I did a search and could not find anythig, my question is, if I install ctr pistion along with skunk2 stage 2 cams, will the vavles hit the pistions? I will be installing them into a stock gsr motor with no head/block decking. Also, what compression ratio i'm i looking at with this set-up. Any help will be great.
thanks

 

clay the motor to find out...cr is in the low-mid 12's i beleive

 

no they wont hit. friend had this setup even with a milled head. very little room to tune the gears though.

 

ths will help you figure out the compression, it's like 12.1 http://www.c-speedracing.com/h...c.php

 

thats alot of dome for the GSR head with those CTR's in there. The valve releifs arent very deep on those pistons so it will be close. even closer with those cams. I would DEFINETELY clay the motor on that setup. but i do agree that you will have very little room to adjust the cam gears. i wouldnt take it pass 2 degrees.
think about maybe using some b16 pistons, p30's, in there. they should give you a real nice streetable compression and nice compression for those cams
less dome, deeper releifs. should be around 11.5 CR with them and they will fit directly on those rods.no modifications.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1meanB18c5civic &raquo;</TD></TR><TR><TD CLASS="quote">thats alot of dome for the GSR head with those CTR's in there. The valve releifs arent very deep on those pistons so it will be close. even closer with those cams. I would DEFINETELY clay the motor on that setup. but i do agree that you will have very little room to adjust the cam gears. i wouldnt take it pass 2 degrees.
think about maybe using some b16 pistons, p30's, in there. they should give you a real nice streetable compression and nice compression for those cams
less dome, deeper releifs. should be around 11.5 CR with them and they will fit directly on those rods.no modifications.</TD></TR></TABLE>
the valve reliefs are the same for PCT pistons and any other vtec pistons, such as P30, P73, etc...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by allmtr &raquo;</TD></TR><TR><TD CLASS="quote">
the valve reliefs are the same for PCT pistons and any other vtec pistons, such as P30, P73, etc...</TD></TR></TABLE>
not all honda pistons are designed the same. Also, piston to deck height will help determine how much clearance(depth) is between the valves and pistons. All honda motors have the same piston to valve clearance...not the same valve relief depth. 2 different things.
Think.. CTR cams need more valve relief space then b16 cams. same clearances, different piston to deck height, different valve relief depth.
you can visually see a difference in p72 valve depth and p30's. i have a set here ..i'm looking at em.



Modified by 1meanB18c5civic at 4:44 AM 10/4/2003

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1meanB18c5civic &raquo;</TD></TR><TR><TD CLASS="quote">
not all honda pistons are designed the same. Also, piston to deck height will help determine how much clearance(depth) is between the valves and pistons. All honda motors have the same piston to valve clearance...not the same valve relief depth. 2 different things.
Think.. CTR cams need more valve relief space then b16 cams. same clearances, different piston to deck height, different valve relief depth.
you can visually see a difference in p72 valve depth and p30's. i have a set here ..i'm looking at em.</TD></TR></TABLE>
Ok, first of all, the piston to deck hight should not be a problem at all since the piston should be at TDC no matter what. just cuz the CTR block has 7mm more deck height than the b16's, doesnt mean it has a different piston to deck height. the rods will compensate for that and put the piston at TDC.
And second, if ctr cams need more valve reliefe space, wouldnt that mean that the ctr pistons have a deeper valve relief (according to you.) however all vtec pistons have valve reliefs to accomodate for the 33mm intake valves of the vtec head, no matter what honda cams used.


Modified by allmtr at 9:05 AM 10/4/2003

 

yeah he is saying that all vtec heads have the same circumfrence of the valve reliefs 33mm but that has nothing to do with the actual depth of those reliefs he is saying the actual depth is different on different pistons

 

i dont understand.. there just skunk stage 2 cams with ctr pistons, the cams will work great with that compression even tho it will be close right?? what if he got stage 3s he would need higher compression pistons, in that sense it will hit?! i thought you needed high comp to take advantage of big cams, but risk the danger of pistons hitting valves.. hmmm

 

just off the topic i was wondering if i could run skunk2 stage 2 with a ls vtec with ctr pistons against a gsr head i don't know if the valves will hit or not any one running a setup like this
thanks

 

when u start getting higher you will order aftermarket forged pistons with deeper valve reliefs .

 

damn, looks like i started the great debate. well, would you guys recommend a different piston to run with this set-up? everyone says i will need higher compression to take advantage of the cams. what about jdm itr's? anyway, thanks for the help everybody

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civic97dx &raquo;</TD></TR><TR><TD CLASS="quote">damn, looks like i started the great debate. well, would you guys recommend a different piston to run with this set-up? everyone says i will need higher compression to take advantage of the cams. what about jdm itr's? anyway, thanks for the help everybody</TD></TR></TABLE>
CTR pistons yield a higher C/R than JDM ITR pistons. the compession will be perfect for the use of skunk stage 2 cams

 

so you think sticking with the ctr's would be the better way to go? I'm just scared to **** something up. anyway, thanks again you guys

 

you can run CTR pistons with the stage II cams in your GSR motor. It should be fine- barring any machine work that's been done. The CTR pistons are a great OEM way to bump the compression for use with those cams.

 

Does anyone know how far you can advance or retard the cam and not have piston to valve contact or Valve to Valve contact ?

 

stock valves? or oversize?

 

Stock

 

damn you read my mind, people have told me only a few degrees. is that true? if that's the case,should i just sell the gears?

 

I believe you can adjust them together with the same amount of retard and advance up to 6 degrees and not valve to piston contact but when you retard and advance the cam gears independently you can not have more than 1 or 2 degrees difference between them without running the risk of valve to valve contact.

I did have my motor clayed when I installed the CTR pistons 0.25 over and Stage 2 cams and stock head height and stock head gasket, and I was able to advanced/retarded both gears up to 6 degrees and they didn't even touch the clay. I stopped at 6 degree because I remember reading something about if I have to advance my cams that far they might be to big for my setup. So, I stopped at 6 degree. The only thing that claying doesn't account for is vavle to valve contact.

 

thank you very much, that's what i wanted to hear. I'll be running a stock head gasket, no head mill and standard bore ctr's. want kind of power did your set-up put down? I'm kinda curious to see what people are getting.

 

Jeff at import builder put down about 205 with hondata tunning.

 

that's cool, i'll be running a s200 so that will work out good. thank you for your help. you helped convence me that i'm going in the right direction.
thanks