Valve Lashing ?? - Team Camaro Tech
Tech 2000 Our previous General Forum
Replies ONLY - no new topics.

 
LinkBack Thread Tools Display Modes
post #1 of 13 (permalink) Old May 29th, 00, 03:55 AM Thread Starter
Senior Tech
 
Join Date: Jul 1999
Location: Broomfield, Colorado
Posts: 755
I read every engine and Chevy book I have and checked out the old posts on this subject. What I got out of it is that in setting the valves on my SB Chevy w/hydraulic lifters, stock rockers, and aluminum heads - I should tighten the rocker nuts to the point where the pushrods just don't turn plus 1/4 turn up to 1 full turn, depending on who is giving the advice.

The motor only has about 800 miles on it. When I built it I set the valves to tight plus one full turn. It generally ran fine except for a mid-range miss/power loss and a very noisy rocker I discussed in another post. After I located the bad rocker I replaced it and decided to reset the valves while I was at it.

I started with one full turn and the car would hardly run! It sorta burbled/popped back thru the carb and wouldn't idle at all. I reset them at 1/4 extra turn and it runs great but there is a LOT of lifter noise - especially after it gets warmed up. I guess the next step is to go up to 1/2 turn? Any other advice on setting the valves right?



------------------
Scott
'69 400SB, Richmond 5-speed; '99 HD Road King Classic
www.geocities.com/sdenning1
RockyMtnRacer is offline  
Sponsored Links
Advertisement
 
post #2 of 13 (permalink) Old May 29th, 00, 05:17 AM
Senior Tech
Jim
 
Join Date: Apr 2000
Location: York S.C.
Posts: 1,081
The guy that built mine said 1/2 turn once the lash is out of the pushrod. I havent done it yet so........

------------------
67 Camaro SS Conv.
70 Challenger R/T Conv.
ragtopman is offline  
post #3 of 13 (permalink) Old May 29th, 00, 05:18 AM
Gold Lifetime Member
Jody
 
camcojb's Avatar
 
Join Date: Jan 2000
Location: Wilton, Ca. USA
Posts: 10,077
I generally set them at 1/2 turn down. 1/4 turn is noisier but not VERY noisy. Are you sure you're getting the lifter on the right part of the lobe before adjusting?

I like the exhaust opening/intake closing method. Turn the engine over starting at whichever cylinder you choose (I usually start at #1); turn it until the exhaust just starts to open. Adjust the intake rocker. Slowly tighten the rocker until the pushrod doesn't spin or as I prefer lift up on the rear of the rocker arm (spring side) up and down until there is no clearance. Turn the nut 1/2 turn more. Then turn the engine over until the intake fully opens and just STARTS to close (don't close it completely, stop when you see the rocker dropping). Now adjust the exhaust rocker. This method will work with all cams and guarantees the lifters are on the base of the camshaft. I have helped several friends adjust their noisy lifters; it's always been due to improper adjustment (barring a mechanical problem.

Good luck!!!

Jody
camcojb is offline  
 
post #4 of 13 (permalink) Old May 29th, 00, 07:44 AM
Senior Tech
AL
 
Join Date: Apr 2000
Location: Huntington Beach
Posts: 120
I have always adjusted hydraulics with the engine running. Cut the top off an old valve cover and get some rocker clips, this will prevent oil from getting all over. Back off the lash nut until it starts to make noise, then slowly tighten until it stops making noise plus 1/4 turn. If you try to adjust them not running, its very hard to tell when you are at 0 lash unless you have the intake manifold off and you can see the top of the lifters. Works for me!
AL.
302XRAM is offline  
post #5 of 13 (permalink) Old May 29th, 00, 07:57 AM Thread Starter
Senior Tech
 
Join Date: Jul 1999
Location: Broomfield, Colorado
Posts: 755
Thanks for the comments!

I'm doing this by the method where I start at TDC #1 and adjust both valves at the same time. Then I rotate the crank 90 degrees and adjust both valves at #8 and so on.

Camcojb - My Comp Cams 274 Extreme Energy cam has 230/236 duration @ .050 with 112 LSA. If I'm adjusting the valves at TDC would I not be on the base circle?

I just finished adjusting them again to 1/2 turn past tight. The car runs better and the valves are less noisy but there still seems to be a lot of clatter.

------------------
Scott
'69 400SB, Richmond 5-speed; '99 HD Road King Classic
www.geocities.com/sdenning1
RockyMtnRacer is offline  
post #6 of 13 (permalink) Old May 29th, 00, 08:57 AM
Gold Lifetime Member
Jody
 
camcojb's Avatar
 
Join Date: Jan 2000
Location: Wilton, Ca. USA
Posts: 10,077
Should be. I just re-adjusted a friends engine who set his that way; they still made noise until I did it my way. You're right though, it should work.

Have you also checked for any clearance issues?; rocker to retainer, pushrod binding in head slot,correct length pushrods, etc.? Just a thought.

