Been scanning the archieves the past few days about the type s pistons. I am lost on what is actually correct.

Does anyone sell actual type s pistons a/b? I haveonly found Oversized or just standard(what is standard anyways?). Does not mention anything about a/b. I am assuming it is very very hard to find the right sized type s piston to work with my motor? (I'm looking for B type s pistons) I'm assuming that no one finds the right pistons, they just go ahead and hone the cylinders .25 and throw in the oversized type s pistons?(i would rather not have to have my block honed... I won't be able to afford a large chunk of downtime)

Brings me to another question, I read that after 50k miles the cylinder walls need to be rehoned. I currently have 117k miles on my motor, what kind of effect would this have of the reliablity of my set-up if I did NOT hone the cylinder before replacing the pistons? Like i said before, it all comes down to how much time I have.

-Matt

 

personally i would never put in new pistons and rings w/o honing, gonna run the risk of the new rings not seating, and well thats just gonna suck. i would strongly suggest you get the os pistons and just go ahead and hone it out and do the whole block work right the first time. dont half *** it

 

Can we PLEASE put something on the type S pistons in the FAQ? These threads constantly pop up... There have been a few good ones, just link them into the links thread.

anyway, if you are not going to re-hone, I would re-use the rings off the current pistons. When you take it apart, carefully note each ring's position, and reinstall them with the new pistons in their original locations. Also, A and B piston sizes are nearly the same. You can probably use either and still be within spec. Just measure things and check the helm manual. If you get oversize, re-hone the block and get new *oversize* rings from honda.

 

Ya, what the others have said here. Get the job done right and complete the first time. It's not all that expensive to have a machine shop do the honing, just be sure to give them the EXACT directions for honing the FRM liners, there is a different procedure, and different grit stone to use vs. steel liners, which is what most shops are used to. If you search for this, you'll find it on this site, I think it was 96SR-V that posted it last year or the year before directly from the HELMS manual.

With 117k, if your replacing pistons, get the .25 over sized, and have that block honed, and use new rings as well.

Another thing to consider is what year is your motor? Type-S pistons require one of two rod pins, newer H22A's (97 up) have the correct pin, 93-96 have the other type. (Sorry, I forget them now, but there are two types of pins for connecting rod to piston). If you have an older H22A, and your putting in Type-S pistons, you need newer rods, or have your old ones machined. I went with the new ones, others have machined. My preference is to do it right, and get the new ones.

 

I agree with getting a Type S piston thread started and archived, thats a definite IMO...

Ive been trying to find specs on Type S pistons forever...

CC Volume of the dome = ???
Compression height = (finally got that 1.222)


Im sure there are sever other questions regarding as well...

Ive seen so many unacurate compression guestimates on this forum and others with H23/VTEC's using Type S pistons... I want to be able to calculate the actual compression numbers with all possible H block/head combinations but with out key factors such as the cc volume of the dome I can only make an educated guess...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 94vtecmn &raquo;</TD></TR><TR><TD CLASS="quote">
there are two types of pins for connecting rod to piston). If you have an older H22A, and your putting in Type-S pistons, you need newer rods, or have your old ones machined. </TD></TR></TABLE>

97 and up h22s have full floating wrist pins like the Type-S, if you have 93-96 you have a pressed in wrist pin. If you have your rods machined to utilize a slightly larger wrist pin, there should be no negative effects, your best bet is to do which over one you can get done for cheaper

 

http://www.importselect.com/ has both A and B sized pistons, just email them how many you need. good prices and great service.

 

what is the difference between the A and B pistons?

also, do you need to do any head modifications with .25 oversize pistons?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by iakona &raquo;</TD></TR><TR><TD CLASS="quote">what is the difference between the A and B pistons?</TD></TR></TABLE>


Size.
A 86.990- 87.003
B 86.980- 86.993

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by iakona &raquo;</TD></TR><TR><TD CLASS="quote">
also, do you need to do any head modifications with .25 oversize pistons?</TD></TR></TABLE>

Rather not.

 

Although you could probably just swap the rings and that would work, I would prefer not.

I do no believe that honing is necessary on these motors. I would only hone it out if it needed to run the OS piston.

I also do not believe that running a/b pistons is necessary. If in doubt, run the A's for the slight increase in clearance.

 

so the stock TypeS pistons are the B types?

and thanks for the info!

 

hmm when inspecting used rings (lets say my motor) how could I tell if they are still good? Will a leakdown test give me an accurate idea on how the rings are doing, or will a visual inspection give better results?

 

Guys add as much type-s piston info here and I'll add it to the FAQ

 

Here's a question I'd like to see answered. Can the stock ECU handle the the slightly larger pistons and higher compression?

 

id like to know how to identify the A from the B all i can see is p5p JO

Also when changing h22a4 pistons with the type s pistons, do you hone or not. some say you have too, some say you have to sleeve, somthing about a coding that honeing will remove.

 

http://cgi.ebay.com/ebaymotors...d=1,1

 

the guy i just bought the pistons from told me this, for the sake of this thread

"Hey, I'm glad you are happy with the pistons. As far as the rings they
are factory Honda rings. The pistons aren't an A or B. The A and B thing
really only applies to the origional factory installed pistons. When you order
OEM replacements like theese or any others, they do not specify "A" or "B".
Since you are honing the cylinders it won't matter anymore anyway so
you can put them in any cylinder you like. Also I included bearings with the
rods, make sure they are the same color as the ones you are pulling out, if
they are not, don't use them as your clearances will be incorrect. Just a
word of advice when honing your engine. Honda is very specific about honing
theese engines because they use fiber reinforced cylinders or FRM as it is
sometimes called. You should only use a rigid hone with a stone of 600 grit
or higher, also you can only hone for twenty revolutions and every five
you need to pull out the hone and clean the stones and the cylinders. Never
use a ball hone. If you do not follow this procedure your rings will not
seat properly and your engine will burn oil like nobodys business. We don't
mess with the internals of theese motors at the dealer much anymore because
many of the techs would hone the engine improperly just because they didn't
know any better and it would burn oil and smoke like crazy. Then the
customer would be pissed and we would have to tear the engine down again to fix
it. It is a good design and is still being used in the F20C and F22C in the
S2000s, they just needs special care when working with the internals.
The factory service manual is a great resource when building one of theese
motors. Let me know how it turns out."
Matt

 

dumb question.... if my block has about 30k miles since last hone and is alrdy OS... can I just slap in type s pistons with new rings if the walls look good?

 

i didnt hone mine. just match the pistons to the bore and use fresh honda rings
you only need to hone the cylinders if the walls are out of round or their are deep grooves. just throw them in

 

i read the thread about the type s pistons in the h22 n how if its an a1 u need to change the rods or modify them n if its an a4 u should be ok bc it has the same rods with floating pin. wuts the deal with an h22a? is it the same? pre 96-97 u gotta change n after its ok?