fatalman

So my friend just got done putting in his b20 vtec today, and after getting vtec to work, he took it down the street, and once vtec cracked, something bent. Took it home, took the valve cover off (there was smoke coming from the tb and vent) and the rocker arms were loose.

This is the spec on the build.

Stock b20 bottom end
stock head gasket
b16 head milled .040
intake timing advanced a little over 3 degrees for the mill
exhaust timing 5 degrees because of the cams
stage 1 blox's
omni power valve train (high compression valves)
type r intake/tb

so throw some ideas out, could it be clearance issues? or timing?

highperboi

what do you mean when you say the rocker arms were loose??? how was it running before?

fatalman

it was running perfect. it was a fresh b20 vtec build. so it was running fine and driving around fine under vtec, but once we got on it, vtec cracked, then it bogged out and died.

lohatch

b20 valve reliefs + cams + milled head

he clay the engine??

k24a4kid

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lohatch &raquo;</TD></TR><TR><TD CLASS="quote">b20 valve reliefs + cams + milled head

he clay the engine??</TD></TR></TABLE>

i would agreee with that one

fatalman

what would be an ideal solution

k24a4kid

there is a thread on there on how to cut the pistons so the vales clear if your on a budget..

PURPLETERROR aka BIGMATT

stage1cams + milled head + advanced cam timing + stock b2o valve reliefs = bent valves, these threads are getting old. Build it right the first time and you wont have these "mysterious problems

PocketRockets Racing

another infamous "guessing" at clearances.
quessing can be avoided.

measure, measure, measure,........then you know what you have and what you can do with the cams, advanced intake so many degress therefore advance the exhaust so many degress to provide enough valve to valve clearance.

clay the engine so you know what you have. valve to piston clearance and valve to pockets.

UNKNOWN_MEMBER

iTrader: (3)

im guessing the milled head, cams, and cam timing did that.

Mohsin

b16 head milled .040 &lt;&lt; seems like a bit too much milling and didn't help with cam degree adj.

greenbee

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PURPLETERROR aka BIGMATT &raquo;</TD></TR><TR><TD CLASS="quote">stage1cams + milled head + advanced cam timing + stock b2o valve reliefs = bent valves, these threads are getting old. Build it right the first time and you wont have these "mysterious problems</TD></TR></TABLE>

ouch! too bad it's true. topics been covered a billion times.
knowledge is power and in this case money.

fatalman

pulled the head today. most of the valves were bent. one was broken. a whole in the number #1 piston. nasty. time for machine shop and new pistons/valves.

5thgenallmotor

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PocketRockets Racing &raquo;</TD></TR><TR><TD CLASS="quote">another infamous "guessing" at clearances.
quessing can be avoided.

measure, measure, measure,........then you know what you have and what you can do with the cams, advanced intake so many degress therefore advance the exhaust so many degress to provide enough valve to valve clearance.

clay the engine so you know what you have. valve to piston clearance and valve to pockets.</TD></TR></TABLE>

Ouch, I thought people found this out a while ago.... Guess not.

2quikmotorwerks

make sure its done right this time if you need any help hit me up

B20C5 Turbo

Here is just one way to measure V2V clearance:

2quikmotorwerks

GOLDBERG

helpful pic there.. but his problem wasnt v2v clearance it was v2b .. another example of someone cutting a corner on a build and spending alot more than the uncut correct path wouldve costed ..oh well maybe someday theyll learn