what would cause the vavle train to break

[MCH86GN]

On the drivers side of my engine, the drive train broke. Meaning the shaft that has the rockers on it broke in half. This is the first time I have really had this car out and running it since 2009. There was no knock, just a sudden snap and I removed the valve cover the find the shaft snapped. I did look down at the "lifter" and one was not on center. Could it have popped out and jammed the rod in that position and broke the shaft. The oil pressure went really low. Now I'm at a cross roads, do I buy a block and rebuild or try and fix this? I already have a std/std polished crank and block shouldn't cost too much. I can then get billet mains and forged pistons, or should I take option 3 and sale the car because I'm getting really fed up with things breaking on a car with mild bolt ons.

 

[Chuck Leeper]

A broken rocker shaft is not uncommon. Do a search... Frequently discussed.
The loss of oil psi could be the lifter has popped out of the bore. Also not usually a fatal occurrence.
Before you go ballistic, check it all out. Could be a simple fix........

 

[MCH86GN]

A broken rocker shaft is not uncommon. Do a search... Frequently discussed.
The loss of oil psi could be the lifter has popped out of the bore. Also not usually a fatal occurrence.
Before you go ballistic, check it all out. Could be a simple fix........

Well that appears to be exactly what happened. I will take it apart and look. What causes it to break? All I did was lay into the throttle and was at 13psi of boost.

 

[MCH86GN]

A broken rocker shaft is not uncommon. Do a search... Frequently discussed.
The loss of oil psi could be the lifter has popped out of the bore. Also not usually a fatal occurrence.
Before you go ballistic, check it all out. Could be a simple fix........

Assuming I haven't damaged anything else, is there a replacement better than stock?

 

[aminga]

http://www.taperformance.com/proddetail.asp?prod=TA_1316-231-2

 

[MCH86GN]

http://www.taperformance.com/proddetail.asp?prod=TA_1316-231-2

Thanks, you have been a lot of help. Once I get the intake off and check it out and replace the lifter, is there any good way to see if the cam is damaged? It is the first lifter on the driver's side. I also have to worry about having driven it with very low oil pressure. I hope I didn't damage anything else. I'm wondering if I should seriously consider a rebuilt. The short block in my car is not the original and the mileage on it was unknown. There are a lot of unknowns with this short block and do I keep spending money on it or start fresh. I have a crank already, std/std and polished.

I guess I will take it one step at a time. Might post pictures tomorrow, if it is of any value.

 

[thadeal4real]

Go with option 3 sell it to me cheap

 

[MCH86GN]

Well, I got the intake off and I'm not sure when I pulled the intake if it seated the lifter back in the bore, but it was back in. I did pull the lifter and there is no damage to it, nor to the pushrod. So I have a theory as to what happened. Two years ago I sent my short block to Aggressive to have them put my heads and intake on, because I was not confident enough to do it and I also had to have them reset the cam sensor. Ok I get my fully built engine home and in a bone-head move I tried with 3 men to lift the stand out of the back of the truck. Well I held on, the man on my right held on and the man on left did not pay attention that some type of fluid was on that part of the stand and it slipped out of his hands and my engine fell, because it was top heavy it rotated when it was falling, about 6', and landed on the driver's side valve cover. My wife was standing near and it missed her foot by mere inches, thank god it did not land on her foot! Anyway it destroyed the valve cover and the valve cover was crushed right on the valve train. I never thought to inspect the valve train after that. My theory is the valve train was broken or damaged and this past week is the first time in 2 years that I have really pushed the car and a tap into the throttle and it finally gave. Now this is my theory and how the lifter got seated, I think it happened when I pulled the intake. I found no pieces of metal in the valley, there was a little coolant and gas, but that could have happened when I pulled the hoses and coolant and gas spilled on the intake and I pulled the intake at an angle and I could hear fluids pouring so I grabbed a shop towels and cleaned off the intake. I also found several throttle cable clips on my intake, there is where all the clips popped off and went to. I believe this was a ticking time bomb and would have happened sooner or later. Probably on my first or second run at the track.

Now, is there anyway to test this before I put it back together. I was thinking of first changing the oil. If I were to put replace the valve train, and change the oil and filter would it be advisable to turn over the engine and make sure the lifter is working okay were it was unseated?

Any advise on how to proceed from here is greatly appreciated. Especially on how to check and see if the there is damage to the camshaft.

Thanks,
Charles

 

[SHADOWII]

The prudent thing to do would be first check the oil filter(cut-open) and oil pan for debris, i.e, bearing material, metal from the rocker shaft,etc. If no bearing material, (You were blessed!) If brg damage, you could start by removing caps or just pull the eng. and do the rebuild! ouch!
You may have just lost the use of the #1 cyl. in which case, also check for a smell of gas in the oil in case you were getting raw fuel in the cylinder and washing off the cyl. walls. Rotate the eng to check for lobe damage, bent push rod, broken valve spring, etc. If all seems well, replace the rocker shafts, button her up and take a compression check and hit the road!

