https://honda-tech.com/forums/showth...MA+replacement

So i read that thread about replacing them. Now that is on a B-series motor in that thread, I have a JDM h22a. I just had machine work done, head is 100% good to go, however i am still curious if the h22's can run the newer spring style LMA's. Is this possible or is that only avaliable for B series? I was also wondering what the benefits are of running the new style spring LMA's vs the old solid cylinder types.

 

You can definitely run the new 96-01 H22A LMA in your head. They simply work better for longer. Not sure if they generate more force than the old style LMA but they do feel really nice and stiff once installed. Can recommend them! Just make sure that you order the P5M LMA's not the P13 ones for the H22A.

 

The new lma's were introduced in 99, but regardless of what you order, the part has been superceded so you'll get the revised design. Their advantage is that they're simply more reliable.

 

Good to hear. Curious how you would ever tell that your lma's are on their way out? Like i said, mine were inspected and came back great, but in the future i am just curious how i would know they are on their last leg.

 

The obvious sign will be that the valvetrain becomes really noisy like you need to do a valve adjustment badly. I'd replace them if the head is out of the car now.

 

Really, hmmm my daily driver 4th gen sounds exactly like that. Constantly sounds noisy even after a valve adjustment.

As for the current head for my project car, the machine shop said it is in great shape. Next year i'll be tearing it apart again so at that point i'll replace them. For now, i have spent to much money

 

NSX ones are better as they have exactly the same height as old style LMA.
part no: 14820-PCB-305

 

Interesting part code. PCB is the p/n code for the F20b iirc, which uses basically what's a H22 head with smaller valves afaik.

Still, makes no sense to use NSX lma's. Prelude lma is $8 v. $22 for NSX.

 

Yeah, I'm aware of that. For $14/each I'm buying the peace of mind that everything is in spec. I did new prelude lmas+shim a few times but I didn't like it.

Also notice a bling factor: 'I got some NSX **** in my head, yo!'

 

I have been able to test them but that is partly due to knowing that ill be replacing them. I pressed down the rocker shafts with a flat screw driver (it has a little lip). If it is really easy to depress the whole assemble (primary and secondary) then you know the LMA's are going. New LMA are so still that I can barely depress them by hand!

Oh yea, my 97 p5m head had the new spring style LMA's in it so I guess it depends where you are as to when you got them. I believe they appeared, at the latest, in 1997 in Jdm p5m heads.

 

There's no shimming involved when you use the new H22 lma's..in an H22 head. That's only something that B series owners had to do before Honda release what are basically H22 units with the shims installed from the factory for their heads.

 

So how can you explain the difference in height? I have just pulled the old style LMA from the head and compared it to the new style LMA from prelude. 1mm of difference... With 305 LMA none.

 

I think you're the first to have reported any difference in height between the two Prelude lma's, or the need for shimming. Maybe Pirate can shed some like on this.

 

Am I? I have some pictures proving that.

 

I dunno about the difference in height off the top of my head. I think that the '98 style is shorter but the H22A4 heads that use them have shallower pockets. I can measure them tonight and report back later.

Either way, if you're upgrading then it's easy to just set them side by side and see.

 

new prelude lma

nsx lma 305

old style lma (it's ITR one but H22 is the same)

 

Yeah, I dug out the H22 LMAs and yeah. ^^What Pentaq said. The '98+ prelude ones are about .090" short and will require shims.

 

so, what about 97 H22A4 ones?this topic has been one thats been bugging me for a few years now. I don't need em yet, but I would like to know for sure what to do when the time comes.

 

check the part number. if it's PCB-003 then they're too short and need a shim

 

Another thing is to use OBD2 GSR/ITR LMAs. They are a single spring design (unlike the early H22 kind) and are less likely to tick and are a direct replacement. No shims required.

 

What is the part number for those?

 

Pirate are you talking about the 'new' B-series lma's with the shims preinstalled from Honda? Iirc, the B16 lma's are the cheapest out of all the part numbers.

I find it rather odd that Honda took the H22 part and adapted it to B-series, but forgot that there was a install height variance within the H22 model itself (pre-98 v. 98+).

Prudz, just look in the Bernardi parts catalog. These are all superceded parts, so you're only going to find one p/n for any given model.

 

I was talking about used GSR LMAs, but if ALL the new LMAs are one part number then hey, that's what you get.

 

I just went through the parts catalog and looks like they've all got one part number now. This the new one:

B16/B18c1/NSX: 14820-PCB-305 $23.27

ITR lma doesn't have the superceded p/n listed, wonder if they got switched or not.

 

this is the most confusing thing about the H22 IMO.what is the best type of washer to use for a shim if it is needed?Thanks for all the help everyone(pentaq,vinuneuro,Pirate) in this thread.