CAT crank and incorrect keyway positioning?

[psn]

psn, the very first picture, if that is truly at TDC #1, then the key way on the crank appears to be off.

Since it is still a short block, and on a stand (?), go through the process of finding TDC #1 one more time. Do this off the top of the piston #1 (drivers front, right hand piston looking at the front) with a stop. Have the damper, timing cover, and timing tab in place.

Rotate CCW until the piston hits the stop, mark damper where the timing tab is at 0*, then rotate CW until the piston hits the stop, mark damper where the timing tab is at 0*. Find the center between the two marks, remove the piston stop, and rotate so that middle position is at 0* on the timing tab.

Remove damper & timing cover. Now take a piece of string and run it across the front of the engine. From the center of the crankshaft snout to the front center of the #1 piston/cylinder. It should also run straight in line with the crankshaft key way. Hopefully it does.

RemoveBeforeFlight

With the mark I made at the damper, 0 degrees on the timing tab, it does not run a straight line to the center of #1. Rotate CW the original mark on the damper to 0 degrees on the timing tab, and it does.

 

[psn]

How are you finding TDC now?
Mike

With two different dial indicators and a piston stop. Same result every time.

 

[Mike Licht]

if you do the same thing every time you will get the same result. Try this although it is a little oldschool. Put a piece of welding rod (thin) through the spark plug hold and rotate the motor you should be able to feel when the piston stops coming up. Verify it is in the same spot as the system you are using now. No one doubts you but I have never seen a keyway Buick, China or any other that far off before, not saying it cannot happen but it would be a first for me. What does the intake degree to now? what is the cam GROUND on?

 

[psn]

if you do the same thing every time you will get the same result. Try this although it is a little oldschool. Put a piece of welding rod (thin) through the spark plug hold and rotate the motor you should be able to feel when the piston stops coming up. Verify it is in the same spot as the system you are using now. No one doubts you but I have never seen a keyway Buick, China or any other that far off before, not saying it cannot happen but it would be a first for me. What does the intake degree to now? what is the cam GROUND on?

Sure, I can do that.

Intake centerline degrees to 109 with the timing set installed the way it is in the picture. Sorry, english is not my native language, but by "what is the cam ground on" you mean the intake centerline on the cam card? If so, cam card says intake centerline @ 109 degrees.

 

[ek02]

I looked at a crank today and the key way should be directly opposite from the center of the front counterweight. It should also line up with the front crankpin. If your's does not, it is the keyway that is off. Any good crankshaft grinder can fix it.

 

[psn]

I looked at a crank today and the key way should be directly opposite from the center of the front counterweight. It should also line up with the front crankpin. If your's does not, it is the keyway that is off. Any good crankshaft grinder can fix it.

Thanks for the info, I will check that.

 

[Mike Licht]

on your cam card what does it say for lobe seperation

 

[psn]

on your cam card what does it say for lobe seperation

113

 

[84BuickGNYorkPA]

Just curious, why don't you have the crank gear straight up at zero degrees? I understand what Paul is saying but, why throw that crank gear on at the wrong slot? I try to keep things simple, my recommendation would be.
1) Rotate cam until dot is straight down on the cam, verify both valves are closed, or if the heads are not on, that #1 cam lobes are not pointed up toward the top of #1 bore.
2) Unbolt the cam gear from the cam.
3) pull the crank gear off the crank.
4) rotate the crank to TDC use a stop, go both directions, split the difference or use a indicator and stop at the most plus reading.
5) put the crank gear back on with the double dots straight up, use what ever slot on lower gear that you need to do this (your picture shows that they are at 10 o'clock)
5) put the chain back on the crank gear and hold the cam gear up to the cam.
6) rotate the chain link as necc to get the mark "0" straight down on the center line of the cam and crank.
7) bolt the cam gear back on, at this point both valves should be closed, and all the dots line up, and the crank should be at TDC
8) verify that you are on the compression stroke by rotating the crank one revolution, the cam should show that the valves on #1 cylinder are open
9) rotate the crank one more revolution, the cam should show that the valves are closed.
Now how does it all look? Anything like this, minus the idler if your running a double chain?
My crank gear also came with multiple key slots like yours and the key is at 1 to 2 o'clock on mine... factory crank. Your key does look more like a 1 o'clock position...
Hope this was of some help to someone, good luck !

Chuck

 

[cruzn57]

is the above pic your motor?
it appears your using a roller chain with the stock type tensioner.
a big no no! it will destroy/ eat up the tensioner in a very short time,
leaving alot of trash in the pan, to be sucked up into the oil pickup.

 

[84BuickGNYorkPA]

That was 5 yrs ago, it actually lived 2yrs in there until I put the new motor in, which does not have the tensioner.

Chuck

 

[psn]

I looked at a crank today and the key way should be directly opposite from the center of the front counterweight. It should also line up with the front crankpin. If your's does not, it is the keyway that is off. Any good crankshaft grinder can fix it.

A quick glance and it does seem to be a bit off from the center of the counterweight.

 

[psn]

Just curious, why don't you have the crank gear straight up at zero degrees? I understand what Paul is saying but, why throw that crank gear on at the wrong slot?

That is to show the setup that gives me intake centerline @109 deg. Put the key in any other slot and it's off

 

[dr_frankenstein]

so the results are?

 

[psn]

so the results are?

~11.5 degrees rotated reluctor ring on the balancer. If it doesn't run I'll forget the car in a barn for five years and try again.