C1 & C2 Corvettes General C1 Corvette & C2 Corvette Discussion, Technical Info, Performance Upgrades, Project Builds, Restorations

Adjusting valve lash - Solid lifter

Thread Tools
 
Search this Thread
 
Old 12-30-2009, 12:00 PM
  #1  
Glasshole
Burning Brakes
Thread Starter
 
Glasshole's Avatar
 
Member Since: Jan 2009
Location: Delta BC
Posts: 922
Likes: 0
Received 2 Likes on 2 Posts
Default 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
Old 12-30-2009, 12:42 PM
  #2  
1snake
Le Mans Master
 
1snake's Avatar
 
Member Since: Dec 2007
Location: Puget Sound
Posts: 8,000
Received 652 Likes on 446 Posts

Default

http://www.lbfun.com/warehouse/tech_...n/SBvlvadj.pdf

Jim
Old 12-30-2009, 12:52 PM
  #3  
65-396
Instructor
 
65-396's Avatar
 
Member Since: Dec 2007
Location: Denver Colorado
Posts: 179
Received 6 Likes on 5 Posts

Default

Just curious, is this the same proceedure for big blocks?
Old 12-30-2009, 01:38 PM
  #4  
GCD1962
Race Director
 
GCD1962's Avatar
 
Member Since: Feb 2004
Location: CT
Posts: 14,758
Received 161 Likes on 122 Posts

Default

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.

Last edited by GCD1962; 12-30-2009 at 08:03 PM.
Old 12-30-2009, 01:41 PM
  #5  
MikeM
Team Owner
 
MikeM's Avatar
 
Member Since: Mar 2003
Location: Greenville, Indiana
Posts: 26,118
Received 1,843 Likes on 1,398 Posts

Default

Originally Posted by Gl*******
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.

Bob

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.
Old 12-30-2009, 04:15 PM
  #6  
Sxrxrnr
Pro
Support Corvetteforum!
 
Sxrxrnr's Avatar
 
Member Since: Nov 2009
Location: Milpitas Calyfornua
Posts: 667
Received 6 Likes on 6 Posts

Default

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
Old 12-30-2009, 04:39 PM
  #7  
427Hotrod
Race Director
 
427Hotrod's Avatar
 
Member Since: Jan 2000
Location: Corsicana, Tx
Posts: 12,603
Received 1,874 Likes on 912 Posts
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist

Default

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
Old 12-30-2009, 05:35 PM
  #8  
Ironcross
Race Director
 
Ironcross's Avatar
 
Member Since: Nov 2002
Location: Taylor Michigan
Posts: 12,142
Received 40 Likes on 36 Posts

Default

Originally Posted by Gl*******
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.

Bob
the best way.......the others are too complicated and take too long....


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; 12-30-2009 at 05:38 PM.
Old 12-30-2009, 05:59 PM
  #9  
Frankie the Fink
Team Owner

 
Frankie the Fink's Avatar
 
Member Since: Aug 2007
Posts: 58,062
Received 7,082 Likes on 4,736 Posts
Army

Default

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...
Old 12-30-2009, 07:01 PM
  #10  
Secret Squirrel
Drifting
Support Corvetteforum!
 
Secret Squirrel's Avatar
 
Member Since: Jul 2000
Location: Melbourne Australia
Posts: 1,347
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by Gl*******
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
I have always used method 1. as well

But.........In method 1. your exhaust is set when the intake is nearly closed, not beginning to close as you stated

cheers
Jim
Old 12-30-2009, 07:23 PM
  #11  
midyearvette
Le Mans Master
Support Corvetteforum!
 
midyearvette's Avatar
 
Member Since: Nov 2008
Location: columbus oh
Posts: 5,691
Likes: 0
Received 11 Likes on 11 Posts
Default

Originally Posted by 427Hotrod
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
..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......
Old 12-30-2009, 07:55 PM
  #12  
Avispa
Safety Car
 
Avispa's Avatar
 
Member Since: Mar 2009
Location: Oldsmar, FL
Posts: 4,062
Received 884 Likes on 633 Posts

Default

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.
Old 12-30-2009, 07:59 PM
  #13  
Frankie the Fink
Team Owner

 
Frankie the Fink's Avatar
 
Member Since: Aug 2007
Posts: 58,062
Received 7,082 Likes on 4,736 Posts
Army

Default

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.
Attached Files
File Type: doc
Valve_Lash.doc (1.24 MB, 430 views)

Get notified of new replies

To Adjusting valve lash - Solid lifter




Quick Reply: Adjusting valve lash - Solid lifter



All times are GMT -4. The time now is 02:14 PM.