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Well I guess I have a 521 project now...

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So after a 350 mile trip to california Eve's not doing so hot. Cyl 1 took a crap on my return trip hopes. 60 psi with 150ish in the other 3. Checked the valves and found the following



1 - <0.0015

2 - 0.005

3 - 0.003

4 - 0.008



1 - 0.010

2 - 0.010

3 - 0.010

4 - 0.010


I set the valves at .008 and .010 last fall, less than 1000 miles ago. Clearly something is causing the intakes to not hold their adjustments. Upon adjusting the valves I found I was out of adjustment on intake 1. Pulled the rocker off and found the contact surface was grooved from being in constant contact with the cam. It seems to me the brass valve seats are either sinking or being worn down moving the intake valves up the head thus dropping my valve clearances. I don't exactly have the time to rebuild the head right now so if it's avoidable I will make my best efforts. So here goes...hand polished the rocker pad and filed the jam nut thinner. Hopefully this will be at least good enough to get some compression back to cyl 1 and get me back home....



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all back together right now got enough adjustment out of the refinished rocker and thin jam nut. All clearances are 10 and 8 thou, and compression in cylinder 1 is back to normal. Too late to start her up but tomorrow morning will be moment of truth!





She's also got some small tune up stuff since I was in there. New oil pan gasket, fan belt, spark plugs and plug wires.

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She runs! I hope to be heading home tomorrow. I will have feeler gauges at the ready for quick checks haha.



PSA: this is not a permanent solution, if your datsun has this happen get new valve seats. This is one of the more janky fixes I've done and it's just to get me home.

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Haha well, I'm at a home away from home so I've been working in a garage but I'm away from most of my tools and more importantly in this case my spare parts. I have on other complete head. It's a W58 but it would work. I plan on swapping heads and rebuilding this one with steel valve seats when I get back.

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