Valve Lash and Cam Timing
#1
Senior Member
MASTER BUILDER
Thread Starter
Join Date: Aug 2007
Location: Iowa - USA
Posts: 218
Valve Lash and Cam Timing
How does the valve lash effect the cam's valve timing? For example, i bought a engine with a Lunati solid lifter cam. The valve lash for both intake and exhause is.030. What does this do for the engine?
#3
Senior Member
DYNO OPERATOR
Join Date: Jan 2004
Location: central Illinois
Posts: 459
valve timing
Are you sure about that? Loosening the valve lash makes the cam seem smaller, which helps bottom end performance. Tightening makes rthe cam seem larger, which helps the top end. That has been my experience.
If you play with lash up to .004 looser and tighter, you may find minor improvement. It will also tell you if cam you have is too large or small if it wants lash set different than factory setting. I set lash .006" tighter cold than hot specs for BBC with aluminum heads and iron block.
If you play with lash up to .004 looser and tighter, you may find minor improvement. It will also tell you if cam you have is too large or small if it wants lash set different than factory setting. I set lash .006" tighter cold than hot specs for BBC with aluminum heads and iron block.
#4
Senior Member
DYNO OPERATOR
Join Date: Apr 2008
Posts: 504
Wrong
Originally Posted by bowhay
looser valve lash will give u more top end, tighter will give u more torque of the bottom
Bruce
#5
Senior Member
RACING JUNKIE
Join Date: Sep 2007
Posts: 4,137
Re: Wrong
Originally Posted by TopspeedLowet
Originally Posted by bowhay
looser valve lash will give u more top end, tighter will give u more torque of the bottom
Bruce
X2....I know first hand about the roller damage. I used to think they would tighten up when HOT...of course this is 100% wrong but back then I didn't know...I set them cold just a little loose thinking they would be just right when hot....it's the opposite.I busted a roller lifter(and a block) after 20 something passes. live and learn.
#8
This is how I adjust valves. The website has excellent info on valve adjustments but there is too much info to list here.
http://www.centuryperformance.com/ad...h-spg-149.html
Valve Adjustment Procedure - The Quick and Accurate Way:
First, view this little chart below for Small and Big Block Chevy Engines that I made and see if you can understand it. There is more of an explanation below the chart. For other engines you will use the firing order that matches your engine to create a similar chart. This chart is based upon "opposite" cylinders of your firing order. (see below)
Intake Valve Adjustment: ENGINE OFF!
■with #1 cylinder Intake Valve at full valve lift .... Adjust #6 Intake Valve
■with #8 cylinder Intake Valve at full valve lift .... Adjust #5 Intake Valve
■with #4 cylinder Intake Valve at full valve lift .... Adjust #7 Intake Valve
■with #3 cylinder Intake Valve at full valve lift .... Adjust #2 Intake Valve
■with #6 cylinder Intake Valve at full valve lift .... Adjust #1 Intake Valve
■with #5 cylinder Intake Valve at full valve lift .... Adjust #8 Intake Valve
■with #7 cylinder Intake Valve at full valve lift .... Adjust #4 Intake Valve
■with #2 cylinder Intake Valve at full valve lift .... Adjust #3 Intake Valve
Exhaust Valve Adjustment: ENGINE OFF!
You will notice that this is the same procedure and sequence as the intake valves listed above. Only now you are adjusting ONLY the exhaust valves the same way.
■with #1 cylinder Exhaust Valve at full valve lift .... Adjust #6 Exhaust Valve
■with #8 cylinder Exhaust Valve at full valve lift .... Adjust #5 Exhaust Valve
■with #4 cylinder Exhaust Valve at full valve lift .... Adjust #7 Exhaust Valve
■with #3 cylinder Exhaust Valve at full valve lift .... Adjust #2 Exhaust Valve
■with #6 cylinder Exhaust Valve at full valve lift .... Adjust #1 Exhaust Valve
■with #5 cylinder Exhaust Valve at full valve lift .... Adjust #8 Exhaust Valve
■with #7 cylinder Exhaust Valve at full valve lift .... Adjust #4 Exhaust Valve
■with #2 cylinder Exhaust Valve at full valve lift .... Adjust #3 Exhaust Valve
http://www.centuryperformance.com/ad...h-spg-149.html
Valve Adjustment Procedure - The Quick and Accurate Way:
First, view this little chart below for Small and Big Block Chevy Engines that I made and see if you can understand it. There is more of an explanation below the chart. For other engines you will use the firing order that matches your engine to create a similar chart. This chart is based upon "opposite" cylinders of your firing order. (see below)
Intake Valve Adjustment: ENGINE OFF!
■with #1 cylinder Intake Valve at full valve lift .... Adjust #6 Intake Valve
■with #8 cylinder Intake Valve at full valve lift .... Adjust #5 Intake Valve
■with #4 cylinder Intake Valve at full valve lift .... Adjust #7 Intake Valve
■with #3 cylinder Intake Valve at full valve lift .... Adjust #2 Intake Valve
■with #6 cylinder Intake Valve at full valve lift .... Adjust #1 Intake Valve
■with #5 cylinder Intake Valve at full valve lift .... Adjust #8 Intake Valve
■with #7 cylinder Intake Valve at full valve lift .... Adjust #4 Intake Valve
■with #2 cylinder Intake Valve at full valve lift .... Adjust #3 Intake Valve
Exhaust Valve Adjustment: ENGINE OFF!
You will notice that this is the same procedure and sequence as the intake valves listed above. Only now you are adjusting ONLY the exhaust valves the same way.
