Started back up on the engine by remeasuring my pushrod length and lifter preload. I discovered that fully torquing the heads down has a significant effect on gasket thickness, and thus the required pushrod length - much more so than I was expecting. When I measured them before I only "snugged" it down tight because I was leery of what multiple torque sequences might do to the sealing ability of gaskets that are $80 a piece. But when my measurements weren't repeating with what I took last time I said f*ck it and torqued it down. In some cases my measurements changed about .030".
Anyways....onward with measuring lifter preload. When I tried this before I was having problems as I snugged the rocker pair down with the indicator tip wandering around the pushrod cup, fucking up my measurements. To try and help solve this I bought a pointed carbide indicator tip, which I ground/polished into even more of a point. This would locate it positively in the oil hole on the pushrod side of the rocker.
This helped to make my measurements much more repeatable.
Now with my pushrod lengths taken, I could test the sample push rods I got from trend and attempt to measure an expected lifter preload based on the difference between what I actually need and what I actually have. This was in an effort to more or less show that my measurements are comparable to the measurements they take at Trend. Results were all over the place, and at the moment I can't really say why. I tested the expected preloads with a 7.700 rod from Trend.
- Cyl 2 intake: Expected - .037. Measured - .038. Good.
- Cyl 4 intake: Expected - .030. Measured - .020. What.
- Cyl 6 intake: Expected - .040. Measured - .023. Wat.
- Cyl 8 intake: Expected - .022. Measured - .015. Eh.
At the end of the day - I have no control over what Trend sends me. I'm going to all this trouble to minimize measurement error and quadruple check everything, and then they could send me a pushrod that's out of spec. Say 0.009" short of my spec'd length. Like they did with the 7.730 rod I ordered. Which was supposed to be cut within +/- 0.001". WTF
Am I the only one who checks this shit? Short of ordering a whole slew of slightly varied lengths to accommodate all the measurement / machining error, I really don't know if there's a bulletproof way through this.
This has been the most frustrating part of the build to date BY FAR.
While I figured out how to handle all of this, I decided to get out and practice some MIG welding in the garage. T-joints on 1/8" steel. I was disappointed to find that my little HH 140 wasn't powerful enough to really burn it in nice - the toes of the weld seemed to be pretty cold even with the machine maxed out, a reduced travel speed, short stickout, etc. So I'll be looking to source a more capable 230V machine in the near future, but figured I could get some decent practice in regardless.....at least work on hand consistency. This is about the best I could do - pulling from left to right and tracing out small "e's" with a little pause at the top of each loop. C25 gas and 0.023" wire. Might have worked better with 0.030" but this is what I had.
Like I said, the welds are cold but I beat the hell out of a few of the joints like they owed me money and nothing let go.
TIG welder coming later this week! Gotta get power run and another bottle before I actually melt stuff with it though :(
