Valve adjustment help-solid lifter
#1
Valve adjustment help-solid lifter
I recently installed roller tips on my 71LT-1. Following the instructions from the chassis manual, I rotated the engine manually and adjusted the intakes and exhuast in sequence using a feeler gauge (.024" intake, .030" exhaust). Now, it is my understanding that I need to normalize the engine temperature and re-adjust the valves again as the clearances change due to thermal expansion. My question is this; while the engine is running do I simply place the feeler gauge between the rocker and spring and adjust so that the feeler gauge just fits or is the adjustment similar to hydraulics where the rocker is adjusted down to zero lash (no rattle)?? Any comments would be appreciated.
#2
Re: Valve adjustment help-solid lifter (mulchie)
My question is this; while the engine is running do I simply place the feeler gauge between the rocker and spring and adjust so that the feeler gauge just fits or is the adjustment similar to hydraulics where the rocker is adjusted down to zero lash (no rattle)?? Any comments would be appreciated.
#3
Racer
Member Since: Feb 2002
Location: Arlington Texas
Posts: 276
Likes: 0
Received 0 Likes
on
0 Posts
Re: Valve adjustment help-solid lifter (mulchie)
Check with the manufacrurer of the rockers. They should recommend adjusting the clearances either hot or cold. I wouldn't think you would need to do it twice.
But then agin I've never adjusted roller rockers!
But then agin I've never adjusted roller rockers!
I recently installed roller tips on my 71LT-1. Following the instructions from the chassis manual, I rotated the engine manually and adjusted the intakes and exhuast in sequence using a feeler gauge (.024" intake, .030" exhaust). Now, it is my understanding that I need to normalize the engine temperature and re-adjust the valves again as the clearances change due to thermal expansion. My question is this; while the engine is running do I simply place the feeler gauge between the rocker and spring and adjust so that the feeler gauge just fits or is the adjustment similar to hydraulics where the rocker is adjusted down to zero lash (no rattle)?? Any comments would be appreciated.
#4
Le Mans Master
Member Since: Mar 1999
Location: delmont pa
Posts: 6,744
Likes: 0
Received 1 Like
on
1 Post
Cruise-In I Veteran
Cruise-In II Veteran
Re: Valve adjustment help-solid lifter (Kingt)
iron heads and iron blocks the setting will change little or not at all. alum heads and iron block clearance will grow about .004,and alum heads and alum block clearance will grow .010 when hot. also any rocker arm that used a poly lock system should be adjusted .002/.003 loose,tighten the lock nut and then tighten down the rest of the way by just turning the adjustment nut. this will lock the poly lock tight. the top of the studs should also be machined flat if you are using stock chevy studs. :chevy
[Modified by clem zahrobsky, 12:21 PM 3/20/2002]
[Modified by clem zahrobsky, 12:21 PM 3/20/2002]
#6
Safety Car
Re: Valve adjustment help-solid lifter (Kingt)
Solids are supposed to be adjusted hot. With mine I get the engine up to running temp and then take off the valve cover on one side, with the engine off, do the valves one the one side then put the valve cover back on, get it back up to temp and do the other side.
You can do them with the engine running but it makes a mess.
Do a search and you will see some good info on this subject fro the not too distant past.
You can do them with the engine running but it makes a mess.
Do a search and you will see some good info on this subject fro the not too distant past.
#7
Re: Valve adjustment help-solid lifter (69 N.O.X. RATT)
If I do it with a hot engine (not running) this means that I must find TDC (#1 firing position) again and rotate manually to adjust the valves in proper sequence. Seems like a lot more work than is required?
#8
Race Director
Member Since: Nov 2000
Location: Waterloo ontario Canada
Posts: 11,872
Likes: 0
Received 9 Likes
on
9 Posts
Re: Valve adjustment help-solid lifter (mulchie)
I called Comp Cam and asked about adjusting the valves cold and they told me that the setting given on tha cam card was only a ball park figure. If I wanted to change it a little it wouldn't matter. I could tighten up the lash or loosen it if I wanted. I always adjust my valves cold to keep from burning myself and adjust them to card specs and let the hot setting fall where it wants. I would never adjust them twice.
