There should be a setup tool included with the shaft-mount system. Basically you shim the base to where it needs to be for the pivot point to be correct according to the setup tool, then put the adjustable pushrod in to find the correct length while on the base circle of the cam.

 

I purchased a set of New Jesel Sportsman Series off Ebay for just under 600, a good deal, but keep an eye out and you may get lucky like me. I'm using them on LT4 heads, you should be able to use any tall center bolt valve cover, atleast it looks like I can with my setup. After installing the Jesel setup, I had to go to a shorter pushrod. Hydraulic cam. HTH

 

Thanks, this is what I needed to know. I am going to try and sell my stuff first. If I do I will look into the Jesel Sportsman series. They look like they are up to the task at hand for a reasonable price. I hope to get lucky here an make this work. I will then order pushrods once I have the shaft set up.

If I cant unload my set up now then I will order the 8.000" pushrods and get it running. Thanks for all your input guys!!!

 

Wonderful… now you guys have me wondering about something that I felt good, well at least OK about (always felt fine with what I ended up with and now I'm wondering about the engine that I'm putting toghther this weekend...).

Bret, what is “your way?” just shooting for the most centered pattern? I would agree with shortest pushrod = good thing, but…

It seems that almost universally everyone’s way besides comp cams says that the comp cams way is the wrong way to do it (don’t actually know what that is… I guess I’ll go grab my comp catalog and do some reading), and I finally settled for the “keep the shortest pattern you can get even if it does move it off center some (judging from your pics I’d probably pick the 8.050” pic), which usually comes closest to the miller mid lift geomemetry without too much futzing around, at least as close as you’ll come with whatever particular setup (seems like not many can get that dead on).

Has anyone actually compared different procedures on a dyno or spintron? Seems like miller claims that his way is actually worth significant HP.

What procedure do you guys like and more importantly, why?

 

You know, quite a few years ago I really got serious about rocker geometry and started taking some pretty accurate measurements... about on par with what you have done, but in a different way. Long story but here's the deal.... I quickly found out that the "Mid-lift principle" just didn't work. Ended up with sticks that were silly long. Then I started looking at factory-stock rocker geometry and suddenly I found sanity. Sanity is exactly what you're finding. Most of the movement happens in the first 1/3 of the lift and then it stays pretty motionless from there. Time and again factory stock setups showed that tendency, so I started thinking about it (always a dangerous thing when I start thinking).

Why have most of the movement in the lower lift range? Only one reason I could come up with: valve spring pressure. It's very modest at low lifts. If you're going to have two things shoving past eachother it's best to do it when spring pressures are lowest (least friction). When spring pressures are high you want as little movement of the rocker across the valve tip as possible.

If you look closely at the actual movement of your very long sticks you'll probably find the rocker tip is retracing back across the valve tip in the high lifts. At least, that's what I've always found. You will NOT see this just looking at witness marks on the valve tip. You must get out your reading glasses (if you're of the age you need such visual assistance) and actually watch it in action over and over again. Do it fast, do it slow, but do it about 20-30 times and you'll start to get an eye for it.

A small amount of retracing in the high lifts is fine, but if you get to the point you're doing a true mid-lift inflection point and coming all the way back to start you've gone so far as to be rediculous. The poly-locks probably won't catch more than a single thread on the rocker studs! Note that the "mid-lift principle" will ALWAYS give you the smallest contact pattern since half of the lift is just retracing back across the valve tip. This does not mean this is optimum rocker geometry- at least not how the factory defines it. There's probably good reason that a well centered contact area roughly equates to proper rocker geometry/pushrod length.

If I had to take an "internet guess" based just on your pictures I'd say that the 8.00" sticks are as long as you ever need them to be. Call me nuts, but I really don't have a major problem with the 7.95" sticks' pattern either- VERY "stock" looking.

 

I was almost ready to buy the 8.000's. But I have decided that the Stud mounts are or were not the best choice here. I am taking the advice of a few other in this post and going with a shaft mount set up. I sold my Melrose T-top cover, girdle, and promags to a local friend.

I will be ordering Jesel SS series shaft mounts in the very near future. I will have to remeasure again once I have them shimmed to the right height. This thread is still good info for anyone in the future. you guys have helped a ton.

Right now I am dealing with another issue all together. My LT4 intake doesnt seem to fit. I think it needs to be milled to fit on my heads and block. .010" ere and .010" there and next thing you know your $600 manifold doesn' fit

 

The Jesel's are a good choice. They have a rocker piviot farther away from the valve which will give you less friction and a better pattern.

Bret

 

Now see, that’s what I was getting at… If you throw in “if it’s an SR running enough lift/pressure to justify shaft rockers you should probably run .050-.100” longer than the pushrod that gets you the correct pattern to account for flexing…” and we pretty much have the entire range covered… so what’s actually correct?