Rotary Valve Cover Uneven Wear?

[george0029]

Hello All,

I have a 2002 GTI LE into which I'm swapping a new SBT 717, but I'm a bit worried about the rotary valve cover. It isn't gouged or grooved anywhere, and the surface seems relatively smooth, but it seems to be wearing unevenly. Looking at the outside edge, the surface appears worn deeper near the intake manifold holes than elsewhere on the valve. Is this normal? I'd prefer to avoid replacing it, but I'm worried that uneven wear could cause some leaking between the two sides. Any input is appreciated, pics attached. Thanks Guys!

 

[Dr Honda]

Normal... but if it's excessive, the cover should be changed.

 

[george0029]

According to the manual, rotary valve clearance must be 0.30mm +/- 0.05 mm. My 0.35mm feeler gauge was a snug fit toward the center of the rotary valve, but clearance on the outside (near the uneven looking wear) was close to 1mm. Guess I'll have to order a RV cover from SBT for $120 shipped...... unfortunately they're out of stock and will take 3-5 days to ship, not to mention being closed on weekends.

I'm wondering what could have caused such uneven wear. I blew my motor presumably due to a lean condition, which i attribute to a crack in the case on the rotary valve surface. The case broke at the upper left bolt that holds the RV cover in place, and cracked the surface of the rotary valve as well. This is the only reason I can come up with for such ridiculous wear resulting in a clearance that big. Never had any hard-starting issues though, so I'm puzzled. Any thoughts????

 

[Dennis]

Is the rotary valve nice and flat or is it warped/bent?

A warped/bent rotary valve would cause case and valve cover wear.

 

[OldSchool]

As it was explained to me, the wear is caused over long periods of use due to the edge of the valve itself being the area most likely to flex under constant vacuum and pressure around the ports themselves. Some French guy named Jean Luc told a small group of us that info during advanced technician training in the mid 90's, in Canada.

This individual also took exception to guys referring to Bombardier as Bomb-a-deer rather than Bombard-ee-ay. One guy called them Bombard-ee-er. Jean Luc yelled "you fools... eet ee-is BOMBARD-EE-AY!"

 

[george0029]

The rotary valve wasn't noticeably warped or bent. However, if the rotary valve and cover have never been replaced in the nearly 12 years this motor has been running, it would be entirely understandable that it would be worn. Might as well replace it and not have to worry.

I'm hoping a dealer in the area will have one in stock, because that's the final engine component I'm waiting on, and like I said earlier SBT is out of stock.