Cam wheel torque

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tima01864
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Cam wheel torque

Post by tima01864 »

I had to replace a cam sprocket, Getting it off was easy enough. A few whacks on the wrench broke it free.
Reinstallig is a problem, I checked the torque value 87lbs, That is what my wheel lugs are torqued to, massive.
I read thru some posts and tried those techniques, Wood under a lobe etc., I was able to restrain the wheel enough to get 40lbs on the bolt.
My next course is A loaner impact wrench, if one is available. But getting it torqued with an impact wench? My best bet is to mark the bolts position and give it a few blips? Topic
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Re: Cam wheel torque

Post by 18Fiatsandcounting »

In recent times I've done this with the cams off the engine, but the last time I torqued the cam bolts while on the engine, I used an old timing belt wrapped around the cam wheel, clinched it tight with vise grips, and held it in place while torquing. Perhaps it took two people; I honest don't remember.

Impact wrench method: My impact wrench has a knob marked 0 through 5. When set to zero, the impact wrench puffs but little else, so presumably that's effectively zero torque. 5 seems to be full force for a given air pressure. So, if you can borrow / purchase an impact wrench that has this, try setting it to 3 or the like and test it by tightening a wheel lug. Then check the wheel lug with a torque wrench to see how close you got. Repeat with different air pressures and wrench settings until the impact wrench seems to be torquing to 80 to 90 ft lbs. That's probably all the closer you'll get, but it's probably close enough.

-Bryan
tima01864
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Re: Cam wheel torque

Post by tima01864 »

Autozone let me use a cordless, rated at 300lbs torque. I used your method on the lug nuts. All the cordless would give me is 40lbs, Any other impact wrench they have will not fit in the space in front of the wheel. So for now I will have to live with it until I get something that will actually torque.
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Re: Cam wheel torque

Post by 18Fiatsandcounting »

tima01864 wrote:Autozone let me use a cordless, rated at 300lbs torque.
Maybe it was 300 inch pounds and not foot lbs... I'm just saying. 8)

But in all seriousness, now that I think about it, this was a two person operation for me in the past. One person to pull on the torque wrench, and the other person to hold the cam wheel tight with an old timing belt.

What would be really cool is if somebody made a tool that fit between the two cam wheels and locked them with respect to each other. I'm thinking kind of a stepped wedge that would fit in the wheels' grooves. Turning the lock bolt would force the wedge harder against the other wheel, and thus lock the wheel as you torqued the nut.

-Bryan
tima01864
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Re: Cam wheel torque

Post by tima01864 »

Hmm., FIAT has a tool if you can find one. Cogged and bolts to the cam box to prevent turning, Saw it in the manual. Someone suggested a belt wrench using the old belt to hold it steady. I agree this is a two person job lacking the impact wrench. Was hoping to get this done today, Put it back together will try another day when I have help, Already have two days into this.

I thinkit was advertised at 300ft lbs, maybe on smaller bolts or maybe just to reverse not install.

https://www.autozone.com/power-tools/im ... /52380_0_0
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Re: Cam wheel torque

Post by tima01864 »

Looking for suggestions for a good available impact wrench, Prefer cordless
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Re: Cam wheel torque

Post by Spider951 »

It is possible to make a version of Fiat Tool A.60446 (cam pulley gear lock). I did (pictured below: top, side,and underneath views with cam gear removed; works for both intake and exhaust sides). It took a few hours to build. You need some angle iron and flat steel bar; power drill; some way to bend steel bar (I used a bench vise and small sledge hammer, helps to apply heat); angle grinder or other means to cut "teeth" in steel bar (files will work, especially in combo with angle grinder); welder to attach angle iron and steel bar. [I described this back in May 01, '18 under topic dealing with the infamous crank pulley nut.]. Basically all you are doing with the Fiat tool (or my redneck version) is providing some serious blockage for movement of the cam pulley. I couldn't make the timing belt hack to work for me (I think my old belt was too old and rotten as I recall) to get to the prescribed 87 ft-lbs. [As I recall I ruled out the air impact wrench method (for reasons I don't remember - trust?, lack of means to gauge torque?)]

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tima01864
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Re: Cam wheel torque

Post by tima01864 »

That will work,. The torque on that bolt is massive. Wish I could borrow it.
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Re: Cam wheel torque

Post by aj81spider »

Just a note of caution on checking the torque of an impact wrench on lug nuts. I believe the torque specs for the lug nuts is 65 ft-lbs. When I bought my car one of the issues it had was a stripped lug nut hole. The previous owner said a tire shop had reinstalled the wheels using an air impact wrench and stripped one of the holes. I had to replace the hub.

