T-belt Q:

[gvr4ever]

When putting the t-belt back on, the cams don't stay aligned after the tension is put on. The exhaust cam seems one tooth late. I tried it again, and try to advance it just a tad, but it's still off when the tension is put on and the engine is spun.

Any stoopid tricks? Common half hour t-belt guys. How do you get it perfect first try? BTW, I'm not eye balling it. I'm using a flat tool to line them up and check.

 

[jepherz]

are you using clamps or something on the cam gears to hold the belt in place once it's over them? the cams won't want to sit correctly lined up with each other at TDC because of the cam lobes, so you have to compensate a tooth sometimes when you clamp the belt on. No balance shafts helps speed it up too.

 

[gvr4ever]

Ya, I'm using clamps. I'm finishing a BS job. /ubbthreads/images/graemlins/smile.gif I was hoping to hear it go vroom tonight. Even with office clamps on the belt, the cam timing marks look perfect. When I remove the auto tensioner tool, spin the engine, it ends up being off just a tad. I'm trying to compensate for what it does, but I'm still not able to make it perfect.

 

[Diego]

agree with jepherz +1

use a zip-tie on the cams to hold the belt up there is option 1 and your alone by yourself which is frustrating /ubbthreads/images/graemlins/banghead.gif

2. have a buddy hold 2 wrenches on the cams to stay in postion up top while you do your dirty looping downstairs.

3. if bs is out then this is a heck of alot easier.

make sure your lines match up and presto

Ps. if your cams lock a bit and you want an extra bit of room clearance on cams for tension/slack bump the crank ever so slightly and it should give you enough room to play with up top...


Diego

 

[Barnes]

IMO, if the marks line up when you clamp it, and they are off only a little bit after, you are fine. I've never been able to get all four grooves to line up perfect in the end. Not sure why that is.

 

[chucklesas]

Once you line up the top gears and get the belt on them, you need to run down the right side, under the idler pulley and over the oil sprocket and finally the crank sprocket. You need to make sure that any slack in your belt is on the left side of the crank sprocket and cam gears. Then that slack will be taken up when you turn in the tensioner pulley. That should keep everything aligned.

 

[gvr4ever]

Ya, it should. I don't know whats going on. I got closer advancing the exhaust cam one tooth. Still not perfect, but better. The intake cam is perfect. No problems. The exhaust seems to change, even with a clamp left on, and the slack on the side of the auto tensioner pulley. I followed the v-faq. I'm putting it on in the right order.

 

[talon]

I've ran into this problem before on a friends car.

For instance once everything was timed, and you set the tensioner and spun the motor a complete cycle (12 revolutions I think), the intake cam was off by one tooth up. So what I did was time the car with the intake cam one tooth off down, then set the tensioner and spin the motor a complete cycle, and everything lined up perfectly.

 

[gvr4ever]

Okay, I got it. I had some problems with the tension, but it looks good now. After some google detective work, I found a method of using a 4mm alen wrench to check the gap. I can fit it in, but not spin it. It looks good.

I'm going to start putting stuff back, if anyone disagrees with this, let me know.

 

[dsmless]

I ran into this problem too but after checking and double checking decided to spinn the engine by hand with out the plugd in and spunn it like 20 something times, it never hit or jamed up on nothing so I fired it up and have been driving it coast to coast 3 times already so just use your best judgement

 

[Bonezilla]

click

 

I have a few free minutes so I will share my method which is quick and easy.

1. Paint the gears. Count clockwise from the timing mark on the exhaust cam tooth 5 teeth and paint this tooth. Do the same on the intake cam but count 17 teeth. Do the same on the crank, counting 11 teeth from the dowel pin for the harmonic balancer.

2. Paint the belt. Pick any SPACE and paint it. Count 27 spaces, paint that. Count 69 more, paint that.

Note: All counting is clockwise.

3. Line up all the paint lines. The cams/crank don't really need to be right on TDC, just close. Key is to line up the marks.

4. Tension the manual tensioner. I do this by feel.

5. Rotate the motor 1 full revolution and make sure you are satisfied with the timing. Pull the grenade pin.

6. Rotate one more full revolution. Then try to put the grenade pin back in. If you can, the tension is correct.

7. Beer.

 

[gvr4ever]

I guess I should say, that I got this done awhile ago. /ubbthreads/images/graemlins/smile.gif Car is back on the road. For me, putting the exhaust cam one notch forward seemed to have done the trick. It's still not perfect, but better. I've seen a few pictures of cams that look 100% perfect. I don't think mine can be. It ended up being half a tooth off instead of a full tooth off.

Thanks for all the help.

 

That is fairly common. If your head or block have ever been surfaced, then the dimension from the crank to the cams will change slightly, putting your timing off a small amount. This is the reason you would want to use a thicker HG when you do machine work like this, but many don't.

 

[gvr4ever]

It's a stock engine at 120K miles. BS no longer balancing, but long block has never been touched.

 

I wonder, was it like that when you took off the old belt? I know some do line up better than others, stackup of tolerances I guess. Still a full half tooth strikes me as a lot.

I don't really pay that much attention anymore since I do mine by the numbers (which I took from an engine that was one of those 100% perfect ones). If your idle vacuum is normal and it runs fine I wouldn't really worry about it.