Timing chain question

[wh1-t]

Hi guys, I am in need of some advice for reinstalling my timing chain. Long story short, the bolts holding the cam gear fell out. The previous owner had this engine built (about 5k miles ago), and the bolts they used were only into the cam about 2 threads deep. This is a double roller chain (part# on cam gear = SRS-3129 DG). I intend to reinstall the existing parts (with new bolts of course).
I can see the imprint of how the gear was positioned on the cam, so I can reinstall it that way. My question is: do I line up the dots to face each other (crank dot at 12 o'clock, and cam dot at 6 o'clock), or would they both be at 12 o'clock?
The crank gear is installed with the dot closest to the key. I see that it has the "A" and "R" marks next to the other keyways. When my crank dot is at 12 o'clock, the key is at about 1 o'clock. I assume that this means the dot represents TDC?
Thanks in advance, I've had this car for about 7 years now, and still learning!

 

[wh1-t]

I just noticed that this is being registered as my first post, I guess it's been a couple years since I've been here, maybe my other posts disappeared? Oh well, I will reintroduce myself. My name is Todd B., and I am a plumber in Omaha, NE. I've been into the Buicks for about 7 years now, and this site has always been a huge help to me. Unfortunately, I never seem to have time for the old car, I'm just trying to get it ready for the spring (if that ever comes). We just had snow here a few days ago . Thanks guys!

 

[GNONYX]

I think the only way I can help you if you read Casper's Cam Sensor installation to make sure the 25* degree after TDC and #1 piston is in the top location.
This picture shows shows cam is 6 o'clock and crank is at 12 o'clock. The other picture is a reminder of not forgetting the Oil Slinger.

 

[wh1-t]

Thanks Onyx, so from the pictures, I see that the dots are aligned with each other. Can I assume that this is how my set needs to go together? After that, I just need to follow the cam sensor installation instructions (so that the injectors are in time)? I was thinking about ordering the cam sensor test cap (with the LED's), when I get to that part.
I apologize for sounding ignorant, this is all new to me. I just wish the guy had installed the correct length bolts to begin with, and saved me the headache!

 

[GNONYX]

Thanks Onyx, so from the pictures, I see that the dots are aligned with each other. Can I assume that this is how my set needs to go together? After that, I just need to follow the cam sensor installation instructions (so that the injectors are in time)? I was thinking about ordering the cam sensor test cap (with the LED's), when I get to that part.
I apologize for sounding ignorant, this is all new to me. I just wish the guy had installed the correct length bolts to begin with, and saved me the headache!

I would do the cam Sensor first since this will position the #1 piston in top location, cam and crank sprocket in line with each other.
These other pictures shows what I did as far as marking the new 25* after TDC; very important I used the original TDC mark on "0" to align both cam and crank sprockets, and move to the new 25* after TDC for the cam sensor setting.
If you can see very closely at the first picture the two timing marks, the original one is on the "0" TDC during the setting of both cam and crank sprockets are line up. After all is put together, move the crank to the new 25* after TDC to set the Cam sensor, and don't forget to prime the oil before starting the engine.

 

[GNONYX]

Her is Casper's site and real cheap Cam Tool
http://www.casperselectronics.com/store2/product_info.php?cPath=22&products_id=653

 

[wh1-t]

I think I am getting confused now (sorry), and maybe it's because I should have explained my situation better. I am working backwards, as I already have the timing cover off. The car would not start one day, and I suspected the timing chain, because it was turning over fast, and not building oil pressure on crank. I pulled the cam sensor, and had a friend crank the motor while I watched the chain through the hole. The chain was spinning, but the cam was not. I pulled the cover to find the two bolts had fallen out, allowing the chain to spin without the cam. Now, I guess, I am trying to get the gears back to where they should be. Then I can get the cover on, and deal with the cam sensor when it is time. I probably should have disclosed this in the first place, I was trying to keep it short. Thanks again for any feedback!

 

[Cbring]

Good write up for installing cam sensor:



http://www.vortexbuicks-etc.com/cam_sensor.htm

 

[GNONYX]

It doesn't matter which way you are you doing it, you still need find the #1 piston on top and also see if the crank sprocket is at 12 o'clock so everything is line up for timing chain installation, and Cam Sensor installation. If all is not align then you will have a hard time trying to start the engine, possible taking everything down again to the first place of aligning the dots and the #1 piston position.
Reminder again, DON'T FORGET TO PRIME THE OIL AND BUILT UP OIL PRESSURE BEFORE STARTING.

 

[wh1-t]

OK, I will pull the valve cover, and get both valves closed on number 1. Then rotate crank until TDC, and see how the dots align. One question on priming the oil pump: I saw a post where a guy suggested pouring oil into the cooler line, then rotating the pump CCW, then CW to prime. Is this effective, or is packing the pump necessary? Thanks again!

 

[RmvBfrFlght]

No need to pull the valve cover. Install the crank gear with the dot at 12 o'clock. And the cam gear at 6 o'clock. Make sure that they are lined up to each other. Torque the cam gear bolts.

Now turn the crank 360*. This will put both the crank and the cam gear dots at 12 o'clock. The engine is now set to TDC #1.

Install the oil slinger, timing cover, damper and so on. Rotate the crank so it is 25* ATDC and drop and align/set the cam sensor.

RemoveBeforeFlight

 

[earlbrown]

while you have the timing cover off it would be a good time to open up the oil pump and inspect it for any potential problems.

and if you're handy with a Dremal tool, do some flow mods and free up a few horsepower.

