I have a 94 gsr, changed the cams to itrs, was in a rush so didnt use new cam seals.
The next day, they were leaking everywhere. I will also note that after doing the change, we mustve messed up on timing so the lowest we had it was +5 advanced. Ran fine, vtec roared, everything was stock sounding etc.

The next day, we took out the cams, put new seals. put everything back in perfect shape. Timing came out perfect this time. The only thing was now its running on 3 cylinders. Cyl #1 wasnt firing so it smelled like fuel. We thought it was the spark because it fell off the shelf onto the floor. Changed spark = nothing, Changed wire = nothing, changed dizzy = nothing. So we checked compression and it was at 0.

The rest were at 220. In the end we thought it was piston rings, but with bad rings, it has to have some compression. When idling it ticks loud.
My question is... Is it just a stuck valve? could the valve be bent from just that?
I would like to know what experiences everyone has had before I take out the motor tomorrow and change pistons and etc.

Thanks in advance and please be quick, we are on a time limit!

 

anyone?

 

im not possitive but im pretty sure fried rings wouldnt give you 0 compression. leakdown test would tell you for sure though.

i would think it would be a stuck or bent valve.

 

i dont have a leakdown test, we are trying to obtain one right now. i think its the valves too, so we hit them to break them free, but no use. still zero. HELPPP!

 

It's gotta be the valves, 110%. Running on nitrous and detonated twice over 4 year period. First, melted a valve. Zero compression, compression gauge didn't even kick at all. Second time, I have compression but really low around 100 psi, bent piston ring lands. You dropped a valve bro. Sorry to hear, good luck.

 

i thought so. is there anyway the piston was damaged? so just repleace head items right? cause i have all that. just checking.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xpsonic &raquo;</TD></TR><TR><TD CLASS="quote">I have a 94 gsr, changed the cams to itrs, was in a rush so didnt use new cam seals.
The next day, they were leaking everywhere. I will also note that after doing the change, we mustve messed up on timing so the lowest we had it was +5 advanced. Ran fine, vtec roared, everything was stock sounding etc.

The next day, we took out the cams, put new seals. put everything back in perfect shape. Timing came out perfect this time. The only thing was now its running on 3 cylinders. Cyl #1 wasnt firing so it smelled like fuel. We thought it was the spark because it fell off the shelf onto the floor. Changed spark = nothing, Changed wire = nothing, changed dizzy = nothing. So we checked compression and it was at 0.

The rest were at 220. In the end we thought it was piston rings, but with bad rings, it has to have some compression. When idling it ticks loud.
My question is... Is it just a stuck valve? could the valve be bent from just that?
I would like to know what experiences everyone has had before I take out the motor tomorrow and change pistons and etc.

Thanks in advance and please be quick, we are on a time limit! </TD></TR></TABLE>

Have you pulled the cam cover to inspect the cam on that cylinder yet? If a valve is bent, the spring will be depressed because the valve is hung open. You will have a significant amount of visable clearance between the cam and the rocker on that cylinder. You will even know if it is the intake or exhaust. If the valve actually broke and 'dropped' you would hear hellacious noise coming from the engine and it would be chewing up the piston and cylinder head. You can also just put compressed air in that cylinder, it's obviously going to have 100% leakdown. If the air comes out the exhaust pipe (go back there and listen) you have a bent exhaust valve. If air is leaking into the intake manifold (pop off the intake ducting to the throttle body and hold the throttle body to the WOT position) you have a bent intake valve. If the air is leaking into the crankcase (remove the oil filler cap and listen for air coming from there) then you have bad rings - or a hole in the piston. Remove the radiator cap, if there are bubbles in the coolant then the head gasket is leaking but I doubt that would cause zero compression.

My question to you would be: what did you do wrong when you were installing the cams? It sounds like you most likely bent an exhaust valve. I say that because if it were an intake valve it would be popping back into the intake when the spark plug fired and probably be quite loud and would assume that you would mention it. Did you bring the engine to TDC #1 before removing the timing belt? At that point the #3 piston would be at BDC and there should have been no way that the piston could have touched the valve. Did the engine or cams spin over when you released the tension on the timing belt?

