Can the stock ls pistons be used for turbo ls/vtec? Will this setup be a bad idea if it will work? B18a block with gsr head.

 

yes you can use them, but if the motor is apart why not upgrade

 

Aren't the LS pistons valve relief cuts to small for the vtec valves? Just wondering because i plan on running a turbo ls vtec myself and correct me if i'm wrong but I was going to use (dished) forged 9.0:1 pistons for a gsr or b16 on forged eagle rods. will this setup work with 93 octane pump gas? let me know if you recommend useing LS pistons and why.

 

you need VTEC pistons because of the largers valve reliefs.
vtec intake valves are 33mm
non-vtec intake valves are 31mm

the exhaust valve are 28mm for both vtec and non-vtec

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony413 &raquo;</TD></TR><TR><TD CLASS="quote">you need VTEC pistons because of the largers valve reliefs.
vtec intake valves are 33mm
non-vtec intake valves are 31mm

the exhaust valve are 28mm for both vtec and non-vtec </TD></TR></TABLE>

correct, i found this out the hard way with ls pistons in my b16a block with type r cams we grinded down the valve reliefs and no more problem, i believe b16a cams will be ok but its not worth the hassle, get vtec pistons, you can find the stock ones on ebay for like $75-100

 

So you are saying any forged 9.0:1 piston will work for my setup. Running a GSR head leftover brand new omni power valvetrain b18a crank etc. aftermarket main girdle with arp gsr main bolts gsr windage tray and pan. gsr cams or blox type b's (just wondering do the pistons need to be dished or can they just be 9.0:1 compression to run 10-15 psi on 93 octane pump gas

 

So I just want to make sure I am hearing this correct because I am going to be doing the same thing. When I am doing my LS/Vtec(B18b block/JDMB16a head) build with Wiseco pistons and Eagle rods, I of course buy the rods for a B18B and then buy the pistons for a GSR? Thanks.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 97_coupe &raquo;</TD></TR><TR><TD CLASS="quote">So I just want to make sure I am hearing this correct because I am going to be doing the same thing. When I am doing my LS/Vtec(B18b block/JDMB16a head) build with Wiseco pistons and Eagle rods, I of course buy the rods for a B18B and then buy the pistons for a GSR? Thanks.</TD></TR></TABLE>

LS/Vtec =
B18A or B18B block
B16 or B18C pistons
B18A or B18B rods

your rods DEPEND on what crank you use for the most part if you use a GSR ot TYPE-R crank get those rods. if you use a NON-vtec crank get those rods

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ys1civicsi &raquo;</TD></TR><TR><TD CLASS="quote"> (just wondering do the pistons need to be dished or can they just be 9.0:1 compression to run 10-15 psi on 93 octane pump gas</TD></TR></TABLE>

good tuning accounts for keeping the motor safe.

dish'ing the pistons is just a common style of piston in order to lower compression ratio. i have seen flat top 9:1 pistons but not for a honda. also bore size can change the comp. ratios that are availble to buy.

 

Well, with an LS/vtec the stock LS pistons will clear B16cams/head without modification. I've built several that way with no problems or contact whatsoever.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RC000E &raquo;</TD></TR><TR><TD CLASS="quote">Well, with an LS/vtec the stock LS pistons will clear B16cams/head without modification. I've built several that way with no problems or contact whatsoever.</TD></TR></TABLE>

the cams and head arent the problem its the valves circum. area b16= 33mm and b18b= 31mm.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony413 &raquo;</TD></TR><TR><TD CLASS="quote">

the cams and head arent the problem its the valves circum. area b16= 33mm and b18b= 31mm. </TD></TR></TABLE>

but if the cams are so tine the valves dont come close the piston none of that matters, RC000E is correct should be correct on this one. what i was saying is with type R cams or larger is where you run into the problem...

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 97_coupe &raquo;</TD></TR><TR><TD CLASS="quote">So I just want to make sure I am hearing this correct because I am going to be doing the same thing. When I am doing my LS/Vtec(B18b block/JDMB16a head) build with Wiseco pistons and Eagle rods, I of course buy the rods for a B18B and then buy the pistons for a GSR? Thanks.</TD></TR></TABLE>

yes but get your pistons a slightly lower compression than you want cause its gonna go up a bit with the GSR head and you k now your gonna hve the block decked and the head resurfaced too...

 

FYI: Wiseco uses the same part numbers for B16A/B, B18A/B, and B18C pistons. They use the same forgings for all of them, but give different CR ratings for the different head/block combos. I'm not sure if this is true for other piston manufacturers as well, but if you're getting Wiseco's, you don't reall need to worry about whether it's a VTEC piston or not, just pay attention to what CR it yields with your particular head/block combo.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by inspyral &raquo;</TD></TR><TR><TD CLASS="quote">FYI: Wiseco uses the same part numbers for B16A/B, B18A/B, and B18C pistons. They use the same forgings for all of them, but give different CR ratings for the different head/block combos. I'm not sure if this is true for other piston manufacturers as well, but if you're getting Wiseco's, you don't reall need to worry about whether it's a VTEC piston or not, just pay attention to what CR it yields with your particular head/block combo. </TD></TR></TABLE>

intresting, they probably just cut the vtec size valve relief into all there pistons, thats not a bad way to save some production cost... speaking of valve reliefs and all what do the people with oversize valves do? custom pistons? or do they just grind down there pistons like did???

