Putting my t-belt on my new stroker, and something about where I'm ending up on the tensioning just doesn't seem right. The pulley holes always ended up slightly left of straight up on the original 2.0, but with both my 4k mile used OEM belt, and a new Gates belt, the holes are straight up or maybe even slightly past that now.

The motor rotates fine, passes the .150" after 15 minutes test, and the crank/cam gear alignment is dead on...but it seems that in this position the pulley is VERY close to rubbing on the bracket, if it isn't already. I can't hear or feel any interference, but it is close enough that I can't get a .03" tie wrap between the pulley and bracket. Unfortunately I can't really get my feeler guages in there to check more accurately without pulling it apart and measuring the pulley-to-bracket clearance on the bench.

Does anyone know how far CW the eccentric pulley can actually rotate before interferring with the bracket?

BTW - all components are OEM and are either new, or have < 5k miles on them and check out in like-new condition.

Pics below showing alignment, .150 drill bit sitting perfectly (it's perfect on either side of the tensioner rod), etc. This is after 2 sets of 6 rotations and 15 minutes of tensioner stabilization.

Any opinions welcome.

Craig, I just installed a Gates Racing t-belt on my 6 bolt and the holes in the tensioner pulley are almost exactly in the same location as yours. As long as the tensioner rod is within specs (and it clearly is) I doubt that you will have any issues.

Actually, my pulley is rotated a bit more clockwise than yours and I'm getting a bit of a whining sound from the t-belt so I will be loosening it up a hair. The rod length ended up at a bit under minimum spec but I thought I would be ok. Live and learn. Point being that my tensioner pulley is rotated more than yours and I don't have any issues with the pulley interfering with anything.

Hey Romeen...LTNS

I'm mainly concerned about potential clearance issues between the bracket and pulley. I was thinking about loosening the eccentric pulley a bit also, and letting the tensioner take up more of the slack. The upper limit on the tensioner rod is .18" for a new belt...and with a free (working?) length of .47" on the tensioner rod and a belt that is less prone to stretching, I think it would be ok to lean toward the upper end of that window.

I may just let it ride for now and see what happens once I start it up...but it is definitely something I'll be mulling over until I actually drop the engine back in.

On a related note, I got the degree wheel mounted and TDC calibrated, and everything is definitely off a bit. I won't have any numbers until I get the cams degree'd this weekend, but they look to be off a degree or two at true TDC.

I'm mainly concerned about potential clearance issues between the bracket and pulley. I was thinking about loosening the eccentric pulley a bit also, and letting the tensioner take up more of the slack. The upper limit on the tensioner rod is .18" for a new belt...and with free (working?) length of .47" on the tensioner rod and a belt that is less prone to stretching, I think it would be ok to lean toward the upper end of that window.

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You've got a good point. I was hoping that my belt would stretch a bit and the whine would subside but I doubt these kevlar belts are going to stretch much if at all.

I may just let it ride for now and see what happens once I start it up...but it is definitely something I'll be mulling over until I actually drop the engine back in.

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Well you don't want to be losing any sleep over it. Us old guys really need it. I wish we could get Bruce back on the forums.

On a related note, I got the degree wheel mounted and TDC calibrated, and everything is definitely off a bit. I won't have any numbers until I get the cams degree'd this weekend, but they look to be off a degree or two at true TDC.

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So is it just a matter of adjusting the cam gears? I've never worked with the adjustable gears before.

It's interesting how such small adjustments can affect the motor's operation. When I did my t-belt I noticed that the dowel pins on the ends of both cams were bent towards the exhaust side of the engine (CCW). Especially on the exhaust cam--it was almost ready to break off! Fortunately a local shop was able to remove them and I found some 6mm steel dowel pins locally which I pressed in. Anyway, they were bent bad enough that it was causing the cams to be rotated just a bit CCW from where they should have been. Now that the issue is fixed my car clearly runs noticeably smoother and it got rid of a momentary hesitation I had when getting going from a stop.

Engine looks clean.

Craig, I've had my tensioner pulley way past that point. I think at one point I had the holes close to 2 o'clock. And I have never had any issues with rubbing that I noticed.

And with the many times I've set/reset the timing on my car, I have never been able to get the tensioner to arm gap correctly. My gap is always under the specs, even with all brand new parts.

I think you'll be fine with it.


Romeen, check out this link for more degreeing info.
http://www.dsmtuners.com/forums/cylinder-head-short-block/314111-cam-degree-degreeing-degreeing.html

Brian...

