What is lifter preload and how can it adversly affect the valvetrain
01-18-2002, 06:15 PM
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What is lifter preload and how can it adversly affect the valvetrain Guys I have done alot of searching on this subject and I'm not too clear on it yet. Here is some background info. I recently installed a thunder 224 224 112lsa cam. I noticed what I would consider alot of valvetrain noise(ticking that is barely audible at idle but is very noticable at higher rpms at part throttle). I have reasearched this and I know that I did not preload the lifters at all and some posts have stated that this could be the cause of all the noise. I have even read how to adjust it by getting the valve to be completly closed and then turn the rocker bolt until the pushrod stops turning and then about 1.5 turns more after that. What I did on the install was just tighten all the rocker bolts in no specific order I just did passenger side then driver side. I first tightened them to 21 ft lbs and then turned the motor over with the starter and re-tightened them to I think it was 25 ft lbs. Is the ticking I hear actually causing damage? How does lifter preload come into this equation? And finally do I need to go back in and tighten the rocker bolts differently in order to attain the proper preload? Any help would be appreciated on this guys as I don't want to break or hurt anything just because of an oversite on my part.
01-18-2002, 06:48 PM
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Re: What is lifter preload and how can it adversly affect the valvetrain You need to get the #1 cylinder to top dead center. If you have the timing cover off, the dots will line up on the sprockets. Since that's the hard way considering everything is back together, pull the valve cover off and have someone "bump" the ignition until you can visibly see that both the intake and exhaust valves are closed. Once the #1 cylinder is at TDC, you need to tighten exhaust valve rocker arm bolts 1, 2, 7, and 8 to 22 lb. ft. of torque. Do the same to intake valve bolts 1, 3, 4, and 5. Rotate the crank 360 degrees, and tighten exhaust valve bolts 3, 4, 5, and 6 and intake valve bolts 2, 6, 7, and 8 to the same 22 lb. ft. of torque. The added valvetrain noise you're hearing are some loose rockers since they weren't tightened in sequence. Be sure that the pushrods are sitting flush on the lifter and rocker arm before tightening down the rocker arm bolts. Give this a try, and let me know how it works. <img src="gr_stretch.gif" border="0">
[ January 18, 2002: Message edited by: Trevor D ]</p>
[ January 18, 2002: Message edited by: Trevor D ]</p>
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01-18-2002, 07:38 PM
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Re: What is lifter preload and how can it adversly affect the valvetrain Thanks trevor so tightening them in the correct pattern does make a difference.
01-18-2002, 09:29 PM
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Re: What is lifter preload and how can it adversly affect the valvetrain You bet it does. I made the mistake once on my T/A right after I got the Crane 1.8:1 roller rockers. People could hear me a block away; I was the guy with the unreal ticking. <img src="gr_grin.gif" border="0">
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01-19-2002, 03:35 PM
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Re: What is lifter preload and how can it adversly affect the valvetrain Trevor I got the noise down considerably, There is still ticking but it is ever so slight,, I am very happy though,, thanks for the input.
01-19-2002, 04:25 PM
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I can shift faster than you.
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Re: What is lifter preload and how can it adversly affect the valvetrain [quote]Originally posted by Weltall:
<strong>Trevor I got the noise down considerably, There is still ticking but it is ever so slight,, I am very happy though,, thanks for the input.</strong><hr></blockquote>
Valvetrain noise is very common with aftermarket cams/valvetrain. If it isn't overly loud, it is nothing to worry about.
<strong>Trevor I got the noise down considerably, There is still ticking but it is ever so slight,, I am very happy though,, thanks for the input.</strong><hr></blockquote>
Valvetrain noise is very common with aftermarket cams/valvetrain. If it isn't overly loud, it is nothing to worry about.
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01-19-2002, 04:44 PM
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Re: What is lifter preload and how can it adversly affect the valvetrain LOL vince I was waiting to see you to hear if your car sounds anything like mine,, I think I finally have everything under control I hope,, only time will tell.
01-19-2002, 05:07 PM
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Re: What is lifter preload and how can it adversly affect the valvetrain I emailed you Mike.. Working tonight.? I am laying the smack down on our co-worker Vince.. He claims his car shifts a little higher now and has not given him any problems lately.. I will find out tonight. Even with my car not up to par I should have no problem beating his H/C car with the 4.10's...
06-08-2004, 02:36 AM
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Hey Fellas, I know this is an old thread, but after changing valve springs (stock ones bad - comp blue stripe 918) on my stock engine, LS1 2002 (Australia), it now ticks its *** off. It did have minor ticking before but now is very noticeable with revs etc etc. When we changed springs we did one bank at a time, drivers side then passenger side. I watched him torque each side up to specs (excuse my ignorance but, whatever they are), would the ticking be because they werent done in proper order???
