Engnbldr, ever heard of roller rockers for the 22re? and if so would it allow you to increase the "ramp" of the cam profile for a benefit to performance?

Jay

>>>*Hi!
Well, the idea of roller followers makes me think. It sure could be done, and it changes all the rules. Less duration, less overlap, faster ramp, more power and quieter operation...*HMMMM.....
The stock style rocker arm has the cam lobe walk almost all the way across the pad at maximum lift.
This creates a situation where the rocker ratio actually varies in operation, by quite a bit.
I thought about rollers, realized I would need to reshape the lobe too....It sure would work, but for me, it's too much work....*LOL**..*EB

Wow! sounds interesting, but can I bolt it to my 22re? <img src="/forums/images/graemlins/drunk.gif" alt="" /> LOL
If you're in the field I guess you know about this site:
http://www.eng-tips.com/gthreadminder.cfm/lev2/6/lev3/35/pid/71
I enjoy reading some of the ideas there. I think there was some thread about spherical valves recently. I've been fascinated with this new BMW engine with no throttle and the servo motor that controls the cam lift instead.

Jay

>>>*That is fascinating stuff, makes me wish I was young again and could remember all the stuff I forgot!
There was some discussions about camless engines at the Superflo conference a few years ago.
There was also a design at a tech show in Chigago about 15 years back that was actually built and displayed. That one used servos to operate a conventional valve, rather than a cam and pushrod design.
I never heard more about that one. *Keep us posted on what you can, the potential is enormous, thanks!...*EB

Engbldr (or anyone else for that matter)-

Why does decking the head change the cam timing?

its a measurement thing, the chain is x" long and figured to fit around the crank and cam gears. By decking the head and or block you are reducing the distance from centerline to centerline of the crank shaft and cam....creating slack. Not enough slack that you can move to the next tooth and have the tensioner pickit up, but enough to retard the cam slightly. Lets say the head is cut .020"....well you just made the chain .040" too long. In the 22R-EB Gen 1 motor the retarded cam timing actually boosted its power and widened its RPM range, but that head eventually cracked out...stock dimensioned head did fine too. Hope that doesnt confuse you any more.

~Darin <img src="/forums/images/graemlins/baby.gif" alt="" />