As the title says... Im building and ls/vtec all motor setup and I been reading a lot about different peoples setups but im stuck on a few questions. What rods are prefered when using ITR pistons and what about CTR pistons?

 

keep the LS rods, just get new bearings and ARP rod bolts(8mm).

 

ls rods on ITR or CTR pistons will work? what about preferences for aftermarket...planning on taking the motor to a 9k redline ls/vtec so ls rods strong enough?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tphan4 &raquo;</TD></TR><TR><TD CLASS="quote">ls rods on ITR or CTR pistons will work? what about preferences for aftermarket...planning on taking the motor to a 9k redline ls/vtec so ls rods strong enough?</TD></TR></TABLE>

Yes, they will fit,b ut you half to machine the LS rods .5mm on each side. If you plan on going to 9K get the rods shotpeened and you will be fine.

 

Your comprssion is going to be crazy high, why not get p30's which dont have to be machined and run lesser compression that you can actually use with pump gas...

 

IF you run CTR's you will have high compression and be limited on what cams you can run!!!!!

 

we have 93 octane here in New england...so not so bad... I was hoping along the lines of 12:1 or 13:1 compression....also wats recommended for cams?

 

definitely Crower 404's or bigger. Crower 405's or Crane #20's!

 

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

Yes, they will fit,b ut you half to machine the LS rods .5mm on each side. If you plan on going to 9K get the rods shotpeened and you will be fine.</TD></TR></TABLE>

get the rods shotpeened, what this do? im sorry im new to building motors also. and im doing a ls/vtec with all same ?s

 

crower 404s for a street car i had 405a in my ls all motor and they were a rough street drive i had to swap out for 404

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicrida3 &raquo;</TD></TR><TR><TD CLASS="quote">

get the rods shotpeened, what this do? im sorry im new to building motors also. and im doing a ls/vtec with all same ?s </TD></TR></TABLE>

it will strengthen the rods.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LG_R32 &raquo;</TD></TR><TR><TD CLASS="quote">crower 404s for a street car i had 405a in my ls all motor and they were a rough street drive i had to swap out for 404</TD></TR></TABLE>

What did you do with the 405's? Maybe interested in buying.

 

i say go with the CTR pistons (.25 over) on the stock LS rods and get some ARP bolts. CTR VS ITR. CTR=bigger dome = higher compresion

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicstar11 &raquo;</TD></TR><TR><TD CLASS="quote">i say go with the CTR pistons (.25 over) on the stock LS rods and get some ARP bolts. CTR VS ITR. CTR=bigger dome = higher compresion</TD></TR></TABLE>

yeah more compression , but does he have the fuel to run that kind of compression?

 

CTR's in an LS block with an unmilled LS head and a factory Headgasket yield 12.3:1 to 12.4:1 static compression. The CTR Piston has a 0.000 Piston to Deck clearance in an LS b/c the compression height is 1.21" compares to the stock LS compression height of 1.18".

 

how about that set up with a b16 head ? whats the comp? too much?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicrida3 &raquo;</TD></TR><TR><TD CLASS="quote">how about that set up with a b16 head ? whats the comp? too much? </TD></TR></TABLE>

I'd have to calculate that but it would be real high, close to 13:1

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybrid_vtec &raquo;</TD></TR><TR><TD CLASS="quote">CTR's in an LS block with an unmilled LS head and a factory Headgasket yield 12.3:1 to 12.4:1 static compression. The CTR Piston has a 0.000 Piston to Deck clearance in an LS b/c the compression height is 1.21" compares to the stock LS compression height of 1.18".</TD></TR></TABLE>

piston to deck clearance of 0....hmmm....am i not the only one seeing the pistons goin smack once the rods stretch on a good rev?

 

So ITR(P73) and CTR(PCT) pistons on an LS need rod modification and the B16(P30) pistons bolt right up?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by iv &raquo;</TD></TR><TR><TD CLASS="quote">IF you run CTR's you will have high compression and be limited on what cams you can run!!!!!</TD></TR></TABLE>
verry true

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tphan4 &raquo;</TD></TR><TR><TD CLASS="quote">we have 93 octane here in New england...so not so bad... I was hoping along the lines of 12:1 or 13:1 compression....also wats recommended for cams?</TD></TR></TABLE>
even on 93 you will have detonation issues you will need alot alot of tuning

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sheepeg3 &raquo;</TD></TR><TR><TD CLASS="quote">
yeah more compression , but does he have the fuel to run that kind of compression?</TD></TR></TABLE>
i use 100 all the time and i always keep some octane booster if i have to use 93

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybrid_vtec &raquo;</TD></TR><TR><TD CLASS="quote">
I'd have to calculate that but it would be real high, close to 13:1</TD></TR></TABLE>
i thougth that ctr pistons in a ls block with a b16 head would be aroung 12.3??