Jody
camcojb is offline  
post #7 of 13 (permalink) Old May 29th, 00, 09:23 AM Thread Starter
Senior Tech
 
Join Date: Jul 1999
Location: Broomfield, Colorado
Posts: 755
Jody -

I checked my Comp Cams instructions and they recommend the same method as you. I'm getting ready to re-adjust them this way as soon as things cool down a bit.

I'm pretty sure all the clearances are OK but if this adjustment doesn't do the trick I'll have to go back and double check everything again. Thanks for the assistance.

------------------
Scott
'69 400SB, Richmond 5-speed; '99 HD Road King Classic
www.geocities.com/sdenning1
RockyMtnRacer is offline  
post #8 of 13 (permalink) Old May 29th, 00, 09:48 AM
Senior Tech
 
Join Date: Apr 2000
Location: Whittier, California
Posts: 246
E-O, I-C method is the ONLY way to do it, works for any cam, and any engine. Is the only way to get cam lobe for valve you are setting on dead center of cam base circle.

Only drawback for those in a hurry or just don't care to do it right is this method is for one valve at a time. No problem for those who want it right, though.

When done right, hydraulic cam engines may be set on the engine stand and valve covers bolted on for good, will not need further messy or other non-correct methods to adjust them.

Solid lifter engines also benefit from the E-O, I-C method, same reason.
IgnitionMan is offline  
post #9 of 13 (permalink) Old May 29th, 00, 10:19 AM
Senior Tech
Lonnie
 
Join Date: Mar 2000
Location: Mesa, AZ
Posts: 744
I always adjust the valves the same was as IgnitionMan. Adjusting them together doesn't guarantee they are both on the base circle. I've had 2 different Comp XE cams and I have noticed they "clack" more than other hyd cams. Maybe because of their faster ramp. Sometimes you can still rotate the pushrod even at zero lash, so, go by resistance instead of "can't turn" to get to zero. Cam manufacturers want .030 past zero, which is about 1/2 turn. Excellent cam choice, by the way.

------------------
67 Camaro 410sb 11.63 @117.6
67 Camaro 388 ET-???
website
Lonnie67 is offline  
post #10 of 13 (permalink) Old May 29th, 00, 01:01 PM
Senior Tech
 
Join Date: Nov 1999
Location: Abilene TX, USA
Posts: 394
If you read through the old post you probably saw the trouble I had by following some of the recomendations of setting lash with the engine not running. I have always used the method of setting them close enough but not too much, then get the car running and set them while running. Just back them off until you hear noise then tighten until the noise stops and then one more 1/4 turn. This is the sure fire, no brainer, way of doing it and it worked great for me for the last 20 years. I wasn't until some expert told me to set them to the exact position with the car not running that I got into trouble. This is by no means to say the people who do it correctly with the car not running are wrong. I'm just saying I think the easiest way is with the car running.
RickB1B is offline  
post #11 of 13 (permalink) Old May 29th, 00, 01:13 PM
Senior Tech
AL
 
Join Date: Apr 2000
Location: Huntington Beach
Posts: 120
Thank You RickB1B! You said it best, its almost impossible to do it wrong with the motor running...always worked for me!
AL.
302XRAM is offline  
post #12 of 13 (permalink) Old May 29th, 00, 02:09 PM Thread Starter
Senior Tech
 
Join Date: Jul 1999
Location: Broomfield, Colorado
Posts: 755
I finished doing it the "right way" this time and it did make a big difference. There's still a little lifter noise but it's really minimal and no doubt part of those good old performance motor noises. Enough work for now - I'm going out and drive!

Thanks everyone!

------------------
Scott
'69 400SB, Richmond 5-speed; '99 HD Road King Classic
www.geocities.com/sdenning1
RockyMtnRacer is offline  
post #13 of 13 (permalink) Old May 29th, 00, 08:22 PM
Moderator
David Pozzi
 
davidpozzi's Avatar
 
Join Date: Nov 1999
Location: Central California, USA
Posts: 10,061
I've done it most of the different ways. I use Ignitionman's method, as it works on anything. I've used the pushrod twist method on hydraulics but get it down to zero lash first by rocking the arm. I've seen where you can get it too tight because the pushrod will sometimes still twist when the lifter is compressed beyond zero lash.
If you are doing hyd lifters on a running engine, try backing off until the rocker clicks, then go to zero lash. Do this to ALL the rockers. Then shut off the engine and give all the rockers an additional 1 turn if stock. This way, you have the engine running for a minimum time and don't have to wait for each lifter to self adjust to the new setting before going on.
If you are using anti pump up lifters, they do not go over 1/2 turn from zero, and I used one set of lifters that were set at 1/4 turn.
By the way. Roller rockers make a solid lifter cam much quieter.
David

------------------
The older I get, the faster I was!
davidpozzi is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome