i recently did a few mods on my a14 which include a 290 duration 11.5mm lift camshaft, twin hitachi su carbs, 7kg flywheel, h75 head with 2mm taken off and ports flown & match ported to su manifold. i can't seem to get the rockers to stop making a noise, while driving and idling you can hear them inside the cab very clearly. i checked the oil pressure and it's all good. any ideas to this problem? the gap is set to 0.35 according to the nissan specs

How exactly did you do the tappets (procedure)? You might have set them to the right gap but did you do set them when the followers were off the lobe of the cam (TDC/BDC)?

That's a big cam by the way

i did set it when off the lobe, turned the engine after every tappet was set. i'm thinking they might have gotten a bit loose because the other problem started 2 weeks back, it use to rev up like a monster but now once you start revving up or going past about 120 km/h it starts puffing at the exaust, not a lot but i can feel it holding back a bit. other thing i'm thinking is that the should be set differently because i took 2mm off the head?

The setting of the tappets shouldn't be influenced by how much the head has been milled, the adjusters will take up the excess. I THINK if anything the valves will open a little further with the extra milling of the head as the distance from the cam centreline and the pivot point of the rocker arms (rocker shaft centreline) has been reduced, i don't think this would be the case though if you've set the tappets again.

Have you checked if the pushrods are straight? Big spring pressures on the larger capacity A-series are a no-no as their pushrods are longer and therefore more prone to flex and bending. The smokey factor is an odd one though and sounds like it may be something else.

The other thing is if you have wiped the cam lobes...

the funny thing is it was standing for a week due to the starter being broken and when i fixed it and went for a drive it started with the rev problem, its not smoking on the exaust it has like a small backfire sound but still revs up if i keep it to the floor. i'm running sigle valve springs atm which revs up fine for me, so propably wont go to double spings as i would just rev it till it breaks...

if the cam lobes was wiped it would propably affect idling i think, but idles fine and revs clean when standing still

I'm not sure then. It might be something else altogether. But a wiped cam lobe or lobes wouldn't be as noticeable as you think, the lobes are lifting as usual except they may lift less meaning they are closing earlier or opening later, the loss of material off the lobe peak would mean the chattering will begin due to the excess space that has developed. I think you might get some popping as well due to the valve timing being out of order.

The only other things that come to mind are timing and the springs binding. But the timing wouldn't make a chattering noise although it would affect performance.

Spring binding could affect performance but not sure if it would be that audible.

Not sure dude. When you run it at idle are you absolutely positive the noise is coming from the rocker assembly?

i'm sure it's the rockers. i'll check the carbs after work as well, as iit seems there is some flooding going on when it stood for a while, might be a leaking float or float level that not right, i think it might be running out of feul at hig revs and then the rockers needs to be set again definetly. will climb in and check tonight. will post the problem once sorted out. thanks for the help and info. much appretiated

rocker pedestal bolts tight?

If the valve lash is a little too loose, the tappets make lots of noise.

And with an aftermarket cam, it might require more lash. I would ask the cam vendor for their recommendation.

Or just reset the valve lash. Make sure it is to spec (0.013 inch cold).