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blinx9900 &raquo;</TD></TR><TR><TD CLASS="quote">

intresting, they probably just cut the vtec size valve relief into all there pistons, thats not a bad way to save some production cost... speaking of valve reliefs and all what do the people with oversize valves do? custom pistons? or do they just grind down there pistons like did???</TD></TR></TABLE>
Most aftermarket forged pistons have oversized valve reliefs. Some go all the way to the outside edge of the piston, so I'd assume it'd be difficult to "outgrow" them without having the valves hit either each other or the cylinder wall.

 

I ran my stock lsvtec with type r cams for about a year with no problems at all. I guess I got lucky

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony413 &raquo;</TD></TR><TR><TD CLASS="quote">

the cams and head arent the problem its the valves circum. area b16= 33mm and b18b= 31mm. </TD></TR></TABLE>

My point was to say that with the specific combination of B16 head/cams, I've run unmodified LS pistons on several builds. I understand the valve size differences, but my point is, with the lift/duration of the B16 cams, there is no interference.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by champLSinteg &raquo;</TD></TR><TR><TD CLASS="quote">I ran my stock lsvtec with type r cams for about a year with no problems at all. I guess I got lucky </TD></TR></TABLE>

the questions is did you ever take off the head and inspect the pistons for contact? i still made 317whp with 4 bent valves and a dent in all my vavle releifs, we pulled the head to do guide seals and thats when we saw the damage, if we didnt pull the head we would have never known.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by inspyral &raquo;</TD></TR><TR><TD CLASS="quote">
Most aftermarket forged pistons have oversized valve reliefs. Some go all the way to the outside edge of the piston, so I'd assume it'd be difficult to "outgrow" them without having the valves hit either each other or the cylinder wall.
</TD></TR></TABLE>

can you get intake valves from both vtec and non vtec engines an sit them in the relief of the pistons

 

Just clay the cylinders upon assembly & all your questions will be answered.

 

thanks guys you have really helped me out with my dilema I never though after searching and responding to a 2 year old post that so many responses would be made to it. I am going to use 9.0:1 wiseco pistons for my build along with eagle h-beams thanks a lot

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blinx9900 &raquo;</TD></TR><TR><TD CLASS="quote">
the questions is did you ever take off the head and inspect the pistons for contact? i still made 317whp with 4 bent valves and a dent in all my vavle releifs, we pulled the head to do guide seals and thats when we saw the damage, if we didnt pull the head we would have never known.</TD></TR></TABLE>
When I built my new block I tore down the LS block and I did not notice any contact on the pistons and no valves were bent. The valves were taken out and check when I installed new valvesprings. All I saw were broken ringlands! The same head is on my current block. The motor was revved to 8500 often...I am surprise the rod bolts never let go...good thing they didnt!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Running925 &raquo;</TD></TR><TR><TD CLASS="quote">Just clay the cylinders upon assembly & all your questions will be answered. </TD></TR></TABLE>

i love how people online say things like just a hop skip and a jump away, thats a major pita to do...

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by champLSinteg &raquo;</TD></TR><TR><TD CLASS="quote">
When I built my new block I tore down the LS block and I did not notice any contact on the pistons and no valves were bent. The valves were taken out and check when I installed new valvesprings. All I saw were broken ringlands! The same head is on my current block. The motor was revved to 8500 often...I am surprise the rod bolts never let go...good thing they didnt!</TD></TR></TABLE>

intresting, well thats cool i guess, i was using ls pistons in a b16a block perhaps that explains our differences...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blinx9900 &raquo;</TD></TR><TR><TD CLASS="quote">

i love how people online say things like just a hop skip and a jump away, thats a major pita to do...</TD></TR></TABLE>

The even funnier part is, that I've rebuilt two guys motors who clayed them prior to assembly, saw no problem, then upon running them they had contact.

Too many people clay their motor, then forget to lock the rockers in the clay'd cylinder into vtec. DON'T forget to do it ANYONE that clays the motor.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RC000E &raquo;</TD></TR><TR><TD CLASS="quote">

The even funnier part is, that I've rebuilt two guys motors who clayed them prior to assembly, saw no problem, then upon running them they had contact.

Too many people clay their motor, then forget to lock the rockers in the clay'd cylinder into vtec. DON'T forget to do it ANYONE that clays the motor.</TD></TR></TABLE>

oh man, that sounds like an upsetting situation!! all that work for nothing.