Those of us running bigger cams than CTR in our VTEC motors have probably run into the infamous Lost Motion Assembly failure. Eventually, the piston binds in the LMA cylinder and you get lots of ticking when not in VTEC. This is caused by the VTEC rocker slapping against the VTEC cam lobes when VTEC is not engaged. Then came the introduction of the H22 coil type LMA.
A lot of people used these as a fix not only because they don’t seem to fail, but they are significantly cheaper than the ITR LMAs ($8 a piece compared to $32 a piece). But because they are shorter than the piston type LMAs they needed to be shimmed by a .040" hardened washer, and finding a hardened washer in that size is a difficult task.
Recently Honda just replaced the 2000 Civic SI piston type LMA with a coil type LMA. It is identical to the H22 LMA the only difference is that it has a pressed in .090" thick “seat”.
These are made for B-series VTEC heads. The drawback is because of the added seat Honda raised the price from $8 each to $25 each. OUCH. But to get some solid meaurements I bought a set. And not to my surprise they are exactly the same height as the ITR LMAs.
I just finished installing them in my car and will have a “results” follow up after a test drive. But here are some more comparison pictures.
In for the results. You can hear my b16 valvetrain click-clacking from miles away. I’m sick of explaining to everyone that my valve clearances are fine and it’s the LMAs and it’s “normal” because I’m too cheap/lazy to fix 'em. $200 for an easy fix seems like a good deal.
Turning the car over last night by hand the top end seemed really stiff, but I’m guessing that’s the new Omni Springs that I had installed (they are 10% stiffer than my previous springs). Visually looking at the LMA coils at full lift, they are not fully compressed, but they are getting close. I’m not so sure I would run them with a Spec C or Stage III cam (or any really aggressive high lift cams). After verifying that there is no coil bind, I decided it was time to start the car. Purrs like a kitten. The only noise I hear is my forged pistons and a little “normal” valve train noise. It was late so I didn’t road test it. Still had to let it warm up and adjust the timing. But I will be getting to that today. More results to follow.
its all relative, man. a very good friend of mine ran low 11’s (all motor) maybe 6-7 years ago with an 89’ obd0 1st gen b16 head with no issues/failures with the original ol’ school lma. he ran custom hihg lift, long duration cams with a 10k redline. f.y.i., k series uses the narrow style lma’s similar to the original 1st gen lma’s so they cant be that bad. i’ve used s2p1’s-12.5mm lift, jun3’s-12mm lift, monster ramp angle, b.crower2’s=12.xmm lift, bc3+, 11.4mm all with 1st and 2nd gen heads with no issues. see the problem is most heads should be spec’d for clearance, the same way a shortblock does during a re-build. there are simply too many backyard mechanics that lack the experience needed to detect wear/fatigue/stress on vt components. if these duties are left in the hands of those that have the ability, most problems will be avoided. point being, a quailty machinist will check what needs attention. and he will also explain how an lma works, and its actual task at hand…its not under stress during vtec, so…
First off if you are implying I’m some hack of a mechanic, you’re way off base and need to step down.
Secondly, you have no idea what you are talking about. The LMA is under stress under VTEC. Anytime your cams are moving the LMA is being compressed… unless you can somehow figure out how to stop the VTEC cam lobes from rotating while the rest of the cam turns. The LMA’s sole purpose is to keep the VTEC rockers following the VTEC lobes when VTEC is NOT engaged. This provides two things… it keeps wear on the VTEC lobes and rockers down and reduces noise. The only thing you can clearance on the LMA is if you want to do custom machining of the underside of the VTEC rocker. This will give more clearance allowing a higher lift cam without binding the LMA spring. But since the ITR LMAs do do not bind even with high lift Toda Spec C cams, this is not an issue. Would you like me to send you some stock failed B16 LMAs so you can see for yourself? I wonder why the Helms manual mentions to check them for smooth operation when rebuilding the cylinder head. It’s because they are prone to failure. Honda knew it, that’s why they changed it.
Dan, thank you for this info, I’m glad to see there are still some around here willing to add something productive to this board.
In your opinion, at what point is it best to upgrade to the better lma’s? I’m again rebuilding my b17a (stock except for 11:1 compression). I’ll be running the stock cams for sometime. Most likely I’ll upgrade to itr/ctr level cams eventually. And possibly more aggressive in the distant distant future (if ever). I’m now wishing I had gone ahead and gotten slightly stiffer springs and the better lma’s when this head was at the shop, then I wouldn’t have to worry about this when I eventually upgrade to the itr/ctr cams.
And to anyone else reading this post… I’ll vouch for Dan in the above couple posts. I don’t think there is a single more knowledable person on this board. Nor a single person who has single handedly contributed more to this board. He has been around since the beginning, he is one of the pioneers. The fact that you can simply search and find answers to 99% of your G2 questions is due to members like him who originally figured these things out. In the beginning there were no answers to be had by searching, there was just simply no info out there. We had to figure it out empirically. I have no doubt any of the other OG’s will whole-heartedly agree me.
Colin, thanks for the post and vouch. It’s nice to know that the help is appreciated.
As far as your LMAs, I wouldn’t worry about it until yours fail. They are not that difficult to install with the motor in the car (pull intake, pull battery, pull VTEC solenoid, remove cams, remove rocker rail pins, slide rocker rails out).
