I was running ITR pistons on my LS rods and had the LS rods machined to fit the pistons. I was wondering if the rods would work with CTR pistons since they have already been shaved?

Thanks

 

I also forgot to say that the ITR pistons were shaved on the inside too. So do the CTR pistons have to be shaved also?

 

bump

 

yup

 

yup to the first question or the second?

 

as long as you got about 1mm on each side shaved on the rod, you dont have to mess with the piston at all, its actually the wrong way of going about it; the integrity of the piston is lowered by doing so.......

 

why would you switch? keep the itr's.

 

Because i got new cams and need more compression.

 

You do not need the compression ctr pistons will give you by any means.


Stick with the itr's for sure man

are they a0 or 00 p73 pistons ?

What's the block/head combo.

What are you using for cams now aswell as what cams are you putting in ?

 

[QUOTE=LG_R32]You do not need the compression ctr pistons will give you by any means.
QUOTE]

What makes you say that?
I have a B18C1 block and head, LS rods and crank, and I have a set of Pro 2 camshafts.
The ITR pistons are A0's.

 

ctr's have a big dome. and when used with big cams you have to make sure you have enough clearance.

ctr's are going to give you close to a 13:1cr

 

nah, they'll give you like 12.2:1

i cc'd my motor. ls/vtec with ctr pistons and b16 head.

 

b18c1 head will bump it just a little more. that's assuming the head hasnt been milled or block decked.

 

he'll have a **** hair more clearance since he is using the GSR block w/ the LS crank. still clay they motor either way

 

i have a b18c1 with gsr rods and ctr pistons
with buddy clubb iv

its not runnin to bad and i had the head milled to aviod warping along with the block
cometic head gasket
comprssion is about 12.23 :1
if u use a 1 layer gasket it would be around 12.97 :1

 

The CTR Piston will give you more compression that B18 Block espically if your running a b18 head too.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by demdem &raquo;</TD></TR><TR><TD CLASS="quote">The CTR Piston will give you more compression that B18 Block espically if your running a b18 head too. </TD></TR></TABLE>

yea but u would make more with a b16 head more compression and more power due to better flow

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mike K &raquo;</TD></TR><TR><TD CLASS="quote">nah, they'll give you like 12.2:1

i cc'd my motor. ls/vtec with ctr pistons and b16 head.</TD></TR></TABLE>

Then you didn't take into account the negative piston to deck height. Remember, CTRS will come out of the hole. Your compression on an LS bottom end with those pistons will be MUCH higher then 12.2:1.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid93Eg &raquo;</TD></TR><TR><TD CLASS="quote">

Then you didn't take into account the negative piston to deck height. Remember, CTRS will come out of the hole. Your compression on an LS bottom end with those pistons will be MUCH higher then 12.2:1.</TD></TR></TABLE>


but it isnt just an LS bottom end. the GSR block is taller than an LS block by .55mm. so with a LS crank/rods in GSR block the pistons will sit a bit lower than using a straight up LS bottom end.
think like this;
put a 2" stick in a 2" hole, then put that same 2" stick in a 2.25" hole, its not going to come to the top and leaves room to fill

and a dome has nothing to do with piston to deck height. it changes piston to valve/head clearance but doesnt make a piston come "out of the hole"


GSR/Type R block w/ LS crank/rods
GSR head
PCT pistons will put you in the high 11.x:1 c/r range

thats w/ out any decking or milling and a stock head gasket

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RACINTWEEK &raquo;</TD></TR><TR><TD CLASS="quote">
but it isnt just an LS bottom end. the GSR block is taller than an LS block by .55mm. so with a LS crank/rods in GSR block the pistons will sit a bit lower than using a straight up LS bottom end.</TD></TR></TABLE>

The post I responded to indicated that he CC's and LS motor with CTR pistons and got 12.x:1 compression, which is completely wrong and about 1 full point lower then it will actually be. Your speaking of a completely different bottom end then I responded about, but you are also still wrong... Let me see if I can help you also. I can see where my response in this post is going to go.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RACINTWEEK &raquo;</TD></TR><TR><TD CLASS="quote">.
think like this;
put a 2" stick in a 2" hole, then put that same 2" stick in a 2.25" hole, its not going to come to the top and leaves room to fill</TD></TR></TABLE>

Agreed, but you are essentially changing the location of your "stick" and completely left that out of the equation. This is where most people screw up in thier calculations!

