Hi,

I have a friend of mine who is trying to track down some problems.
When going from N to D (A4) the car bogs and sometimes it even stalls. In 3rd gear at WOT there's sometimes a massive drop in the RPMs, it sounds like a hesitation/bog, but ignition wise it's all new. He has checked everything that could be related to this problem, but everything's fine. This problem has developed after a spring/Roller rocker install, his lifters are stock.
He set the valvelash to 1/2 turn + a little bit more (probably an additional 1/16 turn) and tightened it down.
What do you think? For me it sounds like it's too much...
Can too much pre-load can cause simptomes like that? What made made suspicious, is that he's missing a good amount of power after the install.
Thank you guys!

 

I don't think 1/2 turn should cause a problem unless you were way up in the RPM range.

I'm running 1/2 turn past 0 lash and I spin to the stock limiter w/o problems.

 

If they are too tight, you would probably notice a fluttering or miss feeling at all rpms. If the springs are too much for the stock rockers, then that is going to cause some problems, but it would be the opposite effect. The lifters would not be allowing the valves to open all the way. That would very much decrease power.

 

Thanks for your input, guys!