Pictorial: Installing/Timing a timing belt (6bolt/2g)

blcknspo0ln · 11-08-2007, 08:56 AM

This writeup is specific to a 6 bolt engine in a 2g car.

First and foremost, please read and understand these articles and FAQ's BEFORE you read mine. This is to enforce the understanding of how to do a timing belt, and mine is to guide you to how to do it visually.

(Read down to the "reinstall" portion on Buck's writeup)
Head Removal/Mini Engine Rebuild

luv2rallye's is an awesome, concise article on timing tensioning; also included are the OEM and millertool part numbers for the timing tools:
Timing belt tensioning tips (for 4g63 turbo)

Steve-o's 6 bolt in a 2g writeup:
How to do a 6 bolt swap and what you need

Good ol' VFAQ:

1G: http://www.vfaq.com/mods/timingbelt-1G.html
2G: http://www.vfaq.com/mods/timingbelt-2G.html

1. The difference between a 1g and a 2g tensioner arm. Notice the top (2g) arm assembly has a longer arm. This is not recommended to be used with a 6 bolt front case because it will cause a slight overlap. In a 6 bolt bottom end, used with a 2g, you must use the 2g motor mount bracket, 1g tensioner arm, 1g tensioner pulley, and 1g autotensioner. When putting the tensioner pulley on, make sure that the 2 holes are facing OUT, not in.

***DO NOT REMOVE THE GRENADE PIN FROM THE AUTOTENSIONER***

Overlap seen here:

versus

2. Once you have your tensioner/pulley situated, move on to the actual motor mount itself. The 1G water pump WILL NOT clear the 2g mount. You need to take a die grinder, sawzall, metal cutter wheel, etc to this mount and chop of a piece of it in order to have it bolt onto the engine. One simple cut will do the trick. You can see the cut I made on the top bolt of the water pump.

blcknspo0ln · 11-08-2007, 09:22 AM

3. Now to move onto the cam gears. Let them rest in a natural position first then string the timing belt over only the gears. Take a binder clip (vice grips, zipties, whatever) to hold the belt over the intake cam gear [I like using zipties since the belt does not need to be clamped into place tightly, just enough so that it doesn't slip], it does not matter what position the teeth are in.

Next, take 2 17mm wrenches and position them as such in the above picture. I like to keep my intake cam steady and rotate my exhaust cam clockwise to align the timing marks. You do not need to move the cam gears a whole lot to achieve the correct timing. I've noticed that these cars take only a tooth or two on the exhaust side to move into the correct position. If you find that you are fighting to keep the gears in position, chances are you are rotating them too much.

Here is a picture of the natural position versus the adjust position.

Here is a thread explaining a bit more on why all 4 gear marks do not necessarily line up in a perfectly straight line. Given some calculations (and just by experience) It is not a 180* affair, but more along the lines of 176* or so. The most important thing to understand is that the two center marks need to be parallel to the head surface (and of course each other) and that the 39 teeth are counted. Also, dowel pin position will NOT be at 12 o'clock, it's rather irrelevant, so don't worry about this.

http://www.dsmtuners.com/forums/cyli...#post151581115

***EDIT**
I have included a new picture with GREEN lines. It's a bit easier to count this way. You start counting from 1 at the tooth on TOP of the exhaust timing mark and continue onto tooth #39 which is the tooth that sits directly on the intake cam mark.

blcknspo0ln · 11-08-2007, 02:36 PM

4. Once you have both cam gears in time with the belt, go ahead and string the belt over the idler pulley. That should be pretty obvious.

5. Now comes the oil pump. DO NOT put the belt on just yet. If you did not do the balance shaft elimination, you will need to time your oil pump gear. Easy enough, all you have to do is spin the gear clock wise or counter clockwise until you are able to get the arrow to the 12 o'clock position and when you let it free fall (just spin it to 12 o'clock and let it go) it will either fall clock wise or counter clockwise. When the arrow dips to the ccw position (towards 9 o'clock) then it is in time. If it is not, keep spinning it until it does fall correctly. If you do not have balance shafts then there is no need to time the gear, but I always do just for the sake of doing so. Once it is that way, play with the belt teeth and gear until you get it taught (no slack) and timed correctly.

