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Wed Jul 09, 2014 8:50 am

Hi there,

following the advice given on a previous post....

http://www.thesamba.com/vw/forum/viewtopic.php?t=5...highlight=

I have reset my valve clearances to zero due to moly pushrods. When I took the my van out on a 120 mile trip, the engine ran fine, but the next day I drove it a couple of miles and found that it performed terribly. It misfired when in low revs and hated being in third or fourth gear, struggling up any sort of an incline. I expected that it would be a little loud before the engine warmed up, but this was a horrible lack of power as if the timing was out.

I will hope to check the clearances again by the end of the week, as my van is stored a few miles away from my home, but in the meantime does anyone have any info or can shed light as to why this may happen?

Thanks.

Wed Jul 09, 2014 9:17 am

You sire you got chrome Molly's?

I have a 2110 in a 62 split that runs steel pushrods. I set them to .006. Little loud but no issues.

You can try setting your exhaust valve lash to .002 and rest to loose zero. Recheck timing, dwell and set idle mixture.

Wed Jul 09, 2014 9:30 am

The engine is 1641cc recon unit, but that was all the info I have had on it, but for some reason have always believed them to be cromoly and not steel, but now beginning to doubt it.

When I took the rocker covers off to check them for the first time, there was no clearance. I couldn't squeeze a feeler in there at all. In fact some of them were so tight, there was no movement at all. So zero lash is actually looser than it had been before.

Don't think I could tell by looking at them if they were steel or not. I guess they're heavier?

Wed Jul 09, 2014 9:35 am

Umm. A magnet works great!! Chrome Molly is steel. Aluminum you will want clearance .006

Wed Jul 16, 2014 9:39 am

"Chrome-Moly" or "Chromoly" is simply steel with small amounts of alloying elements added, namely Chrome and Molybdenum, and then heat treated to get better strength, toughness than normal steel. See

http://ezinearticles.com/?Chrome-Moly-Tubing---This-4130-Tubing-is-Strong&id=1414397.

That said, Chromoly has virtually the same coeficient of expansion as steel. I fail to see why you would want to set the valve lash differently for the two materials, all else being equal.