black00WS6

Paul,

Paceparts has valves for about 15 each, and metro has them for about 20 each(not including the 10% off). Hopefully bent valves arent the case though.

rom3

Ok, starting to get this now. Sorry for posting misinformation above (i've edited out to avoid confusion).

However, is the right question to ask really "Is the crank 360 degrees out of phase?". Ie. #1 was a TDC on the wrong stroke and now keeping the valves open on the compression stroke?

Scalpel

iTrader: (4)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Ryoga:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by rom3:
<strong>Since the crank rotates twice for each rotation of the cam, it is possible to install "dot to dot" out of phase. The dots must line up when #1 is at TDC of the compression stroke, just about to fire. This was the point of the earlier posts regarding making sure both valves on #1 were closed and #1 piston was at the top of it's travel. How was the dot to dot install done?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">We turned the crank until the dot was at the 6 o'clock position and then took the chain off and turned the crank until it was at the 12 o'clock position. Put the chain back on and buttoned it up.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">This is what it was supposed to look like BEFORE you took the chain off:

http://www.fbodylinks.com/tech/valvesprings.htm

Dave Carney

I bet Nick at ARE has a buttload of used valves for next to nothing....

98blackSS

ok ss00blue got me thinking right again.. whew.. I'll need a vacation after this thread is over!

<small>[ June 20, 2002, 11:34 AM: Message edited by: 98blackSS ]</small>

black00WS6

he adjusted the 2 gears so the dots lined up, and both the valves were closed. So that is TDC with #1 firing?? right?!?!?

paul, give me a call at work..760-8189

SS00Blue

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by rom3:
<strong>Since the crank rotates twice for each rotation of the cam, it is possible to install "dot to dot" out of phase.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">NO! NO! NO! THE CRANK ROTATES TWICE FOR EACH CAM ROTATION! THE CRANK DOT PASSES 12 O'CLOCK TWICE BUT THE CAM DOT ONLY PASSES 6 O'CLOCK ONCE. YOU CANNOT HAVE THE CAM AND CRANK GEARS IN THE POSITION SHOWN BY THIS PICTURE ( http://www.ls1info.com/article.php?sid=192 ) UNLESS YOU ARE ON #1 TDC!!!!!!!!!

Please stop posting if you don't know what you're talking about. YOU'RE NOT HELPING!

Whew. Glad I got THAT off my chest. Sorry to all about the passionate rhetoric.

As to the valve situation, the stock valves are cheap. The previous suggestion to call a head shop for used valves is a great one! Valves, bolts, and a set of gaskets might get it done for maybe a C-note if you replace the abused valves yourself.

SC

Ryoga: I am truly sorry that this escalated to a difficult install. Please don't let it discourage you from future mods. EVERYONE on this board, that has done their own mods, has made mistakes. But they are only worthwhile if they teach us something. It all just one big school, but recess is almost here for you, don't pack it in now!

<small>[ June 20, 2002, 12:44 PM: Message edited by: SS00Blue ]</small>

Jadeeglide1550

I hope I can help you out, or put you on the right track. Having worked on engines for years, you see some strange things.
First off, you need four basic things for the engine to run.... spark at the right time, fuel at the right time, air at the right time (vacuum), and compression. I had a problem similar to yours a few years back and called Crane Cams. They told me to check spark, fuel pressure, and compression. I had spark, I had the fuel pressure, but did not have the compression. I knew the cam was in correct as I had used a degree wheel to get it right, but what I found was that the valves were not seating as the push rods were too short and the rocker arms were binding when adjusted. I had changed to screw in studs ( this was an earlier generation motor) and the machine shop had gotten to happy with the amount of material they had removed. Anyway, after getting the rocker arms sorted out, the engine started up like a champ.
I would suggest you check the fuel pressure on the fuel rail, do a compression check. The compression will also be low if the cam was installed wrong, off a tooth, 180 degress off, etc. Checking number 1 will tell you a lot. If you have good compression then you can go on to see if the spark is timed right. Pull a plug, connect it to a plug wire and use an wire with a large aligator clip to ground the outside of the engine to the block. Crank it over and see if you are getting a nice blue spark jumping the gap. Use a timing light and mark the balancer at TDC to check that the spark is firing at the right time. You can put your finger over the number 1 plug hole (with the plug out naturally) and pull the engine over by hand. You are at TDC on the ignition stroke if it blows your finger away, on the exhaust stroke you will feel nothing.
I would also recommend looking at the valve train with the valve covers off and someone cranking the engine to see that the valves were opening and closing properly. With the stock rocker arms and a cam change, you might have a problem as the base circles on these cams is smaller than on the stock cam. Using the Crane Roller Rockers with the adjustable nuts allows you to set the rockers up so that at least you know they are closing and opening the valves properly. If the lifters have not bled down they also would tend to keep a valve from closing and this would show up on a compression check, as will a broken spring, since the valve will not be pulled closed.
Lots of strange things happen, and as painful as it is, sometimes you have to go back to square one and start over, evaluating the valve train movement.
Hope this helps and you get that LS-1 Running.

black00WS6

but what if all the valves are the same height?