I don't know if Fiat hubs are prone to stripping or if the shop was particularly egregious in their enthusiasm for securing the tire, but since then I've been pretty careful about torquing wheels.

It would be bad if while experimenting with an impact wrench you stripped a lug nut hole.

On a separate note - this is what I used to change my cam wheels. Worked great and was a one person job.

https://www.amazon.com/gp/product/B000T ... UTF8&psc=1
A.J.

1974 Fiat 124 Spider
2006 Corvette
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Re: Cam wheel torque

Post by 18Fiatsandcounting »

aj81spider wrote:Just a note of caution on checking the torque of an impact wrench on lug nuts.
I totally agree. My suggestion above (and I should have stated this) was to start out at very low settings and move up, not the other way around. In other words, use your impact wrench to "test tighten" a lug nut to 10 ft lbs and then slowly move up. You should be able to feel or hear if the impact wrench starts to really crank on that lug nut for whatever reason. After some time, you can likely find an air pressure and wrench setting that gives a fairly reliable desired torque. The number of pulses from the wrench might be important too, so I'd use a consistent time (3 seconds?).

And yes, I always torque my lug nuts with a torque wrench. Habit I guess, as I had too many friends who took their car in for service and an overzealous shop technician broke or stripped something with an impact wrench. :(

-Bryan
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Re: Cam wheel torque

Post by SteinOnkel »

tima01864 wrote:That will work,. The torque on that bolt is massive. Wish I could borrow it.
Not really. On most cars the cam bolts get torqued to 120+ ft lbs. Crank bolt on I4 VWs is 180 ft lbs + 1/2 rotation w/ loctite, so quit your belly-aching :D

Put it into Reverse, all 4 on the ground and pull the handbrake as far as it will go. That should help. Might be enough to get it to 87. If not belt & vice grips.

Impact wrench seems a great way to snap the camshaft, I wouldn't recommend it.
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Re: Cam wheel torque

Post by tima01864 »

My lug bolts require 85lbs, Alloys bought from a tire store owne, That was his suggestion. I always use a torque wrench and step up 10lbs at a time.
Putting the car in reverse with the hand brake, No not a good idea. The timing belt would slip with all that torque on the cam sprocket.
I have given up on the impact wrench, Would of been great, No need to take the belt off again. Damn belt is so tight to get on.
A guy at work let me use a heavy duty belt wrench like the one AJ pointed to. Except it is rubber. Will see how that goes, If not I will go for the chain type. Damn
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Re: Cam wheel torque

Post by SteinOnkel »

tima01864 wrote:My lug bolts require 85lbs, Alloys bought from a tire store owne, That was his suggestion. I always use a torque wrench and step up 10lbs at a time.
Putting the car in reverse with the hand brake, No not a good idea. The timing belt would slip with all that torque on the cam sprocket.
I have given up on the impact wrench, Would of been great, No need to take the belt off again. Damn belt is so tight to get on.
A guy at work let me use a heavy duty belt wrench like the one AJ pointed to. Except it is rubber. Will see how that goes, If not I will go for the chain type. Damn
Use the old belt for this. Then swap the belt again, which doesn't require you to touch the cam bolt.

"Damn belt is so tight to get on."

You sure you got the right one? There are two different ones. I had no issue getting my timing belt on and off.
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Re: Cam wheel torque

Post by tima01864 »

After the build belt became tight to the max of tension release.I have read at least one post of this happening. I was told by the builder it happens sometimes lol. Maybe because I used an MLS head gasket?The gasket was sold as 1/16th thick. I think the belt for a 2L is 148 teeth. I could use 149
I did try using the engine as a brake, The wheel just slipped over the teeth of the belt, I was careful, Not wanting to do any more damage.
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Re: Cam wheel torque

Post by 18Fiatsandcounting »

I can't speak to the timing belt issue as my replacement belts have all gone on pretty easily, with the tensioner ending up roughly in the middle of its travel.

But, my only advice here: Definitely do not try to torque your cam pulley bolt when the (new) belt is slipping in and out of the grooves. Very likely to damage the belt. An old timing belt that you don't care about: fine. A new belt that you hope will last the next 25,000 miles: no.

-Bryan
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