Pics of what will cause camshaft failure
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- scenarioL113
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- Joined: May 31st, '08, 09:00
- Location: Massapequa Park, NY
Pics of what will cause camshaft failure
A lucky stab with the magnet into my oil pan retrieved this woodruff key that ran through my front gears inside the timing cover. The next time you read through your cummins books and it says "be careful........catastrophic engine damage will.......yada yada yada...! Well now you are seeing the result first hand.
When I first pulled it out I thought it was a broken gear but on further examination I could see the shape of the woodruff key on one of the ends. It got pressed into the shape of the gears.
When I first pulled it out I thought it was a broken gear but on further examination I could see the shape of the woodruff key on one of the ends. It got pressed into the shape of the gears.
Last edited by scenarioL113 on Aug 15th, '10, 20:45, edited 1 time in total.
1971 28 Bertram
4BT Cummins
Frank
9-11-01 NEVER FORGET
4BT Cummins
Frank
9-11-01 NEVER FORGET
- Harry Babb
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- Location: Fairhope Al
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Ouch! ! !
It would cost a fortune to make a part like the damaged key.
What kind of injection pump do you have on your engines? I am assuming that the key came from the "Pump Drive"....right???
The key must have been laying on a ledge of some kind.....then fell into the gears.....once a part like that makes it to the oil pan its not a problem.
At any rate it make a cool trinket.....but most of all I am glad that it did not damage anything else and that you are back up and running......
No bent valves?????
hb
It would cost a fortune to make a part like the damaged key.
What kind of injection pump do you have on your engines? I am assuming that the key came from the "Pump Drive"....right???
The key must have been laying on a ledge of some kind.....then fell into the gears.....once a part like that makes it to the oil pan its not a problem.
At any rate it make a cool trinket.....but most of all I am glad that it did not damage anything else and that you are back up and running......
No bent valves?????
hb
hb
- scenarioL113
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- Joined: May 31st, '08, 09:00
- Location: Massapequa Park, NY
It was from the Lucas-Cav Injection pump. I am up and running and I checked as well as I could without pulling the head.
No obvious bent valves, I measured the height with rockers removed and all of them sat as close to identical as could be measured. I had no acess to air so I did not pressurize the cylinder.
It is running pretty good but I can only get 2600 rpm on either engine when before I was getting just shy of 2800. This all started with a leaky pump and when I tried to fix I messed up the calibration. I brought it to a shop and they replaced gasket and adjusted governor spring but did not calibrate it.
This all means nothing, I could still have a slightly bent valve I really dont know. No push rods were bent so who knows its running pretty good.
Still cruises at 2400 and over 18knots and no smoke.
No obvious bent valves, I measured the height with rockers removed and all of them sat as close to identical as could be measured. I had no acess to air so I did not pressurize the cylinder.
It is running pretty good but I can only get 2600 rpm on either engine when before I was getting just shy of 2800. This all started with a leaky pump and when I tried to fix I messed up the calibration. I brought it to a shop and they replaced gasket and adjusted governor spring but did not calibrate it.
This all means nothing, I could still have a slightly bent valve I really dont know. No push rods were bent so who knows its running pretty good.
Still cruises at 2400 and over 18knots and no smoke.
1971 28 Bertram
4BT Cummins
Frank
9-11-01 NEVER FORGET
4BT Cummins
Frank
9-11-01 NEVER FORGET
- Harry Babb
- Senior Member
- Posts: 2354
- Joined: Jun 30th, '06, 21:45
- Location: Fairhope Al
- Contact:
Frank
Just for grins and giggles you can remove the air filter, make sure that the fuel is in the STOP position, then spin the engine over while listening in the intake.
If an intake valve is not sealing properly you will hear a distinct "HISSING" noise every time the piston goes thru a compression stroke.
You can do the same for exhaust but you would have to remove the pipe from the turbo.
Not real sientific....but it is a good indicator.
hb
Just for grins and giggles you can remove the air filter, make sure that the fuel is in the STOP position, then spin the engine over while listening in the intake.
If an intake valve is not sealing properly you will hear a distinct "HISSING" noise every time the piston goes thru a compression stroke.
You can do the same for exhaust but you would have to remove the pipe from the turbo.
Not real sientific....but it is a good indicator.
hb
hb
I would do a cylinder leak down test just to be sure. If there is a slight bend or cantor to the valve to where its not sitting 100% in the seat, it could start to burn.
Make sure each throttle is reaching 100% wot. You can do this at the dock by checking the stops on the pumps.
Harry,
You could possibly hear leakage past the rings doing that test and mistake it for leaky valves.
Make sure each throttle is reaching 100% wot. You can do this at the dock by checking the stops on the pumps.
Harry,
You could possibly hear leakage past the rings doing that test and mistake it for leaky valves.
- Harry Babb
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I can see what you are saying, I have successfully found burnt or leaking valves before using my unscientific method.....its easier on diesels because the compression is much higher making the hissing much louder....Bruce wrote:Harry,
You could possibly hear leakage past the rings doing that test and mistake it for leaky valves.
The old Mack truck engines....711, 673 and the 675 have 2 heads and their V-8 have 4 heads....its a dead give away to pull the intake and the exhaust then spin the little bugger over....real easy to figure out which head to pull.
If Frank has a leaking valve it will not take long for it to show its ugly face in all its splendor.....
hb
hb
- scenarioL113
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