Troux

iTrader: (4)

I'm trying to install a Comp Cams adjustable timing set on my stock heads/cam LS2. I have the engine on a stand, so you think it'd be easy, but I'm about ready to throw the engine in the river. I'm trying to line the dots up, but every time I try to get the crank dot to 12:00, it jumps right over it, as the compression makes it difficult to turn, then easy. I've tried going back and forth several times and can't get it there.

Then the camshaft is supposed to be lined up at the 6:00 position, but I can't turn it by hand (as the ls1howto guide recommends). It physically can't be turned by hand. The only way I can manage to turn it is by hooking up the timing chain when it's hooked up, but now that they aren't aligned, I can't get the chain on with all 3 cam bolts in. How the hell is everyone installing cams and timing sets?

If anyone in the Tampa area thinks they can knock this part out (just the timing set and chain install) in under and hour, I'll throw ya $30. Thanks.

LS1MCSS

iTrader: (18)

Pull the spark plugs out to make the crank easier to turn. The cam should spin freely, if the pushrods are out of the engine. If it doesn't, something isn't right.

deuce_454

step 1. remove plugs............
step 2. loosen rockers.............
then carry on as before

deuce_454

just beat me 2 it

vettenuts

iTrader: (4)

How are you actually doing this? If its an adjustable set, there should be no valve train in the motor at all. If the cam doesn't spin freely with the pushrods out then you better check the cam as it may be cut wrong and interfering with the retainer plate.

Troux

iTrader: (4)

The valvetrain is still in the car. I guess that's my issue with the cam, since all of the writeups I've been reading (including the Comp Cams instructions) are assuming I'm starting with an emptied-out engine.

Troux

iTrader: (4)

Ok, now I'm completely lost. There are points in the crank rotation where it won't budge at all anymore. Is it possible the pistons are running into the valves? Is this install impossible to do without removing the heads? Also, isn't it possible to have the cam 180 degrees off, even if they are lined up dot-to-dot? How do I prevent this?

R1ch

iTrader: (4)

The reluctor wheel will only go on one way because there is a dowel pin on the cam itself. When I did mine we had no spark plugs in the motor and the valve covers were off with no rockers on or pushrods.

Troux

iTrader: (4)

Right, but for every cam rotation, there are 2 crank rotations, so is there a danger of the cam being dot-to-dot on the wrong crank rotation?

LS1MCSS

iTrader: (18)

If the bottom gear has dots for retarding or advancing the timing, those aren't the dots you line up when you put the chain on. Those are for getting the gear in the correct keyway. Look for another dot that doesn't have a number next to it. It can be confusing if it's your first time.

NOBR8KSS

iTrader: (12)

Troux,
Even though the crankshaft turns over twice for one cam revolution, it is repeating the same cycle of piston movements each time. All it does is move the pistons. All the valve timing is done by the cam...so as long as the crank and cam gears are installed properly on the crank and cam snouts, and lined up dot to dot, you should be fine. If that is done correctly, the only thing that would cause piston to valve contact is a cam that has too much lift, too much duration, or a combination of both.

Comp Cams adjustable chain, there are TWO "0" marks on the crank gear (if I remember correctly)...be VERY careful that you are using the right one!!!!! They are in different locations and they are easy to get mixed up....reread the directions very carefully and make sure you've got it right.
JC

Troux

iTrader: (4)

There are actually 3 marks on the Comp Cams crank sprocket (square, triangle, circle). I'm using the standard, recommended one (circle).

Skinny

iTrader: (11)

If the rockers are off (which they should be) then all of the valves should be fully closed and never open, thus there should be no interference with the pistons/valves. If you still have the rockers on the heads, then remove them before you go any further. With that done and the spark plugs pulled, you should be able to freely spin the crankshaft and the camshaft. The cam sprocket will only fit on the cam one way, so as long as you have the dots lined up, you cannot have the cam 180* off.

eallanboggs

iTrader: (1)

Some people question why I keep telling the inexperienced guys to put it DOT to DOT BEFORE they start taking things apart. This guy is a perfect example of why it should be done the way I suggest. Sure, some people can do this stuff in their sleep while others can NOT do it after reading everything they can get their hands on. Do you know the 4 stroke cycle? Do you know the function of the crank and cam? The cam is the brains and the crank is the low paid blue collar worker. Do you understand this relationship? If you don't know how this relationship works you should PAY someone to do this for you. It is a MUST that you have a grasp on the 4 stroke cycle unless you want to depend on Lady Luck to get it right. With the cost of engine parts I doubt you want to go that route. There are whole lot of guys on this site that would tell you "do this, this and this"(many in your area) if they were standing over your shoulder and then "Turn the key". I admire you for trying, but if you're in over your head you have to call the Coast Guard. You are making some basic mistakes and your inexperience level is such that you can't even ask the right question that will lead you down the yellow brick road. So sad! I hope you get this thing going.

Troux

iTrader: (4)

^I had it lined up "about" dot-to-dot before taking it apart, but the problem was that I still couldn't get it to stop at 12:00, and still couldn't after taking out the spark plugs, after trying several times. I figured I could just leave them in the position they were in and get the others on the same way (knowing where the dots were), but the timing set I have made that pretty much impossible, which forced me to keep turning them individually.

I am at the point now where they are probably lined up correctly, but I still can't tell because I can't get them to stop in the right position. Either way, my crank bolt broke off in the snout, so I'm going to have to somehow get the engine to a shop that can fix my 2 major problems. Would have much rather just paid someone to do it if I knew it was going to be such a pain in the ***.

Sort of lined up. Notice each is just past its proper location.



Head of crank bolt sheared off. FML.

R1ch

iTrader: (4)

I had a GM master tech that did his own H/C himself helping me so this was a point made at the beginning. lol

Notmyvette

iTrader: (1)

Another thing is Cam TIMING...you can have a cam with a mild lift and mild duration but if it was timed wrong (especially on the verge of p-to-v clearance already) they're going to hit if the valves open too early or too late.



And I was gonna say the same to pull the plugs and valvetrain....about the bolt in the snout, did you try using vice grips or like a monkey wrench on that stud and just twist it out? Or also could get another nut tightened against that nut and get a wrench on the rear nut and loosen it and should be enough to get the stud out....

Troux

iTrader: (4)

That's what I was saying (Re: Timing). I didn't know if it was an interference motor or not, which is why I asked if there were a chance that the pistons and valves could make contact if I had the cam and crank sprocket at arbitrary points in their rotation.

As for the bolt in the snout, it took a TON of force to break the head off the bolt. I think (wishful as it may be) the crank threads are alright, or, worst case, reparable, but I'm gonna see if I can get it lifted to a local shop to finish the job right.

vsocks1

iTrader: (6)

Were you using the pulley install tool to turn the crank and the bolt head broke off?

eallanboggs

iTrader: (1)

You've got the rockers off and pushrods out, right? If you do and the chain is OFF the crank and cam should NOT want to go to any certain position or past a certain point in their rotation for that matter. If they do there is a problem. With the chain off the cam and crank don't even know each other exists. It's only when the chain is installed that the chain marries the cam and crank. This is an arranged marriage. The chain is the parent of both of the children and the chain forces them into this relationship.