OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

Yes, I finally have taken the time to do my Honda B-Series Lost Motion Assembly Comparison Test. This thread is not to start a fight or to upset people; I am merely stating my findings with my ProForm Spring Tester. I am fully aware everyone has their favorite brand for one reason or another and I tried to be as unbiased as possible. There are positives and negatives to all of the LMAs and your specific situation may vary. IF you see a discrepancy or disagree with my testing, then I highly suggest that you purchase all the parts and do it yourself. I did not do hardness testing since it appears most people don't care about this so I did not waste my time doing it. This is for reference only, what you get from it is up to you. I know, enough with the banter already, let's get to it!



HONDA B-SERIES LMA TEST

Part Numbers used for Testing:

Honda = 14820 - PCB - 305
Skunk2 = 312 - 05 - 0200
ScienceOfSpeed = ENPP - 662

The Honda LMAs have top and bottom shims that are both highly magnetic. They appear to be made of the same material. The shims are very tight fitting both top and bottom. Upon coil bind, the stack stays uniform throughout.

The Skunk2 LMAs have only a top shim. It is only moderately magnetic. The top shim fits moderately, minimal force was required for removal. Upon coil bind, the coils start to spring outwards what could be considered a decent amount.

The SOS LMAs have a top and bottom shim. The top is highly magnetic and the bottom is not magnetic at all. It appears to be made of aluminum and scratches easily. The shims are very tight fitting both top and bottom. Upon coil bind, the coils start to spring outwards slightly, but very minimal.

(Hardness testing would have had more details for confirmation. :P)

Feel free to save my chart. Open to suggestions via PM. Enjoy!!!

I do sincerely apologize for the random order of the springs in the pictures. The top 3 pictures are SOS Left, Honda Center, and Skunk2 Right. The botom 5 pictures are Honda Left, Skunk2 Center, and SOS Right.

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

Good Information! Thank you for testing and Sharing!
Interesting how the S2 LMA didn't return to their full height after compression.

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

looks like the OEM has larger top and basis shim than the others. Did you ever get a chance to measure them at all that way?

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

Thanks CRV, I know a lot of people been waiting for this test. Really interesting with the difference in shim design and varying strengths of magnetism.

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

You know, that never even crossed my mind. I will try and measure all that this week and update the chart with that information as well. Looking back, I should have taken the pressures to 100 lbs while I was at it. May do that since I will have to get everything back out. Thanks for the idea!

You are welcome everyone! Took a few hours all in all. ;)

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

Sticky worthy?? (hint hint)

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

I'll second that^^^ It might help reduce common threads asking which ones to use if we keep all the info and inquiries here

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

Thanks for sharing!

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

Updated information again, enjoy!

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

I find it interesting that the Skunk2 LMA has the longest spring due to no bottom spacer but achieves coil-bind the soonest.

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

Not sure 'interesting' is the word I'd use...

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

Sorry if I it seems that way, but actually the SOS binds first, then OEM, and then the Skunk2. If you look at my chart it shows the Skunk2 actually compresses the most. You can see in my "coil bind" picture that the Skunk2 isn't fully compressed.

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

Looks like skunk2 are for big high lift cams?

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

As stated previously, I am trying to be as unbiased as possible. :)

If you have agressive cams, do you use soft springs or stiff springs? Technically yes, the compression is more on the Skunk2 springs, but there is less tension on the rocker at all times for the same amount of lift. If you look at the chart, to achieve the same seat pressure, Skunk2 requires more compression than the other two LMAs meaning it is a softer spring.

Reading the charts they are progressive spring rates. The event that inspired this test was a I kept getting phantom knock at around 5.5 - 6k on the low cam. My VTEC was set to engage at around 5.8k on my Skunk2 Pro2+ cams. I was running Skunk2 LMAs at the time as well as S2 Pro Springs, Retainers, Valves, and Cam gears. After many hours of checking and changing things I decided to swap out the LMAs as I was occasionally getting a random click depending on exact idle RPM. I put in the OEM ones, and the problem vanished without touching a single thing other than pulling the valve cover.

Given, that was over a year ago... but hey, I have quite a few write-ups on the shelf waiting to be put together, some have been there too log though and are obsolete. This was by far the quickest and easiest one and still took me a few hours. Oh well. :)

I just want to say I am not bashing any company and had no clue what the results would be. I am very inquisitive by nature, so it was only natural I wanted to get the the bottom of the problem I was having. Everyone has their personal preferences, but I prefer to base my decisions off of facts. ;) :thumbup:

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

You SIR HAVE BEEN STICKIED!!!! great job

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

Why thank you, very much obliged!

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

Great info!

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

really nice test

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

Awesome info thx

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

So is the free height after mean that the S2 lma did not rebound it's full height after being compressed? When all the others did :( straight out of the package with one push they lost .014? Of lift?

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

The SOS will coil bind the soonest and they are the stiffest?
Think I'm just gonna replace mine with OEM H22 spring type lmas I did use my old lmas with 142k and then rebuilt everything with pro1's most deff. Something is wrong because they were never this loud. My stock lmas did not have any bottom shim tho at all for h22 is this right?

Re: OEM vs Skunk2 vs SOS B-Series LMA Comparison Test
 

great write up!

planning on running some skunk2 pro 2+ cams...should i stick with OEM or go with Skunk2 LMAs?