ToFu-DeLiVeRy

Well i finally finished building my b20vtec setup and i got this serious problem now.... when i got the the car started everything was fine and i thought i have finally finished my build...then when the car got to operating temperature there was a tapping sound or knocking sound coming from the engine....i think the valves are hitting the pistons and i dont know why...im using je pistons designed for a b20 vtec setup which is the b20/b16 pistons with a compression ratio of 11.5...do u guys think i need a valve adjustment or do i have to get the valve reliefs shaved????any help will be really grateful cuz im really frustrated and upset!!!

Combustion Contraption

do a compression test. If youre valves are bent, itll show up there. Check your valve lash.


Or, just pull the ******* head off and check.

ToFu-DeLiVeRy

i checked the head already for bent valves when i had the head off by doing the water leak down test.. nno leaks were found so my valves were ok.

civiccpedx

Maybe you aren't using high enough octane gas. That is a high compression and you may need high octane. Try a octane booster and see if that helps, or just fill er up with premium.

Combustion Contraption

by the way, if valves are hitting pistons at idle, theyre hitting pistons at any RPM. You just cant hear it as well as the rev's increase.

TwoRedEGgs

11.5-1 is fine on pump gas. Just make sure that you have it tunned. What kind of cams are you using in that setup ? You may have to adjsut the valves.

Kamin

you WILL need the valves adjusted, period.

Combustion Contraption

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Kamin &raquo;</TD></TR><TR><TD CLASS="quote">you WILL need the valves adjusted, period. </TD></TR></TABLE>

He's right.

By the way Kamin, hows the car running?

sixtsix mike

is the cam advanced? I read that more than 4 deg. and you would have valve to piston issues....

93H22ACX

well when i used Arias, it made the same sound when it warmend up....dont know why but it sounded like that too...didnt have any problems though.

just do a compression test and valve adjustment.

Combustion Contraption

aaaah, piston slap. The pistons will expand in the bore when they get warmed up. It could be the noise you are hearing is the pistons slapping the sides of the cylinder walls.

Kamin

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LsVtec92Hatch &raquo;</TD></TR><TR><TD CLASS="quote">
By the way Kamin, hows the car running?</TD></TR></TABLE>
HAH
next question

(OBDII ******* sucks, RB is on a pallet waiting to go back in after emissions)

Combustion Contraption

sorry to hear that. Best of luck to you.

Kamin

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LsVtec92Hatch &raquo;</TD></TR><TR><TD CLASS="quote">sorry to hear that. Best of luck to you. </TD></TR></TABLE>
heh it will be back on the road ASAP as soon as i finish school.

ToFu-DeLiVeRy

yea i called the guy at je pistons and he said it sounds like i had piston slap. the guy told me that when i hear something like that its really serious and that i have to take everything out again just to find out whats causing the noise in the motor