I pulled the suspected bad lifter out last Friday night and had my brother stop by to look things over, since he knows  a lot more about engines than myself.  Ended up having a normal pattern on the bottom of the lifter, however, there was some question about the wear pattern on the cam lobe, what we could see of it. So, I put it all back together, doubled checked the lash and am going to monitor everything the best I can.  Spun the engine around with the plugs still out to build some oil pressure, and I could see the black Sharpie mark I put on #5I pushrod spinning quite well.  So that is good.  Go to start the engine and no spark.  Either not enough voltage to the Pertronix because I have been working the battery pretty hard, or it has crapped out all-together.  That's where I'm at.

Mike

It would be a factory P.I. intake, so very close to the CJ intake.

Thanks

How much "extra" lash does it take to send up a red flag that a cam/lifter is going bad?

We broke in the cam for the 445 in my Fairlane Hardtop with no issues.  Solid flat tappet, nitrated cam, EDM Crower lifters, break in oil and inner springs removed.
2-2500 rpm for 20 minutes, or so. All went good. Currently, I am at break-in plus about 50 street driven miles. Easy on the rpm's, but plenty of accel and de-cel.

This past weekend, we pulled the rocker assembly's and swapped out the break-in springs for the ones called for by the cam we are using.  Everything looked fine upon inspection and going back together.  I run through the valve lash adjustments and all seem fine, most are a hair loose...a couple .001, 3,4,5 thou. maybe, from their original setting. I think, okay, wearing in a little.  I reset them and move on.  I got to #5 Intake and it was .025 off it original setting.  I was setting them at .016 and this measured .041. 

Should I reset it and put some miles on the car, and remeasure. Or should I dig into it now?  As of now, I have not cut open the oil filter.  I am working on getting a cutter.

Anyones thoughts appreciated.

Mike

What input shaft are you using in your Toploader? I ask because in my most recent build,  my 4sp. fought me like no other trans ever had before regarding getting everything seated in the bell, disc and pilot. Try to put it in, pull it out, back in, pull it out. Pull the disc out, test the splines in the disc on the bench...no problem falls right on. Scat crank like yours, aftermarket big spline input but with the small block pilot tip. Only way you could get a wide ratio in a big spline, at the time.

After back and forth emails to Scat and some other checks, I am 99.44% sure that this combination is okay.  I have used the same crank and input in other cars and never had an issue.  Your gremlins have got me wondering all over again.  Curious to hear what you find.

Mike

Knocking on a 12.-- something pass. Pretty impressive given those manifolds. Looks like some nice cool October air, too. That always helps. A little more tweaking and it will be in the twelves for sure. Those repop tires start hooking better the more you beat the crap out of them.

Mike

Custom pushrod lengths don't affect rocker arm geometry.

Rocker arm geometry is how the rocker arm interfaces with the valve tips.  Changing pushrod length on an FE doesn't affect rocker arm geometry, but for whatever stand height (which does affect geometry) you settle on, then the pushrods have to obviously work between the rockers and the lifters.

Simply put, rocker arm geometry is based on what kind of pattern you get on the valve tips, plus how much lift you gain/lose because of the geometry you end up with.  If the rocker arm tip rides the intake side of the valve hard, or the exhaust side of the valve hard, then you can get increased valve guide wear and reduced net lift.   Also, if you have a wide pattern, you're losing lift because the rocker arm tip is spending too much time moving across the valve tip instead of translating motion in making the valves go down. 

All in all, you want to try to have as narrow of a pattern as you can, somewhere near the center of the valve tip.

At what point does the width of your valve tip pattern warrant messing with raising or lowering your stand heights? I have read 12% to 15% of your pattern width to your cam lift. Would everyone here agree? I am at about 16-17%, worth messing with on a street motor?

Mike

Yeah, great pictures. Thanks for sharing your build. You have great attention to detail.

Mike

Not sure if this is someone's video that is on this site, but it popped up on YouTube.

https://www.youtube.com/watch?v=_aSy9hu2Gas

At the very end, you can see the pass that John Nagoda was asking about.

Mike