The other thing that strike me as odd is that you dropped a spark (plug?) from a shelf onto a floor which could have really damaged it unless you have carpet in your garage. Did the ground strap break off in the cylinder? Check the old plug for that or any broken porcelein.

I ask all this because I'd hate to see you put it all back together only to have the same thing happen again. Make sure you check the cam no matter what. You are going to have to pull the cam cover at some point anyway, take a look, make sure no lobes are scored or worn.

-Scott Tucker

 

we have inspected the cam and no valve springs seem to be depressed at all and hung open. the valve did not break for sure because looking into the cylinder and using a magnet, there is nothing besides carbon build up in there. we are actually in the process of finding a leakdown tester, its really hard to find one locally here... dont know why, nobody knows what it is.
so after we get that, i will know where it is leaking from and determine which balve is bent or if the rings are gone, which i doubt it is.
when installing the cams, we messed up on timing, at what was supposed to be stock on the dizzy it was at +20. so the lowest we could adjust it to at the moment was +5, so i had it like that for a day and then we re-installed the cam seals. but the thing is... on that day before we opened it up again, it was running perfectly fine, just the cam seals were leaking, nothing was wrong with compression and it surely was not running on 3 cylinders.
yes the spark plug did drop from the shelf onto the floor, no crack in porcelain, the ground did not break, we thought it wasnt firing because of something that might have happened inside, but obviously after this, that isnt the case.
Let me know if there is anything else i can do prior to the leakdown to determine what is wrong, im pretty sure it is the valves too. I have a full valvetrain setup, so im just gonna throw that into my gsr head.

 

this isn't 100% or anything, just alittle brain blurp thought I had on this subject,

imo 0 compression would be something other than blown rings or just a damaged seal, I had a melted piston all the way down the side of the piston, it still made lik30psi

maybe a valve is just stuck completely open or somethihg? i duno

 

yeah we believe a valve is stuck also, or damaged. so we are going to inspect it a little deeper today. let me know if anyone else knows what we could do to free up the valve or soemthing w/o taking the head off at the moment

 

anymore ideas?

 

i got an idea. you screwed up putting the cam back in, did you like use a screw driver to push in your rockers. i bet you did you dirty dog, i done the same thing

basically, in the cylinder that is 0. pull the valve cover make sure the cam lobes are off (not pushing) on that cylinder, put compressed air through the spark plug hole, listen for air. if u hear the intake hissing, you got a bad in valve, ex bad ex valve, if you can hear it through the oil returns on the head (where the oil drains back to the bottom then you got a bad secondary ring, if none of the above and you hear it hiss through the hole you are sending it then call it yourself lol. and i hope you didnt get the intake and exhaust springs mixed up, that would be stupid man \

if it becomes a valve issue and u didnt pry anything then all u need to do is rotate the crank 45 degrees. smack the valve head where the rocker hits with a hammer and a punch to shock it closed. it may work, had similar happen, i just held the revs at 5 k for 20 seconds. lol

 

nah i didnt use a screw driver to push in the rockers, i used the cam. haha

yeah imma try a leakdown once i find one. thanks for the replies!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xpsonic &raquo;</TD></TR><TR><TD CLASS="quote">nah i didnt use a screw driver to push in the rockers, i used the cam. haha

yeah imma try a leakdown once i find one. thanks for the replies!</TD></TR></TABLE>

Where on the left coast are you that they don't have leakdown testers? You can PM me if you don't want that info public.

 

im in los angeles, i called a bunch of stores and some didnt know what they were and some that carried them didnt have them in stock. so i just ordered one online now.

 

gonna do a leakdown tomorrow. anyone know how to break free the valve if its just stuck? whats the possibility its just stuck anbd not damaged? l

let me know please.

 

oh by the way,
incase noone posted it yet,
cspeed has a nice tutorial on doing a leakdown test.
man I learn so muchfrom these guys/their site
http://www.c-speedracing.com/howto.php

 

yeah i read it over... thanks though!

 

was a bent valve on the exhaust side. gonna put my valvetrain setup in there.. going into the shop tomorrow.

 

kewl