What is the compression of CTR pistons? Is CTR better then ITR?

 

i believe it raises ur cr.

 

depends what setup you have them in. if your talking about them in an itr, your comp should be around 11.7-11.8 give or take.

 

But which one is higher? the ctr or the itr?

 

oh. ctr of course. much higher

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SouthSideRacing &raquo;</TD></TR><TR><TD CLASS="quote">What is the compersion of CTR pistons? Is CTR better then ITR? </TD></TR></TABLE>


It all depends what you put them in......ctr piston have a higher dome wich gives you higher comp... in an itr block thcr should be 11.5-11.7.1 , but in a b16a the deck hieght is lower so the piston creates higher cr. in a b16a the cr should be 11.9-12.1.1.

 

how does one figure out their compression ratio? i was told i have ctr pistons when i bought the car, but can i tell for sure without pulling the head?

 

http://www.geocities.com/Motor...s.htm

that should answer all your questions.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTECDC2 &raquo;</TD></TR><TR><TD CLASS="quote">how does one figure out their compression ratio? i was told i have ctr pistons when i bought the car, but can i tell for sure without pulling the head?</TD></TR></TABLE>

what block do you have??

 

http://www.c-speedracing.com/h...c.php

 

Sorry to steal the thread, but just wondering what all i need to be able to handle CTR pistons in my USDM GSR motor? Besides upgraded fuel and tuning. I dont need a better valvetrain at this moment do I? I dont have the money for that.

 

You're way off on those numbers, for the b16a anyways. With an OEM headgasket and stock b16a head (not decked) the CR is 10.8:1. The deck height is less with the b16a but there are other things that affect the CR. It's not over 11 with CTR pistons and OEM headgasket in a b16a.

On an ITR block you're pretty close. ITR head, OEM headgasket and b18c block the CR is about 11.75:1.

 

2nd gen b16a.. according to that site, guess im supposed to have 12:1.. how can i tell for sure? i want to know if i really do have the CTR pistons, but i dont want to pull the head. is there another way?

 

CTR's hands down, and it doesnt matter what block you have it in....CTR will always be higher then ITR's (if both was to be in the same block..)

 

they are completely different.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTECDC2 &raquo;</TD></TR><TR><TD CLASS="quote">2nd gen b16a.. according to that site, guess im supposed to have 12:1.. how can i tell for sure? i want to know if i really do have the CTR pistons, but i dont want to pull the head. is there another way?</TD></TR></TABLE>

You're using the wrong numbers, or else they are just wrong.

2nd gen B16A has 10.2:1 CR stock, add to that the CTR piatons and you should have around 10.8:1 CR, which is the same CR as a stock B16B motor.

No stock Honda B motor makes over 11:1 stock, and that's the B18C Type R motor in Japan.

Compression isn't just about the piston domes, it's also about placement on the rod, combustion chamber volume in the head, head gasket thickness, milling on the block and/or head, bore, stroke, etc.

To answer the question though, the CTR pistons have the highest dome on them in terms of factory honda pistons.

They will raise the CR in any B series motor that you put them in except for, of course, the B16B CTR motor.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C5-EH2 &raquo;</TD></TR><TR><TD CLASS="quote">

You're using the wrong numbers, or else they are just wrong.

2nd gen B16A has 10.2:1 CR stock, add to that the CTR piatons and you should have around 10.8:1 CR, which is the same CR as a stock B16B motor.

No stock Honda B motor makes over 11:1 stock, and that's the B18C Type R motor in Japan.

Compression isn't just about the piston domes, it's also about placement on the rod, combustion chamber volume in the head, head gasket thickness, milling on the block and/or head, bore, stroke, etc.

To answer the question though, the CTR pistons have the highest dome on them in terms of factory honda pistons.

They will raise the CR in any B series motor that you put them in except for, of course, the B16B CTR motor.

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

hmmmmmmm.. it was to my understanding that ctr pistons in a b16a make around 12.1.1 cr because oof a lower deck hieght.This was told to me by dr. charles, and numerous other friends at area 51 fabrications. IT makes sense to me , but what your saying makes sense as well. Not saying your wrong or anything, but i am a bit confused. if you are right then i am getting a thinner head gasket tomorrow.

 

I'd have to check the deck height again, but I've not seen the deck height vary from the B16A and B16B on any CR calculators, but then again it might make sense since the B16B is the exact same block as the B18C.

Hmmm...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C5-EH2 &raquo;</TD></TR><TR><TD CLASS="quote">I'd have to check the deck height again, but I've not seen the deck height vary from the B16A and B16B on any CR calculators, but then again it might make sense since the B16B is the exact same block as the B18C.

Hmmm...</TD></TR></TABLE>

Ya i thought a b16b is a 1.8 block with a destroked crank, and that is why the deck hieght of a b16a is lower cause it is a "true" 1.6. i have iasked i few people again....most people say 11.9.1-12.1.1.......but some people on the site say 10.8.1?who knows? if you figure it out let me know. has anyone with ctr pistons in a b16 passed smog? with or without stck cams.......cause i can easily put my stock ones in????

 

in an itr the cr with ctr pistons is slightly above 12.0:1 with the stock 3-layer headgasket. it is slightly above 12.3:1 in a gsr with stock headgasket.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by euclid &raquo;</TD></TR><TR><TD CLASS="quote">in an itr the cr with ctr pistons is slightly above 12.0:1 with the stock 3-layer headgasket. it is slightly above 12.3:1 in a gsr with stock headgasket. </TD></TR></TABLE>

Nope. It's doesn't go over 12:1 with CTR pistons and an ITR block/head and stock headgasket.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by stevel &raquo;</TD></TR><TR><TD CLASS="quote">
On an ITR block you're pretty close. ITR head, OEM headgasket and b18c block the CR is about 11.75:1.

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

It's almost exactly 12:1 with a gsr block/head with CTR pistons.

According to the c-speedracing CR calculator. It seems to be right. If you put in a stock config it's dead on. Don't know why so much controversey over this.

s

 

i have ITR pistons and shotpeened LS rods, i plan on getting type r cams..will i need to change the valvetrain?

 

This site is the bomb for figuring compression ratios: http://www.bojangs.com/calculator/

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by USDMDC2NH &raquo;</TD></TR><TR><TD CLASS="quote"> This site is the bomb for figuring compression ratios: http://www.bojangs.com/calculator/</TD></TR></TABLE>

thats thats total wrong!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nocaryet &raquo;</TD></TR><TR><TD CLASS="quote">i have ITR pistons and shotpeened LS rods, i plan on getting type r cams..will i need to change the valvetrain?</TD></TR></TABLE>

you should try to get at least type valvetrain..........or better if you want to rev out