Zkrazy Posted December 2, 2009 Share Posted December 2, 2009 I'll try to keep this short. I have an E31 head with 280 valves and an Electromotive cam. Got it used, tore it apart and everything checked out good. When it ran it made a little valve train noise though, especially without a load at about 2500rpm. It ran great though and the engine revved quick up to 7k. Then my head gasket blew. (Lesson: don't buy cheap head gaskets from World Pac, it didn't have all the coolant holes) I had the head shaved .010 and the block has also been shaved .004. I installed a .015 set of cam tower shims and equally bigger lash pads (manual labor) to restore cam timing. It's almost perfect, not all the way to the right but just a little overlap between the notch on the sprocket and the mark on the tower on the #2 hole. After installing the shims I got the cam to spin the same as before I removed the towers, but I didn't have a cam tower bolt torque spec. The bolts didn't feel very tight coming apart but one side is shared with the head bolt. Anyone know the torque spec? Now it doesn't rev past 6k, gets there a little slower, and the exhaust note sounds flat. I'm thinking removing the cam towers has something to do with it. The valves also have a little more noise now. I did a search here about valve adjustment and found pics of taking the measurement with the spring installed. Then I found a pic of someone measuring without the spring.......... I've always done it with the spring removed, and have always had a little noise. I also found a few people mention .007" for the intake, while my manual says .008", it's pic shows with the spring. I did the adjustment without the spring, then put it on and rechecked it and the feeler wouldn't fit anymore. So I'm thinking I'll just try it with the spring on and see what happens but I wanted to see how other people do it and what their results are. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted December 3, 2009 Share Posted December 3, 2009 It's almost perfect, not all the way to the right but just a little overlap between the notch on the sprocket and the mark on the tower on the #2 hole. Now it doesn't rev past 6k, gets there a little slower, and the exhaust note sounds flat. I'm thinking removing the cam towers has something to do with it.Which hole was the cam gear mounted on before when it pulled to 7k? I'll guess it was #1 and you've reassembled with the cam timing advanced resulting in the power peak being moved to a lower rpm. Or perhaps you put the chain back on 1 tooth off? It sounds like somehow you have the cam timing advanced now. Quote Link to comment Share on other sites More sharing options...
Zkrazy Posted December 3, 2009 Author Share Posted December 3, 2009 The gear was at #1 and a little to the left of the notch, now it's at #2 and a little to the right. Based on the manual it should be to the right, right? Do I adjust valves with or without the spring, and .007 or 8 for the intake? Quote Link to comment Share on other sites More sharing options...
Zmanco Posted December 3, 2009 Share Posted December 3, 2009 The gear was at #1 and a little to the left of the notch, now it's at #2 and a little to the right. Based on the manual it should be to the right, right?IIRC in a perfect setup the bar should be in the middle of the notch. But since you were happy with the performance before the HG blew, why not set it up the way it was? Do I adjust valves with or without the spring, and .007 or 8 for the intake? IIRC, the spec is .008 cold for the intake valve with the spring removed. But if you're hearing noise with a non-stock cam, I would suggest you also check the wipe pattern. It's likely that is the main source of noise and you're a) not going to get rid of it by adjusting the valves, and may damage the cam and/or followers over time. Quote Link to comment Share on other sites More sharing options...
PandaZ Posted December 5, 2009 Share Posted December 5, 2009 Yeah the notch and groove should line up central. When you say spring removed, do you mean the mouse trap? For a standard to mild cam, 0.008" IN & 0.010" EX is the factory settings, (mouse trap on), but for big cams 0.010" IN & 0.012" EX is used. You can cheat if your stuck using a std cam for short distance stuff only (hillclimbs, motorkana...) by using .006" IN & .008" EX. But as Zmanco suggested, use for bearing blue and check the wipe pattern on your rocker pads! Also ive always thought that removing your cam towers is an absolute no no! (I had 80thou off one of my heads once and managed to adjust for it without removing the towers to shim them) Quote Link to comment Share on other sites More sharing options...
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