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Old 06-11-2012, 09:26 AM   #1
28 fast faton
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Default Engine knock

I have an engine knock that I think might be the cam gear. When I put the timing pin into the hole while it is running it has a bit of a wobble(ie the pin moves in and out slightly) My questions are 1. will this cause a knock and 2. How does it come to wobble when I know the cam nut is tight and the spring is new and 3. if I leave it will it damage anything or should I replace it. Thanks guys
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Old 06-11-2012, 09:38 AM   #2
Mikeinnj
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Default Re: Engine knock

Did you put grease on the new spring ? If not it can cause a knock. The pin will go in and out as the pin depresses into the TDC mark indentation on the gear.
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Old 06-11-2012, 09:41 AM   #3
Aerocraft
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Default Re: Engine knock

A loose timing gear will cause a knock. Since you have a question about wobble in the gear, I suggest that you open the engine up and take a look. It is easy to remove the cover for the timing gear. If the gear is loose, eventually it will fail. Gar Williams
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Old 06-11-2012, 11:25 AM   #4
28 fast faton
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Default Re: Engine knock

I have already tightened the cam nut and I do realize the pin goes in and out of the TDC hole, but there is still a wobble and one of the books I have said to check for wobble. I don t know how a wobble could come about if it was tight.
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Old 06-11-2012, 11:35 AM   #5
jkeesey
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Default Re: Engine knock

How did you tighten the cam nut? With one of the specific sockets or a chisel like some folks would use? And I was always told to never push the timing pin into the cam gear while running because it can wreck the fiber gear. The best way to see wobble would be to remove the side cover and run the engine and watch the gear if it wobbles then with the engine off try to gently pry it back and forth and see if it has any play.
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Old 06-11-2012, 01:32 PM   #6
Bob C
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Default Re: Engine knock

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If your timing gear has a metal center and fiber gear they sometimes come apart.

Bob
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Old 06-11-2012, 02:13 PM   #7
George Miller
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Default Re: Engine knock

Timing gear should not run out.
1=timing gear loose.
2=some thing is keeping it from going against the cam flange flat.
3=metal center in cam gear is loose in the fiber. Never use one with a metal center.

The only way to tell for sure is to take the cover off.
Is this a old cam gear, did you just work on the timing gear?
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Old 06-11-2012, 02:36 PM   #8
jan bogert
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Default Re: Engine knock

Bob C is correct. my timming gear was knocking also. i started the motor and inserted the timming pin, knock went away. the timming gear was two piece, and the outter part was loose, it would have come apart if left alone.
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Old 06-11-2012, 06:21 PM   #9
28 fast faton
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Default Re: Engine knock

I read that if it is knocking to tighten the cam nut. I had to buy a new cam nut because someone had beat the hell out of the old one and install it with the cam wrench. I tightened it as much as I could but after re assembling I realized it wobbled. I am not sure if it had a metal centre or not. Will the wobble hurt it if I drive it for the summer.
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Old 06-11-2012, 06:31 PM   #10
Tom Wesenberg
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Default Re: Engine knock

I'm helping my friend with the same noise right now ay Oshkosh. I just pulled the side cover put the pickup in high gear and rocked it back and forth. Sure enough you could see the play between the aluminum center and fiber gear. Tomorrow we'll finish changing to a one piece gear.
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Old 06-11-2012, 06:42 PM   #11
George Miller
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Default Re: Engine knock

Quote:
Originally Posted by 28 fast faton View Post
I read that if it is knocking to tighten the cam nut. I had to buy a new cam nut because someone had beat the hell out of the old one and install it with the cam wrench. I tightened it as much as I could but after re assembling I realized it wobbled. I am not sure if it had a metal centre or not. Will the wobble hurt it if I drive it for the summer.
It takes a lot of torque to make it tight some where around 100 ft lbs. That would be a 100lb weight on the end of a foot bar. That is a lot of torque.
So the nut is not tight or you have a steel center on a fiber gear. Either way it needs to be fixed.
Gear wobble is not good, your gear teeth will not mesh right.
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Old 06-11-2012, 08:49 PM   #12
Kohnke Rebabbitting
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Default Re: Engine knock

If you try to use the cam nut to force the gear on, most often one of the dowels will hang up, and no mater how tight you pull the nut, the dowel digs in to the fiber gear and will not be at a 90 degree to the cam.

The easy way is stand the cam on end, on a block of wood, and may be cement, or anything that won't give you two ups, for one down, dowels up, and line up the gear with the dowel pins. Then make a thick wall pipe, about 6 inches long, with a I.D. so that it clears the threads on the cam. the wall thickness about 3/8's or so.

Use a heavy hammer on the thick wall pipe, and tap the gear down to the thrust on the cam, making sure that the gear goes on right, and nothing shears off, and goes between the gear, and flange.

The cam threads should be clean and dry, and also the nut, put some, thread locker on, and the nut on.

I use a 5 inch Jawed vice, and lead lined , and put the cam gear side ways in the vice, tighten the cam nut, and give the Z- Ford wrench a crack with a hamer, and I have never had on come loose, ever.
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Old 06-11-2012, 09:18 PM   #13
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Default Re: Engine knock

Could it be that the two index pins were not in perfect alignment when you tightened the cam nut? That could easily account for the wobble when the nut is tight. It is my suggestion that you remove the cam gear to throughly investigate the problem. Gar Williams
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