i just finished reading an article about the manufacturing process of the jdm b18c-r.
https://honda-tech.com/zerothread?id=501863

basically it says that all the parts were designed to be used in perfect harmony, all the bolck components are perfectly balanced by hand, the factory port and polish on the head is ideal, as is the valvetrain.

i have a 97 jdm b18c-r longblock, i was planning on a full shortblock rebuild, balance, and ctr pistons... i will not be re-balancing it after reading this article. but i am wondering if the ctr pistons are manufactured with the same processes, tolereances, materials, and anit-friction coating as the itr pistons? is it worth it to up he compression to 12.1:1 if i will be running on the stock valvetrain for the next year?

any links, opinions, or experience is gretly appreciated! thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by euclid &raquo;</TD></TR><TR><TD CLASS="quote">i just finished reading an article about the manufacturing process of the jdm b18c-r.
https://honda-tech.com/zerothread?id=501863

basically it says that all the parts were designed to be used in perfect harmony, all the bolck components are perfectly balanced by hand, the factory port and polish on the head is ideal, as is the valvetrain.

i have a 97 jdm b18c-r longblock, i was planning on a full shortblock rebuild, balance, and ctr pistons... i will not be re-balancing it after reading this article. but i am wondering if the ctr pistons are manufactured with the same processes, tolereances, materials, and anit-friction coating as the itr pistons? is it worth it to up he compression to 12.1:1 if i will be running on the stock valvetrain for the next year?

any links, opinions, or experience is gretly appreciated! thanks</TD></TR></TABLE>

You can always have your CTR pistons balanced before installation, and they do have the moly coating

 

ok, my queation has evolved... is there any point in raising the compression with a stock valvetrain?

 

i believe you will be closer to 12.5 than 12.1 compression..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jonas &raquo;</TD></TR><TR><TD CLASS="quote">i believe you will be closer to 12.5 than 12.1 compression..</TD></TR></TABLE>

http://www.bojangs.com/calculator/

this may be wrong, but standard bore pct pistons and a stock headgasket rate the cr at 12.015

 

I had the same concerns when I had to install new oil rings.

My final decision was based on the fact my car was track only and running 100 octane all the time was not an issue.

Also let me say one more thing about doing this mod, as opposed to cams. Cams stress the timing belt and valvetrain.

I put out 198 WHP with the CTR pistons (~12.1:1) and the Mugen headgasket (~12.5:1) all on a stock top end.
http://home.pacbell.net/justha3/198Dyno.jpg

I suggest doing this mod for great torque, and top end power. But its not as streetable as other alternatives.

here were my engine mods to get the 198:

Civic Type R 81.25mm Pistons
JDM OE Integra Type R 4-1 Header
Custom Resonated Straight Pipe
B&M Command Flo® Fuel Pressure Regulator SET TO STOCK PSI!)
B&M Fuel Pressure Gauge
JUN Adjustable Cam Gears (Set NEARLY STOCK)
Mugen 2 Layer Head Gasket
Mugen Baffled Oil Pan
Fluidyne Radiator (no fans needed.. heh)
Hondata Intake Manifold Gasket
<FONT COLOR="red">Chipped P28 ECU with Custom DynoSpot Program</FONT>
Comptech Aluminum Lightweight Flywheel
JDM Honda OE 4.785 Final Drive
Clutchnet Stage 3 Four Puck Clutch
Clutchnet Pressure Plate

 

hm, i could have sworn sgT said it was higher than 12.1

 

thank you for the reply chris, your setup looks very similar to what i plan on running....

jdm itr longblock
ctr pistons(standard or oversized depending on the condtion of the walls)
stock valvetrain
jun/toda/or skunk cam gears
mugen, or custom baffled pan
undecided on header(comptech race, smsp, headertech)
smsp exhaust
b16a2 tranny with quaife and 4.7fd
act hdss
lightweight flywheel(fidanza or chromoly comptech)
p28 w/ hondata.
c&r radiator
hondata manifold gasket

if you are making 198whp then i will go ahead with raising the compression, this is going in a stripped 94 civic so anything above 200whp may be too much NA for my lighter chasis. it will not be daily driven after the swap.
anyway, i can always get more power out of an upgraded valvetrain down the line and it respond better with a higher cr.

btw... will i have clearance problems running a 2-layer headgasket if i decide to do toda valvtrain and jun3's down the line? thanks again

 

The compression height (distance between the wrist pin and the flat part of the piston top) is about 0.020" more on the CTR pistons, that's where the extra 0.4 CR from. The pistons basically 0.020" higher than the standard ITR pistons when used with the ITR rods.