 

[wh1-t]

Thanks for the info RBF, and thanks for checking in on this one Earl! This cover has the seal that installs from the front, so can I assume that it is an aftermarket cover? If so, do you still recommend modding it? Also, do you have any feedback on the pump priming procedure (that I mentioned), or is it just better to pack the thing? Earl, it's good to see that you're still at it. Yours and SW's info was always helpful to me on the old TB"S" site. Thanks guys!

 

[GNONYX]

No need to pull the valve cover. Install the crank gear with the dot at 12 o'clock. And the cam gear at 6 o'clock. Make sure that they are lined up to each other. Torque the cam gear bolts.

Now turn the crank 360*. This will put both the crank and the cam gear dots at 12 o'clock. The engine is now set to TDC #1.

Install the oil slinger, timing cover, damper and so on. Rotate the crank so it is 25* ATDC and drop and align/set the cam sensor.

RemoveBeforeFlight

Hi RBF, Once he has TDC and both dots lining up, won't the engine be out of phase if his turns the crank 360*? The reason why I'm asking this since I replaced my timing chain, The #1 piston was on top, both dots were line up. Line up both sprockets dots, replaced timing chain and after I primed the oil I moved the crank sprocket to the new setting of 25* after TDC and then installed the cam Sensor according to Casper's instruction. Car started up with no issue; unless I'm missing something

 

[GNONYX]

OK, I will pull the valve cover, and get both valves closed on number 1. Then rotate crank until TDC, and see how the dots align. One question on priming the oil pump: I saw a post where a guy suggested pouring oil into the cooler line, then rotating the pump CCW, then CW to prime. Is this effective, or is packing the pump necessary? Thanks again!

I didn't pack the oil pump with Vaseline as most do
I first filled the oil filter as much as I can and then put 3 quarts oil , then I remove the lower oil cooler from the radiator taped it against some pipe so the oil cooler is vertical position. Then place a small funnel inside the oil cooler hose, you will need a Chevy oil pump prime tool and place it inside the Cam Sensor hole; make sure the tool slot is fitted on the oil pump shaft. DO NOT start the engine, if your oil pressure gauge is electric then just turn the key to the "ON POSITION" , and have someone inside the car telling you that you have oil pressure. Attach the cordless drill machine to prime tool and run it at CCW position, at the time fill the oil cooler hose with about 1-1/2-2 quarts of motor oil, or until you have oil pressure present. Once you have oil pressure, re-install the oil cooler hose back, set the cordless drill machine to CW until the other person inside the car tells you that you oil pressure on the gauge. Remove prime tool rotate crank shaft to new marking of 25* after TDC install the Cam Sensor as per Casper's Instruction.

 

[RmvBfrFlght]

Hi RBF, Once he has TDC and both dots lining up, won't the engine be out of phase if his turns the crank 360*? The reason why I'm asking this since I replaced my timing chain, The #1 piston was on top, both dots were line up. Line up both sprockets dots, replaced timing chain and after I primed the oil I moved the crank sprocket to the new setting of 25* after TDC and then installed the cam Sensor according to Casper's instruction. Car started up with no issue; unless I'm missing something

Before the cam chain is installed the short block #1 cylinder piston is at the top every 360* of crank revolution. But neither is considered TDC as the cam timing isn't in place. The compression/firing (TDC) has not yet been established.

So can use either revolution of putting #1 piston at the top to align the cam timing chain set up. That is what defines the TDC #1 firing stroke (the cam).

When setting up the cam chain gears, using 6 o'clock on the cam gear and 12 o'clock on the crank gear makes it easy to be sure that they are truly lined up. But, that is #4 TDC (firing). Once the timing set is installed, turn the crank 360* (one full rev), and with the cam rotating half that it is now at 12 o'clock.

And the engine is now at #1 TDC (firing stroke, both dots at 12 o'clock).

Note that if the engine is left at #4 TDC and the cam sensor installed (crank moved to 25* ATDC #4), the engine will still start and run. Just that the injector firing will be 360* out on the crankshaft to intake-valve timing.

RemoveBeforeFlight

 

[wh1-t]

Thanks guys for the info; is the reason that there are conflicting answers, that the cam sprocket (and dot), could be installed in either position (as per the bolt pattern)? I.E. the sprocket could be installed 180 out, showing the dot at 6. The difference in my case, I guess, would be that I can see the imprint of the sprocket to determine the position. Believe me, I'm not trying to complicate things, I just want to make sure I am understanding everyone correctly!

 

[earlbrown]

You can do either because the cam gear spins at half the speed of the crank gear. If you line them up 'dot to dot', then turn the crank one revolution, both dots will be at 12:00. One more turn and you're back to 'dot to dot'.

 

[wh1-t]

I think I understand the logic now (finally). I was overlooking the 2:1 ratio with the gears, and confusing myself. On another note; the gasket kit I ordered came with the wrong oil pan front gasket (which I have read is normal). I did not intend on dropping the pan, and was wondering about the best alternative (no gasket with Right Stuff, for example). Any recommendations on that? Thanks everyone!

 

[GNONYX]

Everyone has their own version of the oil pan gasket. I myself installed a rubber/fiberglass oil pan gasket and no leak.​

As far not dropping the pan, that's one thing you might not have a choice. The oil pan cover has to drop down in order for the timing cover to slide onto both dowel pins and then you can bolt the oil pan with gasket up against the timing cover.​

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