Where does your timing belt ride?

[xxNocturnalxx]

Dang, my first impression is that is not normal, my car is at the shop otherwise I'd look right now. Check how centered the cam lobe is riding on the rocker. I would get a set of stock cams to throw in there and see what happens, your cams might actually be out of spec which would be crazy especially in that direction.

edit: The cam lobes to caps progressive gaps look to be normal.

 

[WES_393]

I pulled out my old nasty spare head and took some pics/measurements. This head is a bone stock 2g head that was pulled from a running engine. My cam lobe to cap clearance is much wider than yours. Not sure if it's a 1g/2g thing, but I could fit at least .060 worth of feeler gauges between every lobe and the caps, with the exception of E2. Take a look.

E5, the cap where your farthest left lobe is nearly touching.

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E2, my farthest right cam lobe is the closest one with about .030 clearance.

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Based on this, I'd say it's possible your cam lobes are out of spec somehow. My poorly machined stock 2g cams have more clearance than your aftermarket cams. Definitely worthy of noting.

 

[NHerron]

OP, I have talked to the guys that make our cams and they are pretty helpful. Maybe they can give you specs for the thrust portion on the cam. Are they new cams by the way?

 

[rlacasse1]

I've had my timing belt ride that way on every DSM I have owned. Never had an issue with it at all.

And the timing belt had ridden that way on the gears since long before I got the cars. You could see where the belt typically rides.

 

[xxNocturnalxx]

Interesting, my belts have always been fairly centered.

 

[Prib9671]

OP, I have talked to the guys that make our cams and they are pretty helpful. Maybe they can give you specs for the thrust portion on the cam. Are they new cams by the way?

They are used but barely, I bought the complete head with cams from him a friend who says when installed on his car it might have been slightly off center but not like this.


The cam lobes do not ride centered on the rocker rollers on the lobes starting from the tranny side. It does become more centered by the 2 by the timing side just like the lobe to cap distance.

 

[narf]

I've built 5 different motors, each 1 has had the belt sit to the left. Why, can't tell ya... All have ran good.... Belt wise anyway...

 

[Prib9671]

I've built 5 different motors, each 1 has had the belt sit to the left. Why, can't tell ya... All have ran good.... Belt wise anyway...

Can you tell me for sure if they overhung say like .01"-.02" like mine does. I work at a machine shop and I'm thinking I might just cut like .05" off both cams and call it a day.

 

[phunny]

Can you tell me for sure if they overhung say like .01"-.02" like mine does. I work at a machine shop and I'm thinking I might just cut like .05" off both cams and call it a day.

That's exactly what I'd have done.

 

[Prib9671]

That's exactly what I'd have done.

Thanks for the response. That's good to know someone else has done this. As long as I get them sitting flat in the machine it will be easy. There should be no ill effects concerning perpendicularity and therefore they won't "wobble" once reinstalled. Did you use a mill or what?

 

[narf]

Thanks for the response. That's good to know someone else has done this. As long as I get them sitting flat in the machine it will be easy. There should be no ill effects concerning perpendicularity and therefore they won't "wobble" once reinstalled. Did you use a mill or what?

bolt the head right to the table as long as the deck is semi flat then end mill them. You may also be able to turn the cam alone in a lathe as long as you can grab it right/true. Ive never had the belt hang off.... but right to the edge.... maybe .01 over ??? I just ran them like that.

 

[Prib9671]

I'm just going to run it like that. If it does anything weird once its running I will just tear them out and cut them down then. Thanks for all the help guys. I will report back hopefully soon, good or bad.

 

[Prib9671]

RESOLVED: Got the car running and the belt location is fine now. I guess it hadn't rotated enough to seat itself after I initially set the tension and rotated it by hand. Glad it wasn't faulty cams!

 

[91mits]

RESOLVED: Got the car running and the belt location is fine now. I guess it hadn't rotated enough to seat itself after I initially set the tension and rotated it by hand. Glad it wasn't faulty cams!

mine sits similar to that and havent had a problem for 5000 miles or so, i noticed jeffrey bush from english racing, his belt sits similar to mine too and thats a 1000+awhp motor, i wouldnt really worry ..i was at first but every cars different..

 

[DSM1G90]

Tensioner pulley inner surface may not be square to the block. It could be leaning forward just a tad where the belt wants to ride on the higher edge of the pulley causing the belt to ride inward on the sprockets.

Where is the belt riding on the pulleys - center or on the edge?

 

[xxNocturnalxx]

RESOLVED: Got the car running and the belt location is fine now. I guess it hadn't rotated enough to seat itself after I initially set the tension and rotated it by hand. Glad it wasn't faulty cams!

Ahhh jezus!

Glad you got it

 

[NHerron]

Glad to hear you got it worked out

 

[Archer Fabrications]

mine sits to the left a little bit also, i also sort of have a wobbily intake gear a little bit... barely but noticable when its running. im gonna take a pic in upload in a little bit.

edit: looks like the intake cam is like a hair farther out then the exhaust, both sit with some cam room to the belt on either side.

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ive tried toghtening the cam gear bolt and it's as tight as it gets