98blackSS

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by black00WS6:
<strong>but what if all the valves are the same height?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Someone correct me if I'm wrong, but I thought this wasn't a very good indicator of bent valve checking. I thought I saw someone post once that everything can look fine but a valve can be bent just enough to where it won't seat properly even though externally the height looks ok.

Just think Ryoga, at least one day you'll be able to sit back and laugh about all this.. one day that is.. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

black00WS6

if we were to hook an air compressor line up to it (like when we change the valve springs), if a valve was bent would we be able to hear air coming out of the top??

XtraCajunSS

iTrader: (2)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by black00WS6:
<strong>if we were to hook an air compressor line up to it (like when we change the valve springs), if a valve was bent would we be able to hear air coming out of the top??</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Yes, that is the best test. If air comes out of the intake then the intake valve is bent. If air comes out of the exhaust port then the exhaust valve is bent.

Easy test.

Shane

98blackSS

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by black00WS6:
<strong>if we were to hook an air compressor line up to it (like when we change the valve springs), if a valve was bent would we be able to hear air coming out of the top??</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Ah, good idea.. should be able to narrow it down to how many valves will need changing even before the heads come off. Hopefully, not many..

Jadeeglide1550

What SS says about the base circle being smaller is true... but the problem comes when torqueing down other than stock rockers... in this case you can get into other areas which cause the valve to be open... even to the point that you can in and extreme case snap off the rocker shaft itself.
I would say... go to square one and check... before getting paranoid and pulling heads..... check compression etc.... if worst comes to worst..... that he wiped the cam... heaven forbid.. a valve would never close... but I would think that unlikely with the roller cam/lifters used in the LS-1.... Usually it is the simple stuff that escapes you and caused the problem... I had it once that I went nuts and it was not until I pulled the heads that I found that one of the springs had broken (I was too lazy then to test the compression...) If he put the cam in wrong and corrected it later, he may have bent some valves.... but I hope he pulled it around by hand first to check no binding... checked there was no coil binding... and the hundred other little checks one does before spinning the motor with the starter.
I wish him luck and hope he gets er running...... ASAP.... he sounds stressed to the max...

Tin Indian

I may have missed something in here.

You said you were positive the dots lined up (crank dot at 12 and cam dot at 6) when you first installed the timing gear set.

How did it ever get 3 teeth off afterwards ?????

I am betting you have NO valves bent. I am also betting you DO HAVE bent pushrods. The pushrods will bend prior to the valve stems if the valves are in contact with the pistons. The valves may have put a nick on the top of the pistons, but this is no big deal as long as the valve is not bent.

1. Correctly install the cam / timing set

2. Replace any bent pushrods (roll them on a piece of glass)

3. Do a leakdown test (or at least a compression check on the cylinders that the bent pushrods came out of) No real need to check cylinders that had no bent pushrods unless you have time to spare.

Good luck,
Ron

<small>[ June 20, 2002, 05:44 PM: Message edited by: Kimchee and Rice ]</small>

Tin Indian

BTW, same thing happened to me a long time ago with a Turbo Buick engine and an [adjustable] timing set.

Bent 4 hardened pushrods into an S shape when the starter turned the engine over during the "attempted" engine start. Engine would not run (only pop)

NO bent valves

Again...... How did it get from the dots lined up to 3 teeth off?

98blackSS

He said "at least" three teeth off...

black00WS6

well I'm the one who swapped the cams. We didnt have a flash light so here is what happened. I made sure the cam gear was at 6 o'clock, took it out, slid the new cam in, and installed it with the dot at 6 o'clock as well. We're assuming that somewhere in there, the crank got turned and with no light, we couldnt tell. <note to self, ALWAYS use a flashlight from now on>

we just dont know how the crank one turned <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

Tin Indian

I can understand that.... Well, from now on, do your installs in the daylight or in a well lit garage. The dot on the crank gear is VERY hard to see. Needs to be marked with white paint.

Anyway, I still bet you only have bent pushrods and not valves. Do what I said in my previous 2 posts.

Good Luck, <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Ron,

black00WS6

they were brand new hardened pushrods, they would bend that easy?!?!