■with #1 cylinder Exhaust Valve at full valve lift .... Adjust #6 Exhaust Valve
■with #8 cylinder Exhaust Valve at full valve lift .... Adjust #5 Exhaust Valve
■with #4 cylinder Exhaust Valve at full valve lift .... Adjust #7 Exhaust Valve
■with #3 cylinder Exhaust Valve at full valve lift .... Adjust #2 Exhaust Valve
■with #6 cylinder Exhaust Valve at full valve lift .... Adjust #1 Exhaust Valve
■with #5 cylinder Exhaust Valve at full valve lift .... Adjust #8 Exhaust Valve
■with #7 cylinder Exhaust Valve at full valve lift .... Adjust #4 Exhaust Valve
■with #2 cylinder Exhaust Valve at full valve lift .... Adjust #3 Exhaust Valve
#9
Member
JUNIOR BUILDER
Join Date: Jun 2004
Location: lake luzerne n.y.
Posts: 87
Originally Posted by fla1976
This is how I adjust valves. The website has excellent info on valve adjustments but there is too much info to list here.
http://www.centuryperformance.com/ad...h-spg-149.html
Valve Adjustment Procedure - The Quick and Accurate Way:
First, view this little chart below for Small and Big Block Chevy Engines that I made and see if you can understand it. There is more of an explanation below the chart. For other engines you will use the firing order that matches your engine to create a similar chart. This chart is based upon "opposite" cylinders of your firing order. (see below)
Intake Valve Adjustment: ENGINE OFF!
■with #1 cylinder Intake Valve at full valve lift .... Adjust #6 Intake Valve
■with #8 cylinder Intake Valve at full valve lift .... Adjust #5 Intake Valve
■with #4 cylinder Intake Valve at full valve lift .... Adjust #7 Intake Valve
■with #3 cylinder Intake Valve at full valve lift .... Adjust #2 Intake Valve
■with #6 cylinder Intake Valve at full valve lift .... Adjust #1 Intake Valve
■with #5 cylinder Intake Valve at full valve lift .... Adjust #8 Intake Valve
■with #7 cylinder Intake Valve at full valve lift .... Adjust #4 Intake Valve
■with #2 cylinder Intake Valve at full valve lift .... Adjust #3 Intake Valve
Exhaust Valve Adjustment: ENGINE OFF!
You will notice that this is the same procedure and sequence as the intake valves listed above. Only now you are adjusting ONLY the exhaust valves the same way.
■with #1 cylinder Exhaust Valve at full valve lift .... Adjust #6 Exhaust Valve
■with #8 cylinder Exhaust Valve at full valve lift .... Adjust #5 Exhaust Valve
■with #4 cylinder Exhaust Valve at full valve lift .... Adjust #7 Exhaust Valve
■with #3 cylinder Exhaust Valve at full valve lift .... Adjust #2 Exhaust Valve
■with #6 cylinder Exhaust Valve at full valve lift .... Adjust #1 Exhaust Valve
■with #5 cylinder Exhaust Valve at full valve lift .... Adjust #8 Exhaust Valve
■with #7 cylinder Exhaust Valve at full valve lift .... Adjust #4 Exhaust Valve
■with #2 cylinder Exhaust Valve at full valve lift .... Adjust #3 Exhaust Valve
http://www.centuryperformance.com/ad...h-spg-149.html
Valve Adjustment Procedure - The Quick and Accurate Way:
First, view this little chart below for Small and Big Block Chevy Engines that I made and see if you can understand it. There is more of an explanation below the chart. For other engines you will use the firing order that matches your engine to create a similar chart. This chart is based upon "opposite" cylinders of your firing order. (see below)
Intake Valve Adjustment: ENGINE OFF!
■with #1 cylinder Intake Valve at full valve lift .... Adjust #6 Intake Valve
■with #8 cylinder Intake Valve at full valve lift .... Adjust #5 Intake Valve
■with #4 cylinder Intake Valve at full valve lift .... Adjust #7 Intake Valve
■with #3 cylinder Intake Valve at full valve lift .... Adjust #2 Intake Valve
■with #6 cylinder Intake Valve at full valve lift .... Adjust #1 Intake Valve
■with #5 cylinder Intake Valve at full valve lift .... Adjust #8 Intake Valve
■with #7 cylinder Intake Valve at full valve lift .... Adjust #4 Intake Valve
■with #2 cylinder Intake Valve at full valve lift .... Adjust #3 Intake Valve
Exhaust Valve Adjustment: ENGINE OFF!
You will notice that this is the same procedure and sequence as the intake valves listed above. Only now you are adjusting ONLY the exhaust valves the same way.
■with #1 cylinder Exhaust Valve at full valve lift .... Adjust #6 Exhaust Valve
■with #8 cylinder Exhaust Valve at full valve lift .... Adjust #5 Exhaust Valve
■with #4 cylinder Exhaust Valve at full valve lift .... Adjust #7 Exhaust Valve
■with #3 cylinder Exhaust Valve at full valve lift .... Adjust #2 Exhaust Valve
■with #6 cylinder Exhaust Valve at full valve lift .... Adjust #1 Exhaust Valve
■with #5 cylinder Exhaust Valve at full valve lift .... Adjust #8 Exhaust Valve
■with #7 cylinder Exhaust Valve at full valve lift .... Adjust #4 Exhaust Valve
■with #2 cylinder Exhaust Valve at full valve lift .... Adjust #3 Exhaust Valve
The easiest way I have been taught to adjust valves is from reher morrison. If you take one cylinder at a time, when the exhaust valve begins to open you adjust the intake valve, Rotate the motor and when the intake valve begins to close adjust the exhaust valve.
I also found that when I set the lash cold i need to go back around once the motor warms up and adjust them again because it changes significantly. I always check them now when the motor is hot.