lost motion assemblies

civiclxb16

Senior Member
hey i was talking to one of my boys and he told me that i should look at changing my lost motion assemblies, but he had to go so he didn't explain it to me but i was wondering what exactly is that and what does it do?
 

reckedracing

TTIWWOP
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Yes, a bad lost motion assembly will cause a valvetrain tapping, and causes the valve clearences to go out of spec much more frequently. As for the oil, the added pressure causes a pin to lock and engage the big lobe.

Check the operation of the lost motion assembly by pushing on the mid rocker arm. The lost motion assembly should compress fully and operate smoothly through its full stroke. Replace the assembly if it does not work smoothly.

google search... as to what exactly it does, no idea
 

phunky.buddha

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You really can't tell if you need to change the lost motion assemblies without opening up the head first. Flip up the rocker arms and press on the LMA with your finger. Press it until it bottoms out. It should feel smooth and bounce back up when you release it. If they don't pop right back up or feel "sticky" then you need to replace them.

Some people just soak their LMAs in motor oil for a day or two to loosen them up and throw them right back in, but I've never had that work for me- even after soaking them for over a month.
 

civiclxb16

Senior Member
lol dam a month, ok next weekend i am putting in my cams so i will check it then but i was wondering if my sohc vtec LMA will fit in, since honda wants an arm and a leg for one
 

DelSlo

Senior Member
Originally posted by Calesta@Jan 20 2005, 07:57 PM
You really can't tell if you need to change the lost motion assemblies without opening up the head first. Flip up the rocker arms and press on the LMA with your finger. Press it until it bottoms out. It should feel smooth and bounce back up when you release it. If they don't pop right back up or feel "sticky" then you need to replace them.

Some people just soak their LMAs in motor oil for a day or two to loosen them up and throw them right back in, but I've never had that work for me- even after soaking them for over a month.
[post=448878]Quoted post[/post]​



hmm i geuss kinda like doin lifters? i wonder if you can clean them out and then soak em, dont know if varsol would be adequate.... personally im not the person to take the valvetrain apart and soak em and hope it all works, but when im not doin them and someone asks me whos cheap, ill say to do that! haha thanks calesta! :D
 

civicious

FüK-VTEC
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Originally posted by civiclxb16@Jan 20 2005, 07:08 PM
i was wondering if my sohc vtec LMA will fit in, since honda wants an arm and a leg for one
[post=448884]Quoted post[/post]​


I'm thinking :no:
 

phunky.buddha

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Originally posted by civiclxb16+Jan 20 2005, 07:08 PM-->
lol dam a month, ok next weekend i am putting in my cams so i will check it then but i was wondering if my sohc vtec LMA will fit in, since honda wants an arm and a leg for one
[post=448884]Quoted post[/post]​
Yeah- I just left them in a bowl full of motor oil. It was actually longer than a month- they were there from something like November all the way to when I moved out last August.

Originally posted by DelSlo@Jan 20 2005, 07:09 PM
hmm i geuss kinda like doin lifters? i wonder if you can clean them out and then soak em, dont know if varsol would be adequate.... personally im not the person to take the valvetrain apart and soak em and hope it all works, but when im not doin them and someone asks me whos cheap, ill say to do that! haha thanks calesta! :D
[post=448885]Quoted post[/post]​


I guess it's like doing lifters, but I've never done them so I don't know. :) Cleaning them out and then soaking them might work.

civicious
@Jan 20 2005, 09:45 PM
Go ahead and use SOHC D-series LMA's. Have fun. Be sure and let me know how it turns out.
[post=448935]Quoted post[/post]​


I actually think that they're interchangeable... at least in terms of actually fitting into your head. If they can be swapped, I still don't know what the clearance difference is between the B series and D series LMAs.
 

phunky.buddha

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I dunno. If it fits, it just has to match the B series' LMAs for height and clearance and they'll work. It doesn't matter if there are only 4- you can always buy more.
 

phunky.buddha

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:shrug:

I'd have to look at them up close. I haven't seen a SOHC VTEC head taken apart before- just B and D non-VTEC. :lol:
 
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