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RACINTWEEK &raquo;</TD></TR><TR><TD CLASS="quote">
and a dome has nothing to do with piston to deck height. it changes piston to valve/head clearance but doesnt make a piston come "out of the hole"
</TD></TR></TABLE>

No, but COMPRESSION HEIGHT does. You apparently either

* don't know that CTR pistons have a different compression height then stock GSR/PR3 pistons
* Just simply forgot this part of the puzzle when making your calculations
* don't know what compression height is and therefore never figured it into your calculations

"normal" piston to deck height sits at ~.034 on a GSR. Thats with USDM or JDM GSR pistons. Add some ITR pistons, and you loose some, going to ~.026. Now, your beloved CTR pistons loose even more taking you to around ~.006. You should understand that as figures move toward 0, the piston is moving up the bore towards the top. As it does this, its going to increase the compression ratio. If you use the little C-speed compression calculator, it makes no change for deck height and will give you a figure around what your a telling me. The calculator is only going to be as good as the numbers you put in it. Using the correct figures, you will see that the following is true....

GSR block
GSR rods
CTR pistons
B16 head

12.7:1

Now. Take your LS crank and rods. The crank has a 1.80mm longer stroke, but your LS rods are only .90mm shorter... can you see where this is going? Your rods are shorter, yes, but you increased the stroke past the amount you decreased rod length. While PTDH will remain around the same as with the GSR parts, you increase travel of the piston in the cylinder. Long story short, you will gain a touch more compression with this combination... so...

GSR block
LS Crank
LS rods
B16 head
CTR pistons

12.9:1

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by KillaWhoKillacam &raquo;</TD></TR><TR><TD CLASS="quote">yea but u would make more with a b16 head more compression and more power due to better flow</TD></TR></TABLE>

you will LOSE a bit of compression with a b16 head. it flows nearly the same as a gsr in stock form.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid93Eg &raquo;</TD></TR><TR><TD CLASS="quote">

The post I responded to indicated that he CC's and LS motor with CTR pistons and got 12.x:1 compression, which is completely wrong and about 1 full point lower then it will actually be. Your speaking of a completely different bottom end then I responded about, but you are also still wrong... Let me see if I can help you also. I can see where my response in this post is going to go.

Agreed, but you are essentially changing the location of your "stick" and completely left that out of the equation. This is where most people screw up in thier calculations!

No, but COMPRESSION HEIGHT does. You apparently either

* don't know that CTR pistons have a different compression height then stock GSR/PR3 pistons
* Just simply forgot this part of the puzzle when making your calculations
* don't know what compression height is and therefore never figured it into your calculations

"normal" piston to deck height sits at ~.034 on a GSR. Thats with USDM or JDM GSR pistons. Add some ITR pistons, and you loose some, going to ~.026. Now, your beloved CTR pistons loose even more taking you to around ~.006. You should understand that as figures move toward 0, the piston is moving up the bore towards the top. As it does this, its going to increase the compression ratio. If you use the little C-speed compression calculator, it makes no change for deck height and will give you a figure around what your a telling me. The calculator is only going to be as good as the numbers you put in it. Using the correct figures, you will see that the following is true....

GSR block
GSR rods
CTR pistons
B16 head

12.7:1

Now. Take your LS crank and rods. The crank has a 1.80mm longer stroke, but your LS rods are only .90mm shorter... can you see where this is going? Your rods are shorter, yes, but you increased the stroke past the amount you decreased rod length. While PTDH will remain around the same as with the GSR parts, you increase travel of the piston in the cylinder. Long story short, you will gain a touch more compression with this combination... so...

GSR block
LS Crank
LS rods
B16 head
CTR pistons

12.9:1 </TD></TR></TABLE>

good ****

 

i added in the difference in deck height but not the taller piston

 

So my whole setup is going to be a B18C1 block with LS rods and crank, CTR pistons, block has been decked, Supertech valvetrain (flat faced valves), head has been milled, Pro2 cams, and a 2 ply headgasket. Valve clearance will be somewhat of a problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 92B18C1Teg &raquo;</TD></TR><TR><TD CLASS="quote">So my whole setup is going to be a B18C1 block with LS rods and crank, CTR pistons, block has been decked, Supertech valvetrain (flat faced valves), head has been milled, Pro2 cams, and a 2 ply headgasket. Valve clearance will be somewhat of a problem.</TD></TR></TABLE>

Stick With the ITR's your head has been milled already and your running 2ply gasket that should give you enough compression for those cams ctr's are going to push it....

 

Does anyone know what's an adequate compression ratio for these cams?