Im working on an LS VTEC setup right now. My question is, how many of you running LS VTEC are running LS pistons in the setup instead of ctr's or any other piston. Just curious as to what some of the power outputs have seen. Im going to be building a full bottom end in the next year anyhow, but i was just curious to see what some of you guys have done with ls pistons.

Please dont tell me to search ive read over 11 pages worth of ls/vtec post over the last two days

 

go to the import review website, they have a stock piston ls/v with a stock b16a head and if i remember right it put down about 140 whp.
if you gonna use pr4's i advice opening up the valve relieves just in case you want to put bigger cams.
On my opinion using stock pistons is only good if you want to go fi

 

It's definately worth the time and the hassle to upgrade the pistons on the LS/VTEC, it also gives you a chance to replace the relatively weak LS rods.

I've not worked with the stock pistons on an LS/VTEC before, because I couldn't see any reason to.

 

ls rods are the strongest rods that can be found on factory honda motors. also using CTR pistons on a B18 a/B will net you close to 12.2 comp:ratio with a B16 head, good for at leat 160-170- HP depending on set up.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NCHATCH &raquo;</TD></TR><TR><TD CLASS="quote">ls rods are the strongest rods that can be found on factory honda motors. also using CTR pistons on a B18 a/B will net you close to 12.2 comp:ratio with a B16 head, good for at leat 160-170- HP depending on set up.</TD></TR></TABLE>

Maybe I was thinking about something else when I mentioned the rods.

These numbers do look correct though.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NCHATCH &raquo;</TD></TR><TR><TD CLASS="quote">ls rods are the strongest rods that can be found on factory honda motors. </TD></TR></TABLE>

where did you get this info?

 

well, the ls rods are not the strogest b-series...but for na applications is more than enough.
Also pct's in a b18a/b block will yield around 13 compression, not 12.2.
compression height with pct's is higher.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NCHATCH &raquo;</TD></TR><TR><TD CLASS="quote">ls rods are the strongest rods that can be found on factory honda motors. </TD></TR></TABLE>
Something tells me honda wouldn't enginer their weakest motor with their best rods. What about K20's F20's and B18C(1/5) rods?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Cyphear &raquo;</TD></TR><TR><TD CLASS="quote">
Something tells me honda wouldn't enginer their weakest motor with their best rods. What about K20's F20's and B18C(1/5) rods?</TD></TR></TABLE>

Yeah I second that...out of the b series motors I would say that the B18c5 rods MUST be the strongest OEM rods due to the it being the engine with the highest rpm capability. Higher revs lead to higher stresses within the rod when the piston changes directions.

 

The main concern with ls/vtec setups and the rods are the rod bolts. The further you get from center and the faster the rpm(eg the b18a/b crank compared to the b18c or b16) the stronger the centripetal force acting on the rod bolts causeing them to stretch or break. Hence, the b18c and b16 are just fine with the stock rod bolts at higher rpm. The rods themselves are more than enough for an all motor application. Hell, plenty of boosted folks have put down 270+ whp on stock b16, b18a/b, and b18c/5 motors so the rods are just fine.