What would be the compression???

Did a search and can't find anything on a Type R engine with CTR pistons only GSR.

Thanks

 

Ctr's in a Itr make around 11.8.1 compression....perfect for some jun 3's!!!!!

 

thanks

 

Do a search in the ITR forum. You will find like 50 threads on it.

It does NOT make 11:8:1

It makes at least 12:1:1

Look it up.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by WayneGro &raquo;</TD></TR><TR><TD CLASS="quote">Do a search in the ITR forum. You will find like 50 threads on it.

It does NOT make 11:8:1

It makes at least 12:1:1

Look it up. </TD></TR></TABLE>

Correct! This has been gone over a thousand times, it makes compression in the low to mid 12's. Let the non believers start flaming............(and btw, I have ctr's in my ITR)

 

i believe the compression is more than 12:1. i run a gsr block with ctr pistons with a stock itr head and stock headgasket. Tuned with hondata i put down 191whp with a carsound cat, jdm 4-1, and rs-r exhaust so i think its they are good for some power.

 

Ya they at least make 11.8.1, more likely 12.......But it is up there

 

this site might help you guys...its pretty accurate....good luck!

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

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MugenEK9grl &raquo;</TD></TR><TR><TD CLASS="quote">this site might help you guys...its pretty accurate....good luck!

http://www.c-speedracing.com/h...c.php
</TD></TR></TABLE>

Problem w/ this calculator is that it fails to take into account the fact that CTR pistons sit higher on the rod than most (if not all) 81mm oem pistons, hence the argument about whether or not the compression is over 12:1 on a b18c5.

 

So than what is it???? I mean there is a lot of agruments here from what I can see, but is there a way to actually measure this??? And if yes has anyone ever done this?

 

You might be better off doing JDM ITR pistons and cutting the head for the exact compression you want. You'll get better combustion with a flatter piston. The CTR has a pretty agressive dome.

 

That is the last thing I would do! Shaving the head is never a good thing.

Could someone help me with this question then? If I went with CTR pistons in my ITR engine and used 2-leyer head gasket to bump the compression a little bit higher would there be any issues with the stock sized valve clearance as well as 0.5mm oversize valves???

Thanks.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Screamer &raquo;</TD></TR><TR><TD CLASS="quote">That is the last thing I would do! Shaving the head is never a good thing.

Could someone help me with this question then? If I went with CTR pistons in my ITR engine and used 2-leyer head gasket to bump the compression a little bit higher would there be any issues with the stock sized valve clearance as well as 0.5mm oversize valves???

Thanks.</TD></TR></TABLE>

What are you talking about, why is shaving a head a bad thing? Any good machine shop is going to shave your head in order to get a flat surface. Using a thin head gasket is, in effect, the same as shaving your head.

 

<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">

Correct! This has been gone over a thousand times, it makes compression in the low to mid 12's. Let the non believers start flaming............(and btw, I have ctr's in my ITR)</TD></TR></TABLE>


maybe even more than 1000 times....but not as bad as the eg forum....which rims (wheels) should i get guys?!??!

 

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

What are you talking about, why is shaving a head a bad thing? Any good machine shop is going to shave your head in order to get a flat surface. Using a thin head gasket is, in effect, the same as shaving your head.</TD></TR></TABLE>


exactly.....shaving, decking the head....all good!!! all my heads have been shaved or decked!

 

Shaving to get a flat surface YES (even necessary), but shaving to increas CR by almost a point bad idea. You will screw up your timing.

 

Ive driven and riden several times in a ITR with CTR pistons. Runs perfect on 91, all else is stock on the car other than pistons. Stock ECU, Stock injectors... Stock everything, just the CTR pistons and thats it.

 

Would you know what numbers it put down?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Screamer &raquo;</TD></TR><TR><TD CLASS="quote">Shaving to get a flat surface YES (even necessary), but shaving to increas CR by almost a point bad idea. You will screw up your timing.
</TD></TR></TABLE>

Once you screw your timing up you fix it by cutting a new key or using adjustable cam gears. Whoever builds your motor should be able to tell you exactly how much to retard the cams relative to the material removed from the head.

You would still be better off with JDM ITR pistons and .20" off the head.

Edit: Or better yet, rather than getting on-line and asking what your CR is going to be with this part or that... go to an engine builder and tell them exactly what static CR you want to have.

 

I will be running Jun cams in it so I don't really care about static compression... why do people on this board always have to behave like a smarta$$ without knowing the whole story. All I asked is for the CR cause that is all that I needed to know. I don't need anyone trying to preach to me.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Screamer &raquo;</TD></TR><TR><TD CLASS="quote">I will be running Jun cams in it so I don't really care about static compression... why do people on this board always have to behave like a smarta$$ without knowing the whole story . All I asked is for the CR cause that is all that I needed to know. I don't need anyone trying to preach to me. </TD></TR></TABLE>

thats honda-tech for you bro but you got your answer already have fun

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Screamer &raquo;</TD></TR><TR><TD CLASS="quote"> All I asked is for the CR cause that is all that I needed to know. I don't need anyone trying to preach to me. </TD></TR></TABLE>

Hey man, sorry you took my posts that way. I jumped in when you said:
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">So than what is it???? I mean there is a lot of agruments here from what I can see, but is there a way to actually measure this??? And if yes has anyone ever done this?
</TD></TR></TABLE>

All I was suggesting was that if you were unsure of the compression, you might want to go a little on the conservative side (JDM ITR) and have the machine shop cut the head for the exact compression you wanted.

You replied suggesting that cutting the head was a bad thing to do. I disagreed with you. No preaching.

Btw - static compression is the compression ratio.

 

No hard feelings here... just wanted a simple answer that is all (if there is such a thing ).

Btw - static compression is the compression ratio. (Yes, but is greatly influenced by the cams you run.)

Thanks for great replies to everyone!!!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Screamer &raquo;</TD></TR><TR><TD CLASS="quote">Btw - static compression is the compression ratio. (Yes, but is greatly influenced by the cams you run.)</TD></TR></TABLE>

Can you explain what you mean by that? Thanks.

 

Sure - in short - the less duration on the cams you run and the higher the cr the more static compression. The higher the duration on the cams you run (more overlap) the lower the static compression.