which opens first???????

[snailpower302]

At tdc and you turn the motor over clockwise ( on the compression stroke) which valve opens first is it the intake valve or the exhaust valve? Trying to figure out if the cam is 180 out!!

 

[nmcgrawj]

The intake has to open to let fuel/air in to then compress it (both valves closed) then the exhaust opens to push it out with the intake following very close behind.

 

[joel5.0]

At tdc and you turn the motor over clockwise ( on the compression stroke) which valve opens first is it the intake valve or the exhaust valve? Trying to figure out if the cam is 180 out!!

If in compression stroke TDC, you would have to turn crankshaft CW close to 180° for the exhaust valve to start opening..... if you are in the exhaust/intake changeover cycle TDC, the intake would start opening immediately after you start rotating the crankshaft.

BTW... don't you mean the distributor? If you install the cam 180° off, using the cam sprocket as the reference, it would be the same as installing it "dot-to-dot".