will b16b pistons work in a ls with 404 cams without
valves hitting top of the pistons?

you'll have to check clearances, to this clay the engine.

http://www.c-speedracing.com/howto/claymotor/clay.php

Thanks for the help. I was just wondering if anyone has
done it yet. Well I know what I'm doing this weekend lol. I'll let everyone know how it works out

let us know. i got the same set up so i need to know as well

B16B cams = .447in/.417ex lift
404 cams= .445in/.434ex lift

CTR cams also have much longer duration, and the VTEC valves are 2mm larger than your LS valves. So all in all I'd say there is little to worry about especially on the intake side. Gross lift increase is .5mm on the exhaust side, I doubt it's an issue but you might exercise caution there. Personally I wouldn't use CTR pistons in an LS anyways, for reasons that have been talked about in other threads... but to each his own.

you cant just say that, b16b pistons werent designed to be in a LS block.

Who is the "you", and what is "that" you are referring to?
Obviously they were designed for the B16B specifically, not the LS...however, that can be said of every piston other than stock LS pistons, that hasn't prevented many from successfully doing it. I still don't think CTR's are a good idea so I agree with you, but more because of physics than fitment. Though that brings up another point, the LS rods don't directly fit CTR slugs w/o modding.

what i meant is that you cant just compare valve size and cam specs and say it will be good sonce the blocks are pretty different.

CTR pistons get a bad wrap for LS vtec's but theres a few differences between our motors and LS-vtecs

LS vtecs by nature of the engine have the highest compression ratios anf just about any b series combo out there, LS non vtecs though have larger chamber volumes so the CR isnt so out of control like if you have a GSR head on there. also non vtec motors tend to have less dynamic compression actually making it easier to deal with higher static CR numbers compared to vtec engines with wimpy "idle" lobes. non vtec engines also dont rev super high, usually no more than 8k so the weight isnt as big as a factor comprared to vtec motors.

all that being said, they arent a bad choice for a non vtecer, but JDM ITR pistons are still my all time favorite.

I'm not really referring to compression, I'm sure it's fine with 404's loping away in there. But the reason to use high compression pistons at all is to increase dynamic compression to support large cams like the 404, which need rpms to make power. It's just those particular pistons weigh more, and the stroke is an extra 12mm. So you start with higher reciprocating mass, add much higher piston speeds & not-so-optimal r/s ratio for high rpms, and the force you have working on your internals is pretty wicked. A B18B @ 7250rpm runs the same piston speed of a B16B @ 8400rpm.

You need to re think what you just wrote piston speed is a function of RPM. half way up it is travling at crank speed. all you can change is how long it takes it to get to that speed. And yes reciprocating mass is importation. The piston must stop and start at the top and bottom.

Speed is not simply a "function of rpm". Speed is a measure of distance over time. A shorter stroke crank moves less distance per rpm than a longer one, therefore even at the half-stroke point when piston speed equals crank speed, it is still slower overall.

I am going to have to do some math. I am not real sure what you are saying.

No need to wrack your brain. Just go here and plug in the numbers. Enter the RPM and stroke, then change the stroke to see the difference in piston speed.
http://www.csgnetwork.com/pistonspeedcalc.html

RX3 i think your getting mixed up with the whole R/S ratio thing. were just talking about piston speed here not acceleration.

Sounds like you're right on that, he means acceleration...but, as the case is, both shorter stroke & longer r/s ratio decrease acceleration.

So HAS anyone put together an LS with b16b pistons?

i mean there prolly are some ppl that have, but i've never seen anyone do it...its almost like obvious no-no. This is just what i hear from other people...y do you have to do b16b pistons anywase? is it just cuz the higher compression?