Worth looking at the pics here much clearer than my explanation:
http://www.theoldone.com/articles/pistons/

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RICHJ &raquo;</TD></TR><TR><TD CLASS="quote">The compression height (distance between the wrist pin and the flat part of the piston top) is about 0.020" more on the CTR pistons, that's where the extra 0.4 CR from. The pistons basically 0.020" higher than the standard ITR pistons when used with the ITR rods.

Worth looking at the pics here much clearer than my explanation:
http://www.theoldone.com/articles/pistons/</TD></TR></TABLE>

exactly, so will higher lift cams present clearance problems if i further shorten the distance between the head and block with a mugen/spoon headgasket?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by euclid &raquo;</TD></TR><TR><TD CLASS="quote">

exactly, so will higher lift cams present clearance problems if i further shorten the distance between the head and block with a mugen/spoon headgasket?</TD></TR></TABLE>

Possibly, you would have to clay it and find out, it would depend on the valve reliefs I suppose. But with 12.4-12.5:1 compression with the pistons alone would you realy want to add a thinner than stock gasket??? Anything more and you would be looking at forged/custom pistons anyway.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jonas &raquo;</TD></TR><TR><TD CLASS="quote">i believe you will be closer to 12.5 than 12.1 compression..</TD></TR></TABLE>

Here we go again....

To answer your question, it depends what else you want to do, but IMO, yes. I love mine .

 

I cant understand in your first question if you are asking if the ctr pistons wont work in harmony with your jdm itr bottom end. I see no reason why a good engine builder cant balance and blueprint your whole bottom end.

chris had his bottom end built by dsr. lawrence does good work and it shows in his dyno #'s

you might want to add some 310cc injectors to be safe (im running 80% duty cycle with 180~whp on 310's)

otherwise you have a killer reliable setup

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Type R Bob &raquo;</TD></TR><TR><TD CLASS="quote">
Here we go again....</TD></TR></TABLE>

ok? nothing went on.

anyways, when i stated the 12.5, i believe i was thinking about it with a mugen head gasket, because i have one and always calculated it with it. my bad

 

If this helps at all...I'm running ctr standard bore pistons with a head milled 20k and oem head gasket along with skunk2 stage 2 cams...this may help to calm some of your concerns...Ive been running this set up for approximately 2 months, employing 93 octane as well as a j&s safeguard.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jonas &raquo;</TD></TR><TR><TD CLASS="quote">

ok? nothing went on.
</TD></TR></TABLE>

A. I was just kidding

B. I agree with you, but many people here seem not to

C. Relax

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18c-rDC2 &raquo;</TD></TR><TR><TD CLASS="quote">If this helps at all...I'm running ctr standard bore pistons with a head milled 20k and oem head gasket along with skunk2 stage 2 cams...this may help to calm some of your concerns...Ive been running this set up for approximately 2 months, employing 93 octane as well as a j&s safeguard.</TD></TR></TABLE>

No clearance issues with B18C1, 81.25 CTRs, milled 20 thou, 2 layer, BIG Todas.

 

stock cams to get 198? Can i replicate this on my stock motor with i/h/e??? The only reason I ask is that i find it really strange that toda b ppl with toda pistons only yield like 190-200whp even after pistons ...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bob-DC2 &raquo;</TD></TR><TR><TD CLASS="quote">I cant understand in your first question if you are asking if the ctr pistons wont work in harmony with your jdm itr bottom end. I see no reason why a good engine builder cant balance and blueprint your whole bottom end.

chris had his bottom end built by dsr. lawrence does good work and it shows in his dyno #'s

you might want to add some 310cc injectors to be safe (im running 80% duty cycle with 180~whp on 310's)

otherwise you have a killer reliable setup

</TD></TR></TABLE>

thanks for all the replys, i have been away this week, i will bump this thread one last time...

to answer your question, i am not planning on a rebalance after i read the link to article i posted, i was concerned the ctr pistions were built to b16a specs and therefore would not be as balanced or as durable as the itr, that question was already answered.
i am still wondering if i would have clearance problems with a smaller headgasket and higher lift cams, i still would like some input about this if anyone can help me out. thanks again