CAT crank and incorrect keyway positioning?

psn

Member
Joined
Feb 8, 2009
I have an unexpected problem with the crank that I noticed when trying to degree the cam. I kept getting very strange ICL numbers and at first it was purely because I did not know how to set up the timing chain and gears (TA Perf. 9 key timing set).

But when I got the instructions for the timing set I noticed that when I bring #1 cylinder to TDC the timing marks do not line up and crank key is not pointing to 2:00 o'clock. At TDC it is at 1:00 o'clock. In both of the pictures #1 is at TDC, and you can see how off it is.

Has anyone experienced anything like this? I wish it would be just a user error, since this is my first time building a turbo Buick engine.

Short block includes 109 block, CAT stock stroke crank, TA Perf. balancer, K1 rods, JE pistons. Comp 214/210 roller.

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did you verify true tdc with a piston stop and rotation of crank clockwise and then counterclockwise , marking the points and then find center of those points
 
did you verify true tdc with a piston stop and rotation of crank clockwise and then counterclockwise , marking the points and then find center of those points

About 105 times. When timing marks line up, piston is visibly below TDC
 
Like I told you, the crank gear is NOT in the correct slot, which is why the key is at 1:00 o'clock, not 2:00 where it should be to have the cam straight up at TDC.:(

I know the marks on the Rollmaster timing set can be confusing, but the crank key needs to be on one dot at 2:00, the other dot will line up with the dot on the cam gear.

Now if you set it this way and number piston is NOT at TDC, then you could have the first ever crank keyway issue.

I "asume" you, or your friend, do know this Buick V-6 has number 1 cylinder at the front of the block on the driver's side?
 
crank gear has no effect on tdc when balancer is on
his claim is with balancer on and rotated to zero on timing indicator that piston has noticably moved down into cylinder from TDC
the crank gear could be in his trunk and it wouldnt change that relationship

this would be either balancer slot or crank slot , again if he is using #1 and not #2 piston

with #1 at tdc the crank slot should point directly to the center of the #1 bore
if it does not the crank slot is off , fix is weld it closed and recut the keyway or see if you can find an offset key but if it is 12degrees its too far for an offset key
 
Like I told you, the crank gear is NOT in the correct slot, which is why the key is at 1:00 o'clock, not 2:00 where it should be to have the cam straight up at TDC.:(

I know the marks on the Rollmaster timing set can be confusing, but the crank key needs to be on one dot at 2:00, the other dot will line up with the dot on the cam gear.

Now if you set it this way and number piston is NOT at TDC, then you could have the first ever crank keyway issue.

I "asume" you, or your friend, do know this Buick V-6 has number 1 cylinder at the front of the block on the driver's side?

This is a direct quote from your reply, when I sent you the exact same picture included in the first post.

"The cam is set properly. The crank key is in the proper slot".

And again, this is not a Rollmaster timing set, you should know better, because you're the one who sold it to me.

And yes, I know where #1 is.
 
with #1 at tdc the crank slot should point directly to the center of the #1 bore
if it does not the crank slot is off , fix is weld it closed and recut the keyway or see if you can find an offset key but if it is 12degrees its too far for an offset key

Correct me if I'm wrong, but wouldn't the crank sensor be the only thing affected with incorrect key positioning, since the windows on the trigger wheel are not in a position they should be? So if I was to rotate the trigger wheel ~11 degrees, or whatever it is off, then I should be fine. I would just have to fabricate a new timing pointer.

Assuming the wheel would come off the balancer and go back nicely.
 
you cold reindex (scribe ) a new balancer pointer mark and move the reluctor ring and index it 12 degrees off but that still leaves you trying to get the valve timing correct
 
on a longshot ive never tried this so i can't say if its even possible but...
is it possible you have the #1 rod attached to the #2 crank journal
 
you cold reindex (scribe ) a new balancer pointer mark and move the reluctor ring and index it 12 degrees off but that still leaves you trying to get the valve timing correct

Is the reluctor ring just pressed in the balancer? Valve timing is set according to cam card specs. Intake center line is at 109 degrees. At least I got three back to back 109s. All I need is key in the proper crank gear slot, cam gear at 6:00 o'clock and true #1 TDC to get it right, right?
 
on a longshot ive never tried this so i can't say if its even possible but...
is it possible you have the #1 rod attached to the #2 crank journal

I would say it is not possible, but now that you mentioned it, I can't be sure of anything right now.
 
If the crank key is at 2 oclock and #1 piston is at TDC, the crank is fine. The damper could be the wrong one. If the key is at 1 oclock with the piston at TDC, the keyway is off. Fix the crank if that is the case. Juggling the trigger wheel and cam timing could cause you problems.
 
crank gear has no effect on tdc when balancer is on
his claim is with balancer on and rotated to zero on timing indicator that piston has noticably moved down into cylinder from TDC
the crank gear could be in his trunk and it wouldnt change that relationship..........

I know you are correct Paul, but he has the piston down in the hole at TDC, and never said that it was checked with a cover and balancer at zero.

From the pic, the crank gear is NOT in the proper slot for straight up at TDC.

I have a Rollmaster crank gear here on my desk to verify it is NOT installed in the proper gear keyway as I see in that view.

After a few hundred aftermarket cranks we, and others, have installed never seen or heard of a keyway in the wrong place. But know of many "issues" with Rollmaster installations info which has 9 different positions! :)

Pirkka, if you have a used timing set off your engine old engine, try that to see if the cam lines up properly?
 
Ignore all balancer and timing marks and find true tdc. Then determine if the damper, crank key location and timing tab are wrong. I've had dampers with false numbers on them. I just scribed my own zero. The ring on the balancer can be adjusted if needed or the timing can be offset through the ecu unless it's way off. I find it unlikely the crank/cam gears are a possible problem. Degreeing process will show that. The crank gear appears to be in the wrong slot in the picture.
 
I know you are correct Paul, but he has the piston down in the hole at TDC, and never said that it was checked with a cover and balancer at zero.

From the pic, the crank gear is NOT in the proper slot for straight up at TDC.

I have a Rollmaster crank gear here on my desk to verify it is NOT installed in the proper gear keyway as I see in that view.

After a few hundred aftermarket cranks we, and others, have installed never seen or heard of a keyway in the wrong place. But know of many "issues" with Rollmaster installations info which has 9 different positions! :)

Pirkka, if you have a used timing set off your engine old engine, try that to see if the cam lines up properly?

I can't see how I would be able to install the crank gear correctly, when the key is not at the right position, when #1 is at TDC? I don't have the stock timing set anymore, it was missing teeth and was badly worn, so I threw it away.
 
Ignore all balancer and timing marks and find true tdc. Then determine if the damper, crank key location and timing tab are wrong. I've had dampers with false numbers on them. I just scribed my own zero. The ring on the balancer can be adjusted if needed or the timing can be offset through the ecu unless it's way off. I find it unlikely the crank/cam gears are a possible problem. Degreeing process will show that. The crank gear appears to be in the wrong slot in the picture.

The damper seems to be ok, I have to doublecheck it.

So I should be fine, when the timing set is set up the way it is, #1 at TDC and I can degree the cam this way properly to cam card specs? And then adjust the ring on the balancer, so it is in line with the crank sensor.

If I rotate the crank gear from where it is now, I can't get to 109 degrees intake center line, and isn't that what matters?
 
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.

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