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11-07-2013, 01:16 PM | #1 |
Building Dreams out of Dimes!
Join Date: May 2005
Location: Bonham, Tx
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Roller Rockers extremely loose after engine rebuild. Is this normal?
Hey, I was wondering if it was normal to have to go back and readjust your rockers a few times after a new engine build. I broke in the engine, started it a few times to set timing and check for leaks, and drove it about 1/4 of a mile to check everything.
I heard my roller rockers chattering so I pulled the valve covers and man about 3 of them were extremely loose. I have flat hydraulic lifters and roller tip rockers. I also set initial valve lash before first engine break in. Now I feel I should go back through the entire valve lash Process again. Is this normal when running roller tip rockers and flat hydraulic lifters after a fresh rebuild? Thanks!
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1981 Chevy short/wide. SB400 350th |
11-07-2013, 02:18 PM | #2 |
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Re: Roller Rockers extremely loose after engine rebuild. Is this normal?
I NEVER trust initial lash to be quite right. Once the engine has been broke in I go back and do a running lash. If you haven't already done so new rocker nuts are a good idea. They do wear out.
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11-07-2013, 05:12 PM | #3 |
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Re: Roller Rockers extremely loose after engine rebuild. Is this normal?
Normal
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11-07-2013, 08:23 PM | #4 |
Building Dreams out of Dimes!
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Location: Bonham, Tx
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Re: Roller Rockers extremely loose after engine rebuild. Is this normal?
I guess I'm going to go ahead and dice up my valve covers so I can do a running valve lash adjustment. Seems like thats the norm for hydraulic lifters. I have always had solid lifters so this kind of new to me.
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1981 Chevy short/wide. SB400 350th |
11-07-2013, 08:34 PM | #5 |
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Location: Louisiana
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Re: Roller Rockers extremely loose after engine rebuild. Is this normal?
I always set them cold on the motor stand, put the covers on and forget about it. Never had to redo them.
They were either not set right to begin with, studs pulling, nuts backing off, or cam going flat. |
11-07-2013, 11:04 PM | #6 | |
Dino burner
Join Date: Nov 2002
Location: Calgary, Alberta, Canada
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Re: Roller Rockers extremely loose after engine rebuild. Is this normal?
Quote:
I've never found it necessary to do spray the engine and fenders and the garage wall and the dog with hot oil doing a running lash check. I trust the accuracy of feeler gauges and dial indicators far more than my hearing the tick-tick-tick of a running engine. |
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11-16-2013, 07:45 AM | #7 | |
Building Dreams out of Dimes!
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Re: Roller Rockers extremely loose after engine rebuild. Is this normal?
Quote:
Also, I dont see how oil is going to splash everywhere as long as you have a "cut" valve cover.....?
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1981 Chevy short/wide. SB400 350th Last edited by Hazieview; 11-16-2013 at 07:51 AM. |
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11-16-2013, 08:48 AM | #8 |
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Re: Roller Rockers extremely loose after engine rebuild. Is this normal?
You don't have to hack up a valve cover to set the valves on a running engine. At idle its not going to spray everywhere, the worst that's going to happen is that it will DRIP onto your wires and exhaust manifolds/headers and smoke. Everybody has a different way of setting lash, I set the lash on a new cam during break in a little on the loose side, then do a running lash, but that's just me. Some people set lash one full turn on a running lash, I only do a half turn on a running lash... once again just me. Its hard to screw up, unless you really crank down on it. I believe using feeler gauges and dial indicators is more precise, I used to set up my turbo diesels in the military that way. I'm just too lazy to do it on my SBC.
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Welcome to my build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=574370 Last edited by Jabes1; 11-16-2013 at 08:49 AM. Reason: . |
11-16-2013, 09:01 AM | #9 | |
Building Dreams out of Dimes!
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Re: Roller Rockers extremely loose after engine rebuild. Is this normal?
Quote:
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1981 Chevy short/wide. SB400 350th |
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11-16-2013, 11:25 AM | #10 |
Just here to tinker
Join Date: Jun 2008
Location: Holland, MI
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Re: Roller Rockers extremely loose after engine rebuild. Is this normal?
Any brand new engine should be pre-lubed by a drill using and old distributor shaft. Those first few seconds of an engines life are the most important. And, naturally, if you've pre-lubed the engine properly, that means the hydraulic lifters are now pumped up with oil. Now go through and set your valve lash to zero and then go no more than 1/2 turn. 1/8 turn if the engine constantly sees high RPM's (like Marine engines). 1 full turn is too tight and will burn valves and destroy camshafts. Also, if you are breaking in a new cam I hope you poured in the zinc additive or there is a good chance you can kiss that cam goodbye.
And I have found that this procedure for adjusting valves is far less confusing to follow and works on every single engine: When exhaust valve starts to open, SET INTAKE on same cylinder When intake valve starts to close, SET EXHAUST on same cylinder Works every time and I have never had to go back and re-adjust my valves on a new engine.
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11-19-2013, 08:47 AM | #11 |
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Re: Roller Rockers extremely loose after engine rebuild. Is this normal?
And no feeler gauge is needed..unless you running a solid roller cam..
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1981 C-10 (Pop's) 1978 Camaro 2006 Lacrosse |
11-19-2013, 09:05 AM | #12 |
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Re: Roller Rockers extremely loose after engine rebuild. Is this normal?
Forget the "spinning" the pushrod method, they'll spin even with the lifter on the lobe if there's a perfect fit between the pushrod and lifter and rocker. Rattle it up and down to feel the movement, zero is when you can't rattle any more, then go 1/2 or 3/4 turn down from there. If the nuts are backing off (mark some with yellow machinist's marker, recheck after a few miles), replace 'em.
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11-27-2013, 03:55 PM | #13 |
Building Dreams out of Dimes!
Join Date: May 2005
Location: Bonham, Tx
Posts: 892
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Re: Roller Rockers extremely loose after engine rebuild. Is this normal?
I think I found the problem... My 'rocker adjustment nuts' are not long enough. I should of noticed this when I put them on but I guess I didn't.
When I go to put the socket on the adjustment nut , to tighten it, the bottom of the socket hits the rocker. I can't get a good 'bite' on the adjustment nut. So I either need a longer adjustment nut or wider roller tip rockers so I can actually fit a socket on the nut. Do they make 'adjustment nuts that are longer or would you recommend getting different roller tip rockers? I can not do the running valve adjustment unless I have longer 'adjustment nuts' or a rocker wide enough that it actually allows me to fit the socket on the nut. I cut the valve cover and started the motor. I actually watched one of the adjustment nuts start backing up. On another rocker the set screw almost backed all the way out. Thanks! (p.s. All proper break in methods were used. I prelubed the engine with an old toothless distributor, I used zddp in the oil, etc. etc.)
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1981 Chevy short/wide. SB400 350th Last edited by Hazieview; 11-27-2013 at 04:17 PM. |
11-27-2013, 06:39 PM | #14 |
Building Dreams out of Dimes!
Join Date: May 2005
Location: Bonham, Tx
Posts: 892
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Re: Roller Rockers extremely loose after engine rebuild. Is this normal?
I ended up just buying a new set of Comp Cam poly locks that were 1.30" long. The ones I have now are only 1.0" long so that will give me more that a quarter inch of room for a socket. Hope they work!
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1981 Chevy short/wide. SB400 350th |
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