As for turning the motor over in the firing order you can do it by setting TDC, then BDC then TDC and finally BDC. Only 4 half turns adjust certain valves along the way.
As for turning the motor over in the firing order you can do it by setting TDC, then BDC then TDC and finally BDC. Only 4 half turns adjust certain valves along the way.
#9
Re: Valve adjustment help-solid lifter (mulchie)
tsw71, why must the solids be adjusted with the motor off??
#10
Re: Valve adjustment help-solid lifter (mulchie)
Check out this site for info. to all your questions :
http://www.centuryperformance.com/valveadjustment.htm
For mech. lifters, the engine 'must' be off to insure correct lash adj. Why ? - because the lash varies while the engine runs (i.e. valve-in vs. valve-out)
Good luck ! - sounds like a "sweet" engine :cool: :D
http://www.centuryperformance.com/valveadjustment.htm
For mech. lifters, the engine 'must' be off to insure correct lash adj. Why ? - because the lash varies while the engine runs (i.e. valve-in vs. valve-out)
Good luck ! - sounds like a "sweet" engine :cool: :D
#11
Drifting
Member Since: Dec 1999
Location: Reno nevada
Posts: 1,462
Likes: 0
Received 0 Likes
on
0 Posts
Re: Valve adjustment help-solid lifter (mulchie)
mulchie - I have a mech. cam and 1.6 comp cams roller tips. What told you to set them at .024/.030? It's way to wide and it will beat the heck out of your stem tips and rollers. The old 30-30 cams are junk from the past.
IMO - Once you start setting them for the 10th time you will find that cold or hot the values change very little. So I get my motor up to temp and let it cool till it warm to the touch. I'm not going to burn my self or drip oil on hot headers to set the valves. I would just pick a number like .020 feeler gauge. That gives plenty of lash margin and it eliminates the loud bashing you going to have with .030 You don't have to be right on in crank shaft degrees. I bump mine with the starter and it never stops right on. So 10-20 degrees either way doesn't make any difference.
Your low side of the cam is big in number of degrees. So your concern is just adjusting the rockers at the loosest point. You never have to be right on. Which is 20 Degrees + or - on the crank. The best thing to do is invest in Allen Locking nuts and if your need to a stud girdle and then valve adjusment is more of a check because they rarely move.
Big lash numbers like .024-.030 actually make a hot cam less radical at the sacrfice of beating your valve train to death. Low lash numbers like .012 - .018 increase duration and lift of a mechanical cam. My Crane cam card called for something like .014 and .018. It mellowed out and ran better at 20-22.
Guy that have been around solid cams for years don't worry about exactness. My .022 measurement might be measured by another person as + or _ .002 compared to me. Its how much drag you consider right when pulling out the feeler gauge. The real reason that it can't be done on a running motor is: If I place a feeler gauge in place how would you ever be able to determine if your not actually starting to lift the valve off of the seat with everything in motion? If you tighten down the nut and you have a hard time pulling the feeler gauge out your actually starting to compress the valve spring.
IMO - Once you start setting them for the 10th time you will find that cold or hot the values change very little. So I get my motor up to temp and let it cool till it warm to the touch. I'm not going to burn my self or drip oil on hot headers to set the valves. I would just pick a number like .020 feeler gauge. That gives plenty of lash margin and it eliminates the loud bashing you going to have with .030 You don't have to be right on in crank shaft degrees. I bump mine with the starter and it never stops right on. So 10-20 degrees either way doesn't make any difference.
Your low side of the cam is big in number of degrees. So your concern is just adjusting the rockers at the loosest point. You never have to be right on. Which is 20 Degrees + or - on the crank. The best thing to do is invest in Allen Locking nuts and if your need to a stud girdle and then valve adjusment is more of a check because they rarely move.
Big lash numbers like .024-.030 actually make a hot cam less radical at the sacrfice of beating your valve train to death. Low lash numbers like .012 - .018 increase duration and lift of a mechanical cam. My Crane cam card called for something like .014 and .018. It mellowed out and ran better at 20-22.
Guy that have been around solid cams for years don't worry about exactness. My .022 measurement might be measured by another person as + or _ .002 compared to me. Its how much drag you consider right when pulling out the feeler gauge. The real reason that it can't be done on a running motor is: If I place a feeler gauge in place how would you ever be able to determine if your not actually starting to lift the valve off of the seat with everything in motion? If you tighten down the nut and you have a hard time pulling the feeler gauge out your actually starting to compress the valve spring.
#12
Burning Brakes
Member Since: Jan 2000
Location: Columbus, IN USA
Posts: 997
Likes: 0
Received 0 Likes
on
0 Posts
Re: Valve adjustment help-solid lifter (verskel)
I am going through this now. Adjust with engine hot and off. Do the rotation method it works well and does not make a mess like running the engine will.
I have adjusted mine 3 times since my install of the cam. The last time the settings stayed fairly close to true (1000 miles).
And I too have a 71 LT-1 now with a 282S cam.
I have adjusted mine 3 times since my install of the cam. The last time the settings stayed fairly close to true (1000 miles).
And I too have a 71 LT-1 now with a 282S cam.
#13
Burning Brakes
Member Since: Dec 2000
Location: Carlisle PA
Posts: 962
Likes: 0
Received 0 Likes
on
0 Posts
Re: Valve adjustment help-solid lifter (mulchie)
Here's something that you can do... And it's actually not that difficult and takes in the hot/cold setting issue.
1. Get the engine running up to temp.
2. Shut engine down, and set the lash on both the int/exh of one cylinder according to specs on cam card.
3. After the engine is cold, using feeler gauge get the new valve lash settings of the cylinder you had set in step 2. This will show any variance between hot/cold setting.
4. Set the remaining int/exh using the new measurement in step 3.
Presto - alot easier then trying to set them all hot.
[Modified by 70PurpleLS7, 1:39 PM 3/20/2002]
1. Get the engine running up to temp.
2. Shut engine down, and set the lash on both the int/exh of one cylinder according to specs on cam card.
3. After the engine is cold, using feeler gauge get the new valve lash settings of the cylinder you had set in step 2. This will show any variance between hot/cold setting.
4. Set the remaining int/exh using the new measurement in step 3.
Presto - alot easier then trying to set them all hot.
[Modified by 70PurpleLS7, 1:39 PM 3/20/2002]
#14
Re: Valve adjustment help-solid lifter (70PurpleLS7)
I know have some issues on finding TDC. My manual says to find TDC in #1 firing position. Furthermore the chassis manual goes on to state that finding TDC in #1 can be determined by manually rotating the engine. If the #1 valves don't move when approaching TDC then you are in the #1 firing position. Is there a sure fire way to determine TDC in #1 firing position? Where will the distributor rotor be pointing; to #1 or #6. Thanks
#15
Re: Valve adjustment help-solid lifter (mulchie)
I know have some issues on finding TDC. My manual says to find TDC in #1 firing position. Furthermore the chassis manual goes on to state that finding TDC in #1 can be determined by manually rotating the engine. If the #1 valves don't move when approaching TDC then you are in the #1 firing position. Is there a sure fire way to determine TDC in #1 firing position? Where will the distributor rotor be pointing; to #1 or #6. Thanks
#16
Re: Valve adjustment help-solid lifter (tsw71)
Thanks. I originally adjusted them starting from TDC #6 (oops). After TDC in #1 I will be looking for the #1 exhaust valve to begin opening as I rotate the engine again.
#17
Re: Valve adjustment help-solid lifter (mulchie)
After TDC in #1 I will be looking for the #1 exhaust valve to begin opening as I rotate the engine again.
Tom :cheers: