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Broken Valve Spring 453

Started by XMartin, April 14, 2017, 11:23:42 AM

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XMartin

I took the rocker cover off this morning, and found a broken valve spring. First I noticed a spring piece nestled on top of a keeper, then noticed a different keeper that had popped out and could tell that the spring had broken underneath it.  This engine is pouring white smoke when it is running and blowing oil out of the exhaust.  The air box also has alot of oil in it.  I have been reading posts about white smoke, and one of the things mentioned is seals on the blower.  Would a broken valve spring cause the smoke, or is this just another problem that needs attention?
I tried to post pictures, but they were not accepted because of the wrong file type.
Any thoughts are appreciated!

bushmechanic

Hate to be the bearer of bad news but your engine has "dropped a valve". More often than not the cylinder head is busted up and possibly took out the liner and piston of the affected cylinder. You might as well pull off the head and have a look, I'm sure it won't be good. Good luck!

mike_belben

Call mike @RCS diesel in ludlow mass. they specialize in detroits, can mail out a reman monday morning.

1 413-589-9976
Praise The Lord

coxy

Quote from: bushmechanic on April 14, 2017, 01:18:19 PM
Hate to be the bearer of bad news but your engine has "dropped a valve". More often than not the cylinder head is busted up and possibly took out the liner and piston of the affected cylinder. You might as well pull off the head and have a look, I'm sure it won't be good. Good luck!
x2 had the same thing happen

dgdrls

Did the valve drop out of the head?
Fingers crossed the damage is minimal.

D


BargeMonkey

 I read this when it was first posted and went, keeper+spring, where is valve ? 😂 did it actually drop the valve and you hear a real bad clicking and banging noise ? Hard to diagnose over the computer but welcome to teardown time. I went thru a similar situatio . With my 353 5yrs ago and had to put a remanned head on. This is probably the best time to tear it down completely and go thru it, they really aren't that bad to do, parts aren't to bad. Hassinger diesel in PA has that engine on the floor on a pallet ready to ship. 👍

XMartin

Wow, Thanks for all your replies!
I feel a little sheepish about this, but it is not a broken valve spring. The broken spring  is a push rod spring.  I don't know if the retaining clip failed first or the spring broke, forcing the keeper out of the pocket.  I was able to talk to Detroit mechanic at Leid Deisel, in Thorp, which is about 30 miles away. I had 'Harold' on the phone while I was looking at the top of the head.  He told me that if the snap ring groove in the pocket is bad, the head is bad.  Makes perfect sense to me, not the best news, but a definite course of action.  Take the head off.  I drained the coolant last night, but again, it is raining with lightning right now, so it looks like it will be Monday before I get back into it. Once I have the head off I will be able to tell if there is an issue with a bent rod, and maybe see if there are obvious  issues with the cylinders.  Lots of oil in the air box. I have a good feeling about Harold, he sounded knowledgeable about Detroits. I wasn't planning on a major overhaul, but it may be the way to go.

snowstorm

I had the same thing happen with a 671. Snap ring groove was worn snap ring came out. It made the engine sound uneven. I uses a wore out cut off wheel on a die grinder. In under a min a new groove.  I ran that motor for another 10 yrs

Spartan

White usually means coolant.  What can happen is you engine can blow water up the exhaust and when it mixes with your soot, looks like oil.  When you take the head off.
If you have a cylinder that is fairly clean of carbon but you have white crust in there, you have coolant burning.  That pressure alone can blow your liner seals and get water in the airbox.
I just had to replace my head, I had cracks in between 6 of the 8 pairs of exhaust valves.  If you can't see cracks visibly, take the head to a machine shop and have them pressure check it.  Mine I am now sure was due to me wanting to quiet my exhaust down a bit, which I think put too much back pressure and fried my head.  School of hard knocks for me lately :'(.

Check your cam on the lobe where the spring broke too.

XMartin

Thanks for the thoughts.
I don't see any evidence of coolant, no tiny spots of green anywhere, the engine oil is a dark black, no hint of milkiness. 
The idea of grinding a new slot for a snap ring sounds interesting, I may try it. 
The sun is out, I think I'll give it a go, and just tarp everything up when the rain starts again.

sandhills

I agree with Spartan, check the cam lobe on the bad cylinder, hope it works out well for you.

XMartin

Well, I got the head off, whew! That thing is HEAVY. The lifter rollers and the cam look great on all four cylinders.  What surprised me was that a different cylinder's piston top has a heavy black bumpy carbon deposit on it.  I think that cylinder must not have been firing. Bad injector?  All the cylinder walls are not scored but do look like they are glazed.  Three piston tops had a circle of light brown spots about 3/4 of an inch each in diameter, I guess they correspond to the injector spray pattern. About then, it got dark with storm clouds and started to rain. I dumped fresh oil on the cam to rinse the rain off and covered the whole thing up until the sun shines again.
I plan to sneak out to the shop tomorrow morning before the company shows up to clean the head up and start to disassemble it. I have worked on gas engines before this, but I am surprised how small the valves are on this thing. Why not two bigger valves?

A mechanic told me a long time ago to figure out what is wrong with an engine before I tore it down, this time I found a problem telling me not to run it any longer, but I'm still not sure what the heavy white smoke was coming from.

XMartin


Yippee, I finally was successful in posting a picture. This shows the broken spring retainer, (the one in the far right.  A piece of the broken spring is nestled on top of another retainer about in the middle of the picture.

snowstorm

you didnt have to take the head off to regrind the snap ring groove. i didnt 

XMartin

snostorm,
I had not thought of grinding the groove out, you mentioned in a post that I had not read before removing the head.  I don't regret taking it off.  The push rod had been banging around in there long enough to wear the locknut round. Seeing that I am concerned where the filings went and what other damage they caused.
It also let me see the carboned up piston top, and the glaze in the cylinders. Right now I,m leaning towards new liners, or if the cylinder walls clean up, new rings.

teakwood

National Stihl Timbersports Champion Costa Rica 2018

dgdrls

Same thought teakwood

For those of us who don't get inside a Detroit but once in a blue moon
some photos of the liners and pistons if and when you pull them would be great.

best
D



XMartin

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I took the head apart, and took some pictures. The one showing on the post so far shows the wear on the pushrod, the square on the rod and the nut are worn round.
these others show wear on the valve tappets and injector.
The bore of the affected spring shows wear from the broken spring rubbing.



 

coxy

what are you going to do with the extra power you will have after the rebuild

Spartan

that injector rocker looks pretty wore

did you figure out the oil in exhaust?  Blower?  Rings?

XMartin

Spartan, I just don't know, I'm not at all familiar with these engines.  From what I've read, I think I'll redo the blower, and a cylinder set.  I am going to talk to Mr. Leid about the whole project when I show him the head and it's running gear.  I have done tractor engines so I know some procedures, but this is a different animal altogether.
Coxy, I just got the machine,so I haven't run it, but around the shed.  My cousin had 434 in a Oliver tractor, and when he hit a low spot that screaming meanie would seem to really bog down.  I was never impressed with the engine. Maybe he had it in a gear where it was doing all the work you could expect from it. 

coxy

they will bog real quick if the rpms drop just a little in to high of a gear

Logger RK

With the white smoke,I would guess cracked head and it's burning anti freeze. Bogging down was probly running it in  to high a gear. It's a 2 stroke motor so it's needs high RPM's to get the most power out of them.

dgdrls

based on what you found so far the white smoke  could be the result of the carboned cylinder/piston. Bad injector or low compression (mis-fire) will cause white smoke.

mike_belben

Praise The Lord

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