Zinc

Ok, Im almost done w/ the cam swap. I just want to make SURE that I have the timing right on. I know that to do this the #1 piston should be directly on TDC.

Well Im pretty sure it is at that point because I can not (gently) stick a screwdriver into that sparkplug hole. The key on the crank is now at 12 o'clock.

So do I just put my new (Rollmaster Adjustable Double Roller) crank sprocket on so that the dot faces 12 o'clock too? And then put thecam sprocket on and line both of those dots up?

Im just trying to be as safe as possible w/ this install since its my 1st.

THANKS!

Ryan

slyws6

The crank gear is slotted so it can't be off. Just replace it and point the dot on the crank gear straight up then line up the cam gear's dot facing down pointing directly at it. Once you've done that, turn it over by hand one revolution and verify the dots are exactly on.

-Sly

Racer8102

iTrader: (12)

The cam and crank sprockets will only fit one way, cam has a dowell and crank has a keyway, install both, then line up the dots, then put chain on. Easier said than done, probably will have do work at getting the chain on and keeping the dots lined up. Good luck!

Brains

iTrader: (7)

If the keyway on the crank is at 12 o'clock, you are NOT at TDC. It should be at nearly 2 o'clock when the motor is at TDC. The best method is to simply line up the dots on the timing set -- one on the crank sprocket, the other on the cam. The dowel pin on the cam will be at 3 o'clock FYI.

Zinc

OK, Thanks for the help guys!

Zinc

Just to make this clear for a few posts, it doesnt matter if the engine is at TDC, so long as the crank and cam gears are lined up perfect?

Steve Bryant

iTrader: (1)

Zinc,
I understand your nervousness. That's normal!
Get someone to help you for a few hours. Now, what you need to do is to back the crank shaft up (counterclockwise about 30 degrees. Then while someone else turns the crank slowly, put a shaft (like a long blade screwdriver) in the number 1 (driver's side front) spark plug hole just enough to feel the piston rising. As the piston approaches TDC, you may need to pull the probe back so that it doesn't get wedged between the piston and the spark plug hole. What you want to verify is that the probe rises, hesitates and falls as the piston approaches, then reaches TDC and goes past TDC in the #1 cylinder. To do this right, you need someone to help you so you can know in your own mind where that piston is. You probably are exactly right already on the crank sprocket already, but get some help.

Now if the #1 piston is at TDC then yes the dot on the Crankshaft sprocket goes up at the twelve o-clock position.

With the Crank sprocket at the 12:00 position, the Cam Sprocket goes at the 6:00 position (this is what is meant by Dot to Dot). Both dots don't face up as you described.

Now, put the chain on and verify that the dots are together by sighting down in a straight line from the cam centerline to the crank centerline. Turn the crank another revolution and make sure that they line up (you might even do this twice just to be sure).

Then put your push rods in and install the rocker arms (with no spark plugs installed yet). Be sure to pre-lubricate the ends of the push rods and both ends of the rocker arms with some engine assembly lube or even 30 or 40 weight oil. Oil the rocker arm bearings too before installation.

I'm assuming that you have the non-adjustable factory rockers. Torque the rocker arms to 22 ft pounds and turn the crank a half turn three more times and re-torque the rockers to 22 ft pounds each time. This ensures that each rocker arm is being torqued down to 22 ft pounds without the load of a compressed spring. As you turn the crank each half turn, go clockwise and feel and listen for any obstruction. Once you've done the torquing, take a break for a few minutes so you can come back and evaluate things once more from a fresh perspective.

When you come back, rotate the crank back to verify the dot to dot relationship. Then, turn the crank through a few more revolutions until you're satisfied that nothing is touching anything (as in Piston to Valve touching).

Now, pull the fuel pump fuse, get in the vehicle and crank the engine for about 10 seconds three times (let the starter cool for about 30 seconds between each craning). This will let the starter spin the rotating assembly fast enough to do a little pre-oiling and priming of the oil passages. While you do the cranking, you can listen again for any loud metallic sounds (you can expect some noise).

OK, if you're satisfied put the rest of the engine back together (including the fuel pump fuse). Start the engine up and expect a good bit of noise for a couple of minutes during which it will start to quieten down as the lifters pump up again. Check for leaks, drive around a bit and check for leaks again. Enjoy your new cam.

All my best,

Steve

Zinc

THANKS A TON Steve!

Brains

iTrader: (7)

As an aside, if both dots are at the top, that's ok too Since the camshaft rotates at 1/2 the speed of the crankshaft, cyl 1 will be at TDC when the dot on the camshaft is at 0 degrees and again at 180 degrees.

DrkPhx

iTrader: (15)

Just to clarify,the crank sprocket for the Rollmaster double has several slots that allow for adjusting; so there is more than one way to put it on.

Steve Bryant

iTrader: (1)

Brains,
You're exactly right. Also, you're bringing up something that I had never thought about before! Cool

DrkPhx,
I didn't know about the Rollmaster double, but I do know that most aftermarket have three keyways and matching marks like a circle, square and triangle for zero, a retarded and an advanced position.

Zinc,
If you read this, give us a report when you get a chance.

Steve