6. Go ahead and take a 1/2" ratchet to the crank pulley bolt and spin the crank until it lines up the arrow to the arrow on the front case. There's no exact science to this, spin it and play with the belt, again, until it is taught and not skipping any teeth on the belt.

blcknspo0ln · 11-08-2007, 02:40 PM

7. Alrighty, now we go to the timing tensioner pulley. This is the most critical part so listen up. Keep the timing tensioner bolt loose, but finger tight. This way you limit the amount of torque you need to put down on the bolt, while still being free. Go ahead and string the belt over the pulley. It should look like this:

Now take your pulley tool (Available through OEM or millertools.com) and put it on a 1/4">3/8" adaptor to your wrench.

Now, you can choose to tension the pulley either clockwise or ccw. How do you determine which way you need to go? It's the type of tensioner arm you are using. In my example (and most 6 bolts should be set up this way) It is a 1g pulley, 1g autotensioner, 1g tensioner arm, 2g motor mount assembly, 2g idler pulley (same as 1g).

Clockwise - 1G tensioner arm
Counter Clockwise - 2G tensioner arm

Here is a picture of the pulley going clockwise. Again, because I am using a 1g tensioner arm.

Keep putting tension on the pulley until you can feel the grenade pin on the auto tensioner begin to loosen up (because you are now pushing down on the autotensioner arm). This is generally accepted as the "safe" tension for the belt. DO NOT use this as a sole judgement as to how tight your belt should be. You need to measure the tensioner gap between the rod and the auto tensioner body.

*EDIT* More tips:

1G tensioner arm - Since you are rotating it clockwise and you tighten the bolt clockwise, when you torque the bolt down it will cause MORE tension on the belt. So, to prepare yourself for this, start by tensioning the pulley until it is at the threshold of the pin being loose. This will be on the loose end of the tolerance and when you torque the bolt down, it will bring it more towards the middle/end of the tolerance, but still acceptable.

2G tensioner arm - Since you are rotating it CCW and you tighen the bolt clockwise, it will loose the tension when you torque the bolt down. To counter this, you will need to take the tbelt tension to the tight end of the tolerance and torque down so that it brings it to the middle/looser end of tolerance.

This is a guesstimate, but I just timed a car yesterday and gapped correctly and *eyeballing it* it looked like a 1/4" belt deflection on the slack side of the belt (between the pulley and bottom of exhaust gear) on each side.

**IMPORTANT**
Last thing to note is that when you are tensioning the pulley, HOLD your desired position for 10-15 seconds before you torque the bolt down. After you hold, check the pin for looseness and then proceed to torque down if everything is good. You are holding the position so that you give the autotensioner a chance to adjust to it's truer position (which is a hell of a lot more accurate than tensioning and torquing quickly). Of course, still check gap after 15 min.

Once you get the grenade pin to spin freely, go ahead and take a wrench or socket wrench and tighten the bolt down to 35 ft/lb. At this point you want to verify that all timing marks are still on point. One thing to check is if the cam timing marks are still straight. If they are not, you may want to rotate the exhaust cam one tooth to offset the "natural" movement.

[note]
Also a comment on the natural movement. I've found that this natural movement occurs when you do not accurately keep the belt tight between the oil pump gear and crank sprocket. What happens is if you are on the looser side, the tensioning of the belt will cause the crank to spin about 1/2 tooth, hence causing that funky exhaust cam gear to move. So just make sure you are not letting slack between those two gears.

Taken from BUCK'S writeup :
"Next.... you were told to do six revolutions because the oil pump sprocket lines up with its timing mark every 3 crank revolutions. 3 revs for the oil pump x 2 revs for the cams = 6 crank revolutions for ALL of the timing marks to line up again. That means every 6 revolutions everything will line up.. you can't just stop at 7 or 8 revolutions and expect it to all line up. You have to line up the marks, go EXACTLY 6 REVOLUTIONS, and check to make sure all the marks are still aligned. Hope that makes sense, I'm trying to make this as brief as possible. "

So, spin the engine 6 times (watch the dowel pin, it should start at 12o'clock and do 6 FULL revolutions to 12 o'clock again before all timing marks line up again.) WAIT 15 minutes and then check the gap on the auto tensioner with 2 drill bits. The factory spec for the gap is between .15 and .177"; Commonly used drill bits to measure these sizes are 5/32" (.157) to 11/64 (.172). To be obvious, the gap must LARGER than 5/32" and smaller than 11/64".