The Belt Drive has shown to work flawlessly!! I want to make a couple small changes to be a little more user friendly.

Great that you're making stuff for the GIII.

I have one nagging question, though...Isn't the best valve action obtained from having the rocker/pushrod angle to be 90 degrees at full lift? IIRC that gets the valve off the seat faster, so the valve is open longer. Or is this an area where best practice has changed? I mean, you are in the heart of NASCAR country and they do obscene testing.....

R.

I would have liked to see a 1.7-1.75 ratio rocker. Still nice work as always Steff

I may be able to do a 1.7 ratio for the prototypes on my heads. Need to check spring installed heights.

Oh man when?! Was on a search for Arrington rollers but another option would be great. Will they clear the big retainer from the dual valve springs? The T&D was an option till I found out the wouldn't clear. Would be nice to be able to do .700 lift at the valve without spending $10k on a Jesel.

So when you putting all this cool eye candy into production and selling it to us?

Any updates on the rockers

90 degrees at full lift is slower from closed, and has smaller area under the curve.

Just a guess: the 12 degree correction isn't because the OEM parts are bad - the 90 degree/50% lift is the best plane geometric model, but not necessarily the best rocker arm. Pallet rocker don't use it to get some anti-scrub effect.

90 degrees at zero lift gives you fastest off the seat valve action and least lift at max lift.

90 degrees at open gives you most total lift and softest touchdown on the seat but it is hard to keep the valve from losing contact with the rocker tip.

90 degrees at mid lift (or somewhere close depending on who you talk to) gives you the best of everything.

Anywhere except 90 degrees rocker/valve relation will give less than max ratio. Don't forget that if you have a roler tip than the (theoretical) tip of the valve is actually going to be the center of the roller.

My point: the largest possible area (average lift X degrees open) as a math model isn't always what the engine wants, or what provides the best service life for the parts.
500 years ago, Warren Johnson (yes, the same guy) adjusted the rockers on his Olds for higher lift early in the event to get closer to the piston's maximum velocity = highest vacuum.
Note: no, the ICL can't be at the stroke's midpoint without very bad results.
Vizard has been doing some interesting work comparing BBC rockers that (are designed to and/or adjusted to) produce high lift very quickly.

Prototypes are being machined.

What's the max lift you are looking to handle
Assuming steel as the material but if they work out will you consider aluminum for lighter duty engines
How do you test them assuming on an engine of course but are there other test or is there such a thing as a dyno for rocker gear
Thanks for the info steve

I ended up with a 1.72 ratio on the intake rockers and 1.68 on the exhaust. I have a .410" lobe. With lash, looking at about .691" lift on the intake and about .670" on exhaust. Material is steel. No plans to experiment with aluminum. I designed them to clear a 1.300" dia. LS dbl. valve spring. Testing is putting them on my own motor and let er' rip!! What ever happens, happens....good or bad. It's the only way you learn things.

Steff that is just awesome.

so are you thinking the springs were your problems? You really cant run a dual valve spring on the newer heads because of the boss is holding the guide on top instead of in the port like the 6.1 heads. But you can fit much bigger behives on the newer heads

It sounds like STEFF is using the companion software to Solid Works called Simulation I am assuming. I have used Simulation for many engineering projects in the past. It is a very powerful and accurate program, that is about the best testing you will get from a design side of things. If I was a betting man, I would say if STEFF has all the bases covered, which it looks like that is the case, there will be no surprises with the prototypes when they are tested in real life application.

-Kenny

Good work there. Do you happen to know the offset of the intake rockers and the angle between the intake valve and pushrod?






While I don't agree that testing is the only way to learn things it is a necessary part of the design process, and fun too!

KOOL...

His process is already commercially available here.

http://formlabs.com/

What he has done is a better job of refining the laser/resin printing. Luckily that technology has lost its patent (expired do to age of patent) this past February so it has become open technology.

A lot of exciting things can happen with 3d printing technology that most people don't think about. I don't have time to go into all the details but it has the potential to do more than just make prototype parts. I teach this stuff and your talking Environmental impact, lifestyle changes, innovative design princples. Imagine a world where you create mechanical designs or art that can be sold or shared like music on an Ipod.

I will tell you what will determine the presiding 3D manufacturing technology and it won't be what is best. In a few years Amazon/Walmart/Target/ etc will find a technology that will allow them to lease you a 3D printer the likes of which you could never afford. They will do it for cheap/free so they can sell you stuff online and no shipping cost for them except the supplies they may have to send you once a month. Once they latch on to something, better technology will be ignored in the face of profit margins. Think about Betamax vs VHS, the better lost and the higher profit margin product won.

I am glad to see that my rocker shaft collar design is still in use.