Hi Guys / Gals,

I'm getting ready to do my valve lash this weekend (first time) and was wondering if anyone has ever doing the valve lash while turning the motor clockwise?

Normal instructions say you should turn the motor CCW (as it runs) and do the valve lash following the firing order (1-3-4-2). Afterwards you're to retorque the crank pulley bolt to 130 ft-lbs.

For several reasons I don't want to have to deal with the last step. My thinking was I could turn the motor clockwise and check the valves in reverse firing order (1-2-4-3)... That way I'm not loosening the crank pulley and I still hit the TDC's correctly?

Just thinking about it I can't think of any reason that would be a bad idea?

ohhhh.... Unless the ramp rates on the cams (mine are Skunk2 Pro 2) are different opening vs closing (actually, I know they are) and thus the lash should be done as the engine turns.

Well, I just answered my own question, positing this to hopefully stop someone with a similar thought process from screwing up their valve lash....

Unless I'm wrong again since at TDC combustion the cam is at the zero lift portion????

 

Stick to CCW.

You are not very likely to loosen the crank pulley bolt. It almost always takes a torque multiplier or a real strong impact gun to break that bolt free.

The timing belt tensioner only works to keep the belt the proper tension when it is turned CCW. The tensioner doesn't keep the belt tight when going clock wise and there is a much increase chance the cams will not turn in sync with the crank. Of which means an increase chance of valves kissing pistons as you hand crank it.

 

You will not even be close to loosening the crank bolt. You can pull the spark plugs and it will be even easier to turn the crank.

 

So should I even bother with re-torquing it?

I was thinking about it and actually the cam would be in the same orientation regardless of if you turn it CW and CCW.

So.... Other than the timing belt potentially skipping a tooth any other concerns?

 

If you are running a stiffer valve springs you are very likely to skip the timing doing it in reverse. Just do it like you're supposed to and have far less problems.

 

You're putting tension on the wrong side of the system so yes, you could potentially be out of sync and you could also skip a tooth. You should never turn your engine backwards for this very reason.

I've never ever ever heard of anyone accidentally loosening the crank pulley bolt... If it does it was about to fall out anyway and you should pat yourself on the back for finding it before it became a problem. If you are that concerned about it though, pull the spark plugs before you do your valve adjustment, that what you'll be working against on the the valvetrain and not the engine's compression.

 

Rotating the crank won't loosen the crank pulley unless you crank is super swoll and your arms are super swoll, one of them gotta give....

 

Well did it CCW as I'm supposed to, everything was good..... Untill the little f** bolt that holds the feeler gauges together came loose and fell into my engine.... Now I have to figure that out damnit

 

I'm glad you listened to everyone else about the CCW. I had written a reply to re-explain again how the timing belt can't possibly get loos CCW but how the cam can definitely not turn exactly at the same time CW due to the tensioner/waterpump pathway allowing the belt to go slack by design and figured you'd ignore it being you already "fathomed" the timing belt design couldn't possibly allow slack in either direction and scrapped my reply.

Now, the nut you dropped likely went down an oil return hole in the block so is sitting in the bottom of your oil pan.

If you take a picture of what hole the nut fell into, that can be confirmed. And advice can be provided from there.