Isn't your 2g supposed to be in a different orientation though? Or is it a 1g/6 bolt motor?

romeen said:

When I did my t-belt I noticed that the dowel pins on the ends of both cams were bent towards the exhaust side of the engine (CCW). Especially on the exhaust cam--it was almost ready to break off! Fortunately a local shop was able to remove them and I found some 6mm steel dowel pins locally which I pressed in. Anyway, they were bent bad enough that it was causing the cams to be rotated just a bit CCW from where they should have been.

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That's bizarre. I would think that with as close a fit as those pins have, they would shear off instead of bend. And if they were bent, how were the gears still flush against the cams?

Those babies must have experienced a really bad day at some point in their past!

It's a 1g 7 bolt motor. I believe I follow the 1g timing guide and rotate my pulley clockwise.

That's bizarre. I would think that with as close a fit as those pins have, they would shear off instead of bend. And if they were bent, how were the gears still flush against the cams?

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They weren't. I noticed my cam gears were wobbling. I thought my cam pulleys had warped but when I removed them they were true/straight as can be. Then I noticed the dowel pins.

Bummer... did your cam bolts just back out or what?

Good thing you caught it when you did!

calan said:

Bummer... did your cam bolts just back out or what?

Good thing you caught it when you did!

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No, the cam gear bolts were on nice and tight.

Actually, I think it's breaking those bolts loose that causes the problem. No doubt you've experienced how hard it can be to break those suckers loose. Think of all that force you are applying through your breaker bar and how much opposing force your helper is using on the camshaft to keep it from spinning. And the only thing connecting it all together is a single 6mm dowel pin.

I think the bent dowel pins may be more common than some guys might expect although not necessarily as severe as mine.

romeen said:

No doubt you've experienced how hard it can be to break those suckers loose.

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You wouldn't believe. I tried a 1/2" wrench with cheater pipe, breaker bar, breaker bar with cheater pipe, DeWalt 1/2" cordless impact (300 ft.lbs.), Snap-On 1/2" cordless impact (460 ft.lbs.), and finally an Ingersoll Rand 1/2" air impact (1100 ft.lbs.). The IR gun was the only thing that helped. I have never run into an issue that I needed such a hefty gun other than the cam gear bolts.

Damn... what are you guys torquing those things to?

j/king... I know they can be tough, but with the right wrench to hold the cams firmly and a bit of heat, I can usually break mine loose without "too" much effort. (I torque them to around 70lbs with blue Loctite when re-installing them).

The first time I pulled them though...they were a biatch to break loose

snowborder714 said:

I have never run into an issue that I needed such a hefty gun other than the cam gear bolts.

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I don't know...trying to break O2 housing > hotside bolts loose (when no anti-sieze was used) while the turbo is on the bench is my nemesis. There is just no way to hold or clamp the thing to get any leverage on it. They are either stuck for life, or have come loose and are completely missing.

The plugs in the OFH were a close second, until I realized that if you heat them to about the temperature of the sun's core, they'll come right out...

Sheesh - I've never had cam bolts on THAT tight that I needed an impact wrench. Mine usually come off no problem with just a breaker bar and a wrench holding the cam w/ a board to distribute the load against the head from the wrench. The only bolt that has given me grief on all my DSM's is the nose bolt. I've had some that were just absolutely ridiculous to get off, to the point of me needing to break out my Nitrocat impact wrench.
Did you get your timing belt all straightened out?

lacroixdp said:

Did you get your timing belt all straightened out?

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If that means leaving it exactly like it is pictured in the first post....yep!

I've always followed the mantra: if the grenade pin fits, you must acquit. Haha Does the grenade pin slide in and out easily?

Did the block get decked, and did the head get resurfaced?
This will bring the cams down closer to the crank and require a little more tensioner adjustment to achieve the desired .150" - .180" timing belt tension.
This could be why you're tensioner pulley is a little further than usual.

I use a 5/32 drill bit which is .156" when I do a timing belt.

Got the cams degreed and adjusted, and everything including the belt tension looks good.

Results here.

Romeen, I know you and I have recently talked about our bent dowel pins via PMs. Where did you say you got yours again?

DSMunknown said:

Romeen, I know you and I have recently talked about our bent dowel pins via PMs. Where did you say you got yours again?

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I got them from a local hardware store. They are not nationwide. 6mm is the size you need. I forget the length although a bit too long shouldn't be a problem. I can grab you a pair and send them to you if you want.

The hardest part for me was getting the old ones out. They had become distorted and wedge in there really tight. A local shop ended up welding a bolt to the tip of the dowel pins and then hammering them out.

BTW, this was at a local business that works only with camshafts (mostly industrial). You should see the cams for a Caterpillar! Probably 7-8 feet long and bigger around than my thigh.

Sorry to go off topic Craig, just thought that was interesting.

Np