If you are running old ones and are considering replacing them, without a doubt get the new B-series version from Honda. They are less expensive than the piston type LMAs (although not much… $24 vs. $32) and due to it’s simplicity in design, I don’t see a failure mode other than maybe spring fatigue. Since I haven’t done any spring life testing and don’t plan on it, I can’t answer that for you. Bottom line, the piston type LMAs fail, even with stock cams. I can’t tell you how many B16s I’ve installed for customers with stock cams and have “sticky” LMAs which cause terrible valve clatter.
As far as installing stiffer springs/changing retainers, there’s a sweet tool to do this with your head on ther car and it’s pretty quick once you have the cams out.
Just ordered a set, and just saw the info you posted on H-T as well. Awesome research man, thanks a lot. I’ll be running these with skunk2 stage2 cams and valve springs, so hopefully that will be a helpful data point.
ive been wonder why even after i did my valve lash adjustment, that my vavle train was still extreamly noisy(B17) Im wondering if this could maybe even be my problem:think:
G2Guru- Is there any particlar millage that you think these are starting to fail. obviusy that kind of a trick question, due to different driving habits of different people:shrug:
on a side note, removal of the vavle springs isnt neccisary to change out LMA’s, are they?
very informative post, good thing we still got some of the OG’s out there to help us rookies out:giggle:
I would say anything over 70,000 miles could be suspect. But to be honest, I have seen B16As come in from Japan that had bad LMAs right when I put them in customers cars (supposedly 40,000 miles or less).
No need to remove valve springs to change out LMAs. You will have to remove your rocker arms though since they sit underneath them. On our cars the rocker rails cannot slide out on the cam gear side (through the two hex caps on the side of the cylinder head). So we have to pull them from the other side. One is easily accessed behind the VTEC solenoid, and the other behind a hex cap on the same side about 3" towards the firewall.
Hmm, I’ve got either 155k or 195k on the engine right now (forget which mileage it had on it when it was purchased)… And as I remember the valvetrain definitely could have been quieter. Making me think I should just go ahead and replace the lma’s before I finish the build and drop it back into the car.
I just spent a few minutes and read the Helms manual in regard to removing the rocker shafts and replacing the lma’s. I’ve never taken that stuff apart before so it’s all new to me.
Hmm, decisions, decisions… This recent build has been full of stuff I just can’t make up my mind about New clutch? no new clutch? Aftermarket mounts? stock mounts? new lma’s? reuse old?.. I can run myself around in circles for hours!
If your clutch has good life and didn’t chatter, as well as it was removed properly to avoid warpage, reuse the clutch.
Use stock mounts. For a street driven car, most after market mounts vibrate more than I like.
There’s a simple LMA test. Push down on your LMAs with your finger. If it sticks at all after you let go, the LMA is bad. If it springs up right away (no hesitation). they’ve got some life left. Removing the rockers is quite simple. Just be sure to keep each set together, and remember which set came from which cylinder and which side.
And don’t forget you can always call your friends for advice/help
You’re the best Dan! The clutch feels fine, some chatter occasionally, but that was pretty normal from the get go (Exedy Organic, installed when I first put in my B17). It’s probably got 60-80k on it now and haven’t pulled it so I’m not sure of the actual condition.
The car isn’t a street car anymore, it’s going to be my track car. It will be street legal and streetable, but I don’t see myself driving it much at all, except to the track. My goal right now is to get it track-worthy again. I’m not looking for anything fancy, just want to put my money where it will make the car reliable, safe and fun on the track so I can focus on my driving skills.
My engine is 98% assembled at this point and is back at the folk’s house. In order to press on the lma’s I assume the cams and rockers need to be removed?
This is a bit off topic… but what are your feelings on the ctr n1 crank pulley? I picked one up from Schu awhile ago and was planning on using it. But I was talking with Nino and he mentioned that after all of his problems and after some research he opted to remove his in favor of a stock piece w/ integrated damper.
Colin, you’re not alone. I think it’s an Exedy problem. Mine is chattering like a big dog… driving me crazy. I have had a new ACT HD Pressure plate and Hybrid street disc sitting in my garage since December 2006… and yet it still sits there. I’m getting new axles soon and then going to do the clutch at the same time. When you pull it remove the bolts in steps in the correct pattern. When it’s off you can determine if the hot spots on the flywheel and pressure plate are acceptable or not. If you’re getting chattering, you may just want to replace it if you have the funds as it will only get worse, not better… especially with track driving.
You assume correct. You have to remove the cams and rockers to change LMAs, but it’s really not that much work and easy with the engine out of the car. If I was there I’d help you knock it out.
I agree with Nino. The stock damper helps reduce harmful vibrations to the crankshaft and is there to extend bearing life. Race motors get rebuilt all the time, so they make everything as light as possible (such as knife edging the crankshaft which I would never recommend for street motor).
If you’re only running your alternator, pick up a machined version of the stock crank pulley. Inline Four has them or if you’d like you can send me your stock pulley and I’ll turn it down for you. I did it with my own pulley.
New clutch? no new clutch? Aftermarket mounts? stock mounts? new lma’s? reuse old?.. I can run myself around in circles for hours!