio. That is probably what they saw on the Spintron. It sounds very logical to me.

Vizard is talking about longitudinal stability here, or perpendicular to the valve/pushrod, not stability in the direction of valve motion. That's the spring's job. He also goes into depth on valve bounce and rpm limits with hydraulics. It's a good read, and at 10 pages, long for a car rag. Fortunately those of us with short attention spans can take it one topic at a time.

I agree with what Rich said about DV. He speaks from experience and doesn't make wild projections. He'd probably be a lousy stock broker. :) He is also a good public speaker. His Brit wit shows thru.

My $.02

Yeah it was also good info on the Beehive springs.