With a jdm motor, by adding the ctr pistons, will this get my compression to bout 12.5 with a stock head gasket? The reason for asking is because my motor is smoking alot due most likely to piston rings, and I want to do an all motor build but still be daily driven. Ive search and some ppl say that itll be 13+ and some say a little of 12. Which is it? thanks for the help.

 

12:1 on my R. But if your rebuilding the block why get CTR's?

 

bc I can pick up a whole set with rings for 150

 

Also jw, how much does it usually cost for a shop to install pistons?

 

I hope you know that those pistons are going to require alot more than just installation. If it were me, I would opt for a set of P30 pistons if I were going to rebuild with OE pistons.

 

I agree, you need to do more research before doign this. I have had those pistons in my R for 3 years now and I can tell you all that compression, clearance, etc isn't something you want to mess with without proper knowledge.

 

go with stock ITR pistons, i can ran CTR's and i'm wondering if they were the cause of a lot of my built issues, just FYI

 

CTR pistons suck, take it from someone that has them.

Dome is way too high.

 

Shouldn't be a prob with a good build and proper engine mgmt. My shop charged me an extra $150 to put in CTR pistons when I rebuilt my C5. I ran 94 octane and it was a beast. Check the walls for roundness, etc., etc., before throwing them in there(basically all the things you would do anyways during a rebuild). There were a lot of naysayers on here, but if you do it RIGHT, you'll be fine. IM me if you are serious and want more specifics. The dome is high, but I have no idea why that sucks, when a lot of non-oem(toda etc.) have higher compression ratios than CTR's, and have no clearance issues what-so-ever, it all goes back to the build(DON'T HALF-*** IT).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LootR0435 &raquo;</TD></TR><TR><TD CLASS="quote">Shouldn't be a prob with a good build and proper engine mgmt. My shop charged me an extra $150 to put in CTR pistons when I rebuilt my C5. I ran 94 octane and it was a beast. Check the walls for roundness, etc., etc., before throwing them in there(basically all the things you would do anyways during a rebuild). There were a lot of naysayers on here, but if you do it RIGHT, you'll be fine. IM me if you are serious and want more specifics. The dome is high, but I have no idea why that sucks, when a lot of non-oem(toda etc.) have higher compression ratios than CTR's, and have no clearance issues what-so-ever, it all goes back to the build(DON'T HALF-*** IT).</TD></TR></TABLE>

You are right for the most part. But if hes building the bottom end anyway, why do CTR's? There are many better ones out there.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LootR0435 &raquo;</TD></TR><TR><TD CLASS="quote">but if you do it RIGHT, you'll be fine. IM me if you are serious and want more specifics. The dome is high, but I have no idea why that sucks, when a lot of non-oem(toda etc.) have higher compression ratios than CTR's, </TD></TR></TABLE>

I am sorry but that made me laugh, I guess it's time for me to be technical now.

Go compare the weight of a CTR piston to any other pistons. You would be astonished at how heavy they are compared to everything else.

The CTR piston dome is too big. Why is this bad? This causes hot spots on the pistons and creates detonation. Forcing you to run more relaxed timing.

Yes compression creates power, but the CTR pistons creates compression inefficiently. A better designed, lighter piston with lower compression can create more power then a CTR piston on less compression.

And trust me, I am not saying the CTR pistons are garbage. I have no problem with them, I personally have them in my engine. But there are better options out there.

 

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

I am sorry but that made me laugh, I guess it's time for me to be technical now.

Go compare the weight of a CTR piston to any other pistons. You would be astonished at how heavy they are compared to everything else.

The CTR piston dome is too big. Why is this bad? This causes hot spots on the pistons and creates detonation. Forcing you to run more relaxed timing.

Yes compression creates power, but the CTR pistons creates compression inefficiently. A better designed, lighter piston with lower compression can create more power then a CTR piston on less compression.

And trust me, I am not saying the CTR pistons are garbage. I have no problem with them, I personally have them in my engine. But there are better options out there.

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


you'd be astonished the amount of people i have advised against PCT pistons, only for them to turn round and say "well Honda put them in the CTR, they've got to be good, stop being an idiot you don't know what you're talking about."


i then have to remind them that 10x in my post to help reiterate the point is that YES PCT pistons work in raising compression, BUT THAT THERE ARE BETTER OPTIONS OUT THERE, and not to keep believing in the fact bigger dome is best.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Comp97GSR &raquo;</TD></TR><TR><TD CLASS="quote"> If it were me, I would opt for a set of P30 pistons if I were going to rebuild with OE pistons. </TD></TR></TABLE>

x2

either my stock pistons or some P30's

 

P30's or PR3's FTMFW!

