While on TDC 2 of my exhaust valves are slightly open and same with the intake valves

[newtodsm97gst]

While on TDC 2 of my exhaust valves are slightly open and same with the intake valves, is this normal?

 

[Dsmkauai]

First off tdc on which piston? And are the timing marks lined up correctly? And congratulations your my 1k tech post!!! wait how do you have the head off the car with no cams?

 

[newtodsm97gst]

First off tdc on which piston? And are the timing marks lined up correctly? And congratulations your my 1k tech post!!! wait how do you have the head off the car with no cams?

timing mark are on and 2 exhaust valve is slightly open. the head is off and cam are still attached.

 

[truesk83r]

Depending on the cylinder. Not all valves are shut at TDC. If the ones that should be shut are opened, make sure the lifters are bled. I forgot to bleed my lifters when I installed 272 cams and I ended up bending a couple valves and breaking a couple guides, because all the valves wanted to stay open, at the same time.

 

[Dsmkauai]

But you have the head off the car in the picture correct? Looks like your guides are sticking or possible valves are alittle bent. Why is the head off the car? Did you get low compression test numbers?

 

[newtodsm97gst]

i'm doing a rebuild on my block and when I was cleaning the head I notice its slightly open. i'll try bleeding the lifters.

 

[luv2rallye]

Been wondering how long it would take before someone finally made a post on this. Looks like it took 23 years!

Our turbo engines have "valve overlap" which means at TDC between exhaust and intake strokes both the intake and exhaust valves are slightly open. See: http://www.dsmtuners.com/forums/attachment.php?attachmentid=128779&d=1318449301.

And if you don't understand the diagram: http://www.dsmtuners.com/forums/newbie-forum/444971-degrees-close-valves.html#post153071377.

 

[miguelmcv]

It meant to be like that.

2 valves should be a little open, you are good,

 

[newtodsm97gst]

Thank god.. This rebuild is costing me so much money that i alloted and so much time.. Thsnks guys..

 

[donniekak]

The only way to have all 16 valves closed at the same time is to remove the cams.

 

[truesk83r]

yeah that's what I meant. If you look at the timing circle chart thing, valves begin to open before the pistons reach the bottom of the stroke.