Welp, I did my valve lash today, and Gnarly, you get a gold star!
As a reminder this is a new engnbldr Street RV head with a new 261C cam. Reused the rockers as they were in perfect shape and just got polished up a bit.
All exhaust valves and two of the intake valves were tight by 001. It should be no surprise that the 1 and 4 intakes were at spec, considering they will actually be a bit loose if the base circle technique is not used (which i doubt it was.)
Now, for the really surprising part, after I got everything to spec (used base circle on 1 and 4 intake) and buttoned her back up, my idle RPM was sitting at 1350. That's a good 500 higher than it was set before. Taking her for a test drive I am feeling noticeably more low end power, and seemingly more midrange judging from a couple hills I pulled. She kinda wants to jump off the line now. Above 3000 seems to be about the same (which is to say, awesome ) Will need to road test a bit more to confirm.
Now, another surprise, I can get the idle down to 750 - where it should be - without the rough shaking that was happening before. I felt before that I was getting a miss down that low so I set the idle to 850 or 900 to smooth it out. That is no longer necessary. The idle sounds a lot smoother too, whereas before there was sort of a "chug" happening, which, though it sounded cool, is not normal for a 22re in my experience.
So, my feeling here is 001 off on the lash is probably not enough to burn a valve and isn't dangerous (Although I guess I really have nothing to back that up...). Clearly however, there are massive performance differences to be had with this cam. I wonder how much of the hate for this cam could be resolved with a very precise lash setting.
Other note, the lobes definitely do not line up perfectly with the rocker pads. All of the pads had complete contact - none were going past the edge of the lobes - but several were pretty close to the edge. I do not have a stocker to look at right now so I am not sure if they are supposed to be perfectly centered? In any case I can't see it being a problem. My cam lobes seem to be in perfect shape, no scoring or discoloration or anything. I guess I got the break-in correct.
My machinist who built the motor never said anything about the lobes, and he builds a lot of 22res, so I wonder if they are just never really centered and it isn't a problem.
Welll.. I’m not sure I deserve a GOLD star… Thank you.
Ohhh... Wait…. Didn’t a couple of experts here say the valve lash doesn’t go “tight”?
I spent many hours testing and experimenting with the valve lash on my 1985 22R, so all I have to go on is just MY limited experience.
And yes, valve lash adjustment CAN affect performance.
Here's a quick FAQ: http://www.cpgnation.com/forum/threads/comp-cams-quick-tech-video-how-to-set-valve-lash.4986/
I think H8PVMNT will back me up on this… the carb’d engines respond to very small changes that you can feel in your butt dyno. The 22RE, with mamaCPU and her over-priced sensors tend to “control” the changes, and programmed to modulate the best gas mileage and emissions control, to name few things she does. I'm not saying the 22RE is bad, I’m saying from my experience I could feel the changes I made with my 22R WAY more than I can feel the changes with both of my 22REs.
So what lash did you end up with?
Have you been able to calculate any accurate gas mileage?
On idle RPM, my 22RE, thus far likes the idle about 900, and I’m OK with that. And I believe that is because of the overlap in the 261C cam.
I'm very glad you are getting what you are out of that engine and combo…. Great job!! I'm envious at this point.