In all seriousness though, PCT pistons do have an obstructive dome.

The ideal piston is flat.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tartje &raquo;</TD></TR><TR><TD CLASS="quote"> YES PCT pistons work in raising compression, BUT THAT THERE ARE BETTER OPTIONS OUT THERE, and not to keep believing in the fact bigger dome is best.
</TD></TR></TABLE>

Agreed. According to our friend LootR0435, since "non-oem" companys make pistons that equal to higher compression numbers, this must make CTR pistons a good choice:

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LootR0435 &raquo;</TD></TR><TR><TD CLASS="quote">The dome is high, but I have no idea why that sucks, when a lot of non-oem(toda etc.) have higher compression ratios than CTR's, and have no clearance issues what-so-ever</TD></TR></TABLE>

I am by no means an expert, but I hate to be an *******. It annoys me when people with hardly any knowledge of the subject try to make a recommendation. There is so much more then compression numbers to come into effect when choosing a piston... forged, cast, wrist pin locations, weight, dome shape, gas ported, etc... And here we have have people thinking that if toda and etc.. make higher compression pistons then the CTRs must be good too.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 92TypeR &raquo;</TD></TR><TR><TD CLASS="quote">

The ideal piston is flat.</TD></TR></TABLE>

Agreed.

Lets think about this. A piston with a large dome creates hot spots (which cause detonation) as the energy from the combustion is distributed unevenly. A flat top pistons distributes energy most efficiently and is the ideal for preventing detention caused by hot spots.

Furthermore, pistons with large dome equal trouble for your valves. Cams with a high lift and duration numbers will prevent you from adjusting your cam gears to desired specifications, you will need to compensate for the small piston to valve clearances. Likewise, this will limit and/or prevent you from using a cam with a high/lift duration.

So with the above information being disclosed, lets use some common sense here LootR0435, and please explain to me how the following is a valid statement:

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LootR0435 &raquo;</TD></TR><TR><TD CLASS="quote">CTR's, and have no clearance issues what-so-ever</TD></TR></TABLE>

This topic has been discussed more then enough times in the past, it is like beating a dead horse if you want to continue any furthor with this debate.


Modified by neo_ at 4:26 AM 9/20/2007

 

Neo, I agree with you 100%.

Personally I have been running Toda C cams shafts with adjusted cam gears and CTR's without any clearance issues. But I wouldn't dare runnign anything with more duration while using those pistons.

To the original poster, simply put, do more research and get a better piston. There are a few options out there.

 

Thanks for the replies. You all have been very helpful. So what are some generally good pistons to use? That dont cost too much.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by skata89 &raquo;</TD></TR><TR><TD CLASS="quote">Thanks for the replies. You all have been very helpful. So what are some generally good pistons to use? That dont cost too much.</TD></TR></TABLE>

P30 or PR3 (JDM B16) Pistons work well on 1.8 motors

 

CTR's are crap. Heaviest OEM B series piston, tall *** dome. Sorry if this was covered already.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Aquafina &raquo;</TD></TR><TR><TD CLASS="quote">CTR's are crap. Heaviest OEM B series piston, tall *** dome. Sorry if this was covered already.</TD></TR></TABLE>

That, and so much more.

 

Went ahead and read the whole thread.

The high dome interferes with flame travel. The flame has to travel over the dome, which takes longer. Ideally you want a flat top and a combustion chamber with quench pads. The squish from the pads along with the flat top puts the A/F mixture right in the middle of the chamber, versus pushing it to the sides like a domed piston does. This gives you a more efficient burn, making more power with less work.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 92TypeR &raquo;</TD></TR><TR><TD CLASS="quote">

P30 or PR3 (JDM B16) Pistons work well on 1.8 motors</TD></TR></TABLE>

...and they are lighter than their ITR and CTR counterparts. USDM PR3's wouldn't be too bad if you can not find the JDM P30's.

 

Yep, i make stock itr power with my jdmb16 with just itr cams

 

how much more compression would p30's make over jdm itr pistons? i recalling reading somewhere that the difference was minimal, because the skirt height wasn't taken into account, or something to that effect

 

If you CC out your combustion chamber with P30's, it would be near 11.5:1

 

so 11.5 (p30) vs 11.1 (jdm itr), seems like a minimal bump in compression