Adjusting valve lash - Solid lifter
Thread Starter
Burning Brakes
Joined: Jan 2009
Posts: 922
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From: Delta BC
Adjusting valve lash - Solid lifter
I have seen a couple of methods to adjust valve lash on solid lifter motors. They are:
1) Starting with #1 cylinder, adjust intake just as exhaust is opening, then adjust exhaust just as intake is closing (EO IC). Repeat on every cylinder.
2) Bump motor until intake valve on #1 is fully open. Adjust intake valve on #6 cylinder as it will be at the bottom of the cam. Repeat the same with exhaust. Repeat the same with the opposite for every cylinder.
What do you prefer? Is there an even better method that I haven't seen yet?
Bob
1) Starting with #1 cylinder, adjust intake just as exhaust is opening, then adjust exhaust just as intake is closing (EO IC). Repeat on every cylinder.
2) Bump motor until intake valve on #1 is fully open. Adjust intake valve on #6 cylinder as it will be at the bottom of the cam. Repeat the same with exhaust. Repeat the same with the opposite for every cylinder.
What do you prefer? Is there an even better method that I haven't seen yet?
Bob
Le Mans Master
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From: Puget Sound
Race Director
Joined: Feb 2004
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From: CT
The only method that ensures the adjusting valve has the lifter on the heel of the cam is as follows.
With full lift on Adjust Valve
#1 Intake #6 Intake
#8 Intake #5 Intake
#4 Intake #7 Intake
#3 Intake #2 Intake
#1 Exh. #6 Exh.
#8 Exh. #5 Exh.
#4 Exh. #7 Exh.
#3 Exh #2 Exh.
Other methods can place some valves either before of after the base of the cam. The above method allows you to ajust to factory settings, or you can adjust tighter or losser if you want to move the power range around. Working in firing order sequence this method is easy to work.
With full lift on Adjust Valve
#1 Intake #6 Intake
#8 Intake #5 Intake
#4 Intake #7 Intake
#3 Intake #2 Intake
#1 Exh. #6 Exh.
#8 Exh. #5 Exh.
#4 Exh. #7 Exh.
#3 Exh #2 Exh.
Other methods can place some valves either before of after the base of the cam. The above method allows you to ajust to factory settings, or you can adjust tighter or losser if you want to move the power range around. Working in firing order sequence this method is easy to work.
Last edited by GCD1962; Dec 30, 2009 at 08:03 PM.
Team Owner
Joined: Mar 2003
Posts: 26,118
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From: Greenville, Indiana
This is the way I do it. Easy to keep track of where you are and you don't have to worry about long duration cams not getting adjusted with the lifter on the heel of the cam.
Pro
Joined: Nov 2009
Posts: 667
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From: Milpitas Calyfornua
As a young man in the 60's I remember very well a tool called the P & G Valve Gapper. I had seen cars where the valves had been adjusted with a feeler gauge and they may sound ok. Most people just do not have the fine touch for a feeler guage or often the lifter is not at bottom dead center on the cam Then you could take a P&G to it and the valves would sound like the purr of a well tuned sewing machine. I still have one in my tool box. Hard to find, but a really neat tool. They show up on Ebay from time to time. There were adapters that were required for different engines.
http://www.ctci.org/membership/Gilsg...alveGapper.htm
Roger
Calyfornua
http://www.ctci.org/membership/Gilsg...alveGapper.htm
Roger
Calyfornua
Race Director
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From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
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I use method #1 on everything. Works fine and is very repeatable.
I also set them cold so I know all are at the same temp. With aluminum heads I set them .005-.006" tighter than HOT spec.
JIM
I also set them cold so I know all are at the same temp. With aluminum heads I set them .005-.006" tighter than HOT spec.
JIM
Race Director
Joined: Nov 2002
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From: Taylor Michigan
I also have a P&G gapper tool we used a few times and then went back to the 1 st method
Last edited by Ironcross; Dec 30, 2009 at 05:38 PM.
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Team Owner
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Army
It is a 'touchy-feely' exercise. I set the valve lash cold to whatever the spec is..until I have light friction on both sides of the feeler gauge; then try to fit the next larger feeler gauge in the gap and it should not fit....then you have it...
Drifting
Joined: Jul 2000
Posts: 1,347
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From: Melbourne Australia
I have seen a couple of methods to adjust valve lash on solid lifter motors. They are:
1) Starting with #1 cylinder, adjust intake just as exhaust is opening, then adjust exhaust just as intake is closing (EO IC). Repeat on every cylinder.
2) Bump motor until intake valve on #1 is fully open. Adjust intake valve on #6 cylinder as it will be at the bottom of the cam. Repeat the same with exhaust. Repeat the same with the opposite for every cylinder.
What do you prefer? Is there an even better method that I haven't seen yet?
Bob
1) Starting with #1 cylinder, adjust intake just as exhaust is opening, then adjust exhaust just as intake is closing (EO IC). Repeat on every cylinder.
2) Bump motor until intake valve on #1 is fully open. Adjust intake valve on #6 cylinder as it will be at the bottom of the cam. Repeat the same with exhaust. Repeat the same with the opposite for every cylinder.
What do you prefer? Is there an even better method that I haven't seen yet?
Bob
But.........In method 1. your exhaust is set when the intake is nearly closed, not beginning to close as you stated
cheers
Jim
Le Mans Master
Joined: Nov 2008
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From: columbus oh
..good post just for clarification....set the intake when the exhaust STARTS to open....set the exhaust when the intake is FULLY OPEN AND STARTS to close.....fool proof on any mill......
Safety Car
Joined: Mar 2009
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From: Corpus Christi, TX
I use the method from the 1966 Chassis Service Manual for my L-72.
Firing on #1, timing mark at TDC adjust Exhaust 4 and 8; and Intake 2 and 7.
Rotate crank 180 degrees, adjust Exhaust 3 and 6; and Intake 1, 8.
Rotate crank 180 degrees (timing mark at TDC, firing on #6), adjust Exhaust 5 and 7; and Intake 3, 4.
Rotate crank 180 degrees, adjust Exhaust 1 and 2; and Intake 5, 6.
This technique should work on most factory SB cams as well because the lobe ramps are similar. It will work perfectly on most modern cams with duration at 0.050 inch lift of 245 degrees or less because modern lobe ramps are typically much shorter. Maybe a bit dicey for L-88/ZL-1 cams though.
The advantage is having to position the crank at only four places.
Firing on #1, timing mark at TDC adjust Exhaust 4 and 8; and Intake 2 and 7.
Rotate crank 180 degrees, adjust Exhaust 3 and 6; and Intake 1, 8.
Rotate crank 180 degrees (timing mark at TDC, firing on #6), adjust Exhaust 5 and 7; and Intake 3, 4.
Rotate crank 180 degrees, adjust Exhaust 1 and 2; and Intake 5, 6.
This technique should work on most factory SB cams as well because the lobe ramps are similar. It will work perfectly on most modern cams with duration at 0.050 inch lift of 245 degrees or less because modern lobe ramps are typically much shorter. Maybe a bit dicey for L-88/ZL-1 cams though.
The advantage is having to position the crank at only four places.
Team Owner
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Army
Actually with the Duntov 097 you can adjust the cold lash with only two stops on the crankshaft (see attached) which is the way I do it. Now the 30/30 is a different story...don't use this method for that beast.
I have no big nut on the crankshaft pulley to turn the motor over so the less I have to position things the better.
I have no big nut on the crankshaft pulley to turn the motor over so the less I have to position things the better.