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EG6R &raquo;</TD></TR><TR><TD CLASS="quote">So ITR(P73) and CTR(PCT) pistons on an LS need rod modification and the B16(P30) pistons bolt right up?</TD></TR></TABLE>
you are correct
if you can afford to get after market rods get them sopeened rods are fine but can still fail

 

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


i use 100 all the time and i always keep some octane booster if i have to use 93
</TD></TR></TABLE>

now let me ask you this. Octan booster really help? I a manager at Autozone, and I have access to all that mombo jombo but honestly i have never bought it cuase i didnt think it would work. Theres the NOS offroad one and says 8 points increase but i dunno. Give me more feedback on what octane booster does really increase points beacuse im about to start runin a high compression motor and octane booster will be free if i need it

 

ok here you go I calculated it out this morning:


CTR(pct) Pistons in:

Stock B16a: 11.8:1

Stock B18a/b: 12.4:1

LS/Vtec w/ stock HG: 13.1:1


If the number sound off to you, remember that the CTR have a .030" difference in compression height.

Compression Height:

B16a PR3: 1.18"
B18a PR4: 1.18"
B16b PCT: 1.21"

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2k.civic.si &raquo;</TD></TR><TR><TD CLASS="quote">

piston to deck clearance of 0....hmmm....am i not the only one seeing the pistons goin smack once the rods stretch on a good rev?</TD></TR></TABLE>

I understand what you are saying, and it is an issue that could likely happen but I have never seen it happen yet. To be honest through, factory cast parts for the most part only expand so much under heat.

However this is why it is very importantto clay the motor. I would be concerned more for the B16 guys. In a B16a the factory piston to deck clearance is 0.020". So with CTR's it would become -0.010"!!!! That's .010" out of the hole!! Talk about flirting with disaster!!

For the LS guys , we can run the CTR's b/c we have a little more room to play with than you Vtec guys. Although we still have to be careful, you guys will have less room for Pistons to valve clearance, so claying the motor becomes vital!

 

i already sold the 405s they were an amazing cam but just a bit to harsh for daily driving lol

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicrida3 &raquo;</TD></TR><TR><TD CLASS="quote">

get the rods shotpeened, what this do? im sorry im new to building motors also. and im doing a ls/vtec with all same ?s </TD></TR></TABLE>

actually the rods are already shot peened. when people say get your rods "shot peened" what they are really talking about is grinding the forging flashing smooth. doing this relieves potential areas where stress cracks can form.

after that is done, the rods need to be re-shot peened.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybrid_vtec &raquo;</TD></TR><TR><TD CLASS="quote">ok here you go I calculated it out this morning:
CTR(pct) Pistons in:
Stock B16a: 11.8:1
Stock B18a/b: 12.4:1
LS/Vtec w/ stock HG: 13.1:1
If the number sound off to you, remember that the CTR have a .030" difference in compression height.
</TD></TR></TABLE>

they sound off cause they are off....
stock b16a with ctr pistons
cyl vol. 398.6cc
head Gasket 2.8cc
piston dome vol. 6.3cc big vol= 436.8
camber vol. 44cc small vol= 38.2 ..stock b16a=11.43
deck height .5mm+ 2.3cc

lsvtec with b16 head and ctr pistons
head Gasket 2.8cc big vol= 497.6cc
piston dome vol. 6.3cc small vol= 39.2cc ..stock lsvtec=12.7
camber vol. 44cc
deck height .25mm 1.3cc
cyl vol. 458.4cc

lsvtec with gsr head and ctr pistons
head Gasket 2.8cc big vol= 495.6cc
piston dome vol. 6.3cc small vol= 37.2cc ..stock gsr/lsvtec=13.3
camber vol. 42cc
deck height .25mm 1.3cc
cyl vol. 458.4cc

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2k.civic.si &raquo;</TD></TR><TR><TD CLASS="quote">

they sound off cause they are off....
stock b16a with ctr pistons
cyl vol. 398.6cc
head Gasket 2.8cc
piston dome vol. 6.3cc big vol= 436.8
camber vol. 44cc small vol= 38.2 ..stock b16a=11.43
deck height .5mm+ 2.3cc

lsvtec with b16 head and ctr pistons
head Gasket 2.8cc big vol= 497.6cc
piston dome vol. 6.3cc small vol= 39.2cc ..stock lsvtec=12.7
camber vol. 44cc
deck height .25mm 1.3cc
cyl vol. 458.4cc

lsvtec with gsr head and ctr pistons
head Gasket 2.8cc big vol= 495.6cc
piston dome vol. 6.3cc small vol= 37.2cc ..stock gsr/lsvtec=13.3
camber vol. 42cc
deck height .25mm 1.3cc
cyl vol. 458.4cc

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

I see you took those from Omniman's post!

Well I do know I have the Compression number for the CTR's in an LS correct! I must have the wrong measurements for Vtec heads is all I can think of! Maybe I used the number for a P72 head instead of a PR3!

Oh well, my bad. I stand corrected!