 

[MCH86GN]

The prudent thing to do would be first check the oil filter(cut-open) and oil pan for debris, i.e, bearing material, metal from the rocker shaft,etc. If no bearing material, (You were blessed!) If brg damage, you could start by removing caps or just pull the eng. and do the rebuild! ouch!
You may have just lost the use of the #1 cyl. in which case, also check for a smell of gas in the oil in case you were getting raw fuel in the cylinder and washing off the cyl. walls. Rotate the eng to check for lobe damage, bent push rod, broken valve spring, etc. If all seems well, replace the rocker shafts, button her up and take a compression check and hit the road!

When you say rotate, you mean rotate the crank manually. Also, can I remove the oil pan without lifting the engine? I also did retrieve the broken parts of the valve train. One bad thing, I drove the car until I was safe from traffic. With very low oil pressure.
So it sounds like a good inspection of the engine is due. I didn't want to have to do this, but I think I need to send it back out to aggressive and have Bruce take a look at it.

If my engine survived this, it will be a miracle. Meaning no rebuild.

 

[MCH86GN]

The prudent thing to do would be first check the oil filter(cut-open) and oil pan for debris, i.e, bearing material, metal from the rocker shaft,etc. If no bearing material, (You were blessed!) If brg damage, you could start by removing caps or just pull the eng. and do the rebuild! ouch!
You may have just lost the use of the #1 cyl. in which case, also check for a smell of gas in the oil in case you were getting raw fuel in the cylinder and washing off the cyl. walls. Rotate the eng to check for lobe damage, bent push rod, broken valve spring, etc. If all seems well, replace the rocker shafts, button her up and take a compression check and hit the road!

Since this is the drivers side, would there be any value in removing head. If there is fuel in the cylinder, couldn't be cleaned and a thin coat of oil put on it? Or remove the valve spring and allow the cylinder to evaporate any fuel.

 

[Rafs-T-Type]

I wouldn't expect any major damage from a rocker shaft breaking. If you go the TA shaft route (which is a solid route), I would pair it with the RJC rocker shaft supports - http://rjcracing.com/product/rocker-shaft-supports/. The you shouldn't have to worry about the shaft again.

 

[MCH86GN]

I wouldn't expect any major damage from a rocker shaft breaking. If you go the TA shaft route (which is a solid route), I would pair it with the RJC rocker shaft supports - http://rjcracing.com/product/rocker-shaft-supports/. The you shouldn't have to worry about the shaft again.

My major concern, is I was in Detroit when a the ticking noise I had been hearing and was told was normally jumped an order of magnitude. I kept driving until I was safe and could call a flatbed. So I had to drive a few miles with metal parts, maybe circulating through my oiling system and 20psi oil pressure or lower. Like I said, I was able to pull the intake and I see no visible damage whatsoever. I'm going to try and do a post-mortam as well as I can. Remove the oil filter and collect any contents in the filter and then remove the oil pan and see what in there. Then do a visual inspection of the bearings. What about fuel setting in a cylinder. Supposing I fixed the everything and I turned the car over for about 30 seconds will that get oil through system? I also have already removed the coolant from the car, no oil or gas as far as I could tell. I have looked a the oil dipstick and it does not appear that there is any coolant in the oil. Now I did spill gas on the intake and when I lifted some went down in the valley.
Like I said, no bent pushrods, nor damaged lifters. I think I broke the valve train when I dumped my engine two years ago. I complete destroyed valve cover and it landed right where the valve train broke. I believe the bolt had sheered at that point and it was just a matter of time before the rocker broke. My thoughts are the valve train broke and the lifter was shot out of the very first bore on the drivers side.

Just because I don't have my car in a climate controlled garage, I put a little oil on the rods lifters and in the valve train. Don't want anything to rust while I'm waiting on parts.

 

[MCH86GN]

I wouldn't expect any major damage from a rocker shaft breaking. If you go the TA shaft route (which is a solid route), I would pair it with the RJC rocker shaft supports - http://rjcracing.com/product/rocker-shaft-supports/. The you shouldn't have to worry about the shaft again.

What about replacing the springs. Our buddy bison has stressed to me many times about having good springs. Bison any advise?

 

[MCH86GN]

I the oil pan and filter off. There is some debris covering the screen for the oil uptake I will take a picture it. As I matter of fact I will photo everything and get opinions. Once I drained the oil, I pour fresh on in the valley and on the train and turn the engine over a few times. As far as I can tell no bent rods, no bearings in the oil and I may be fortunate this time and no have mechanically destroyed another engine. One good thing, if i do buy after market valve train and rcokets even if the is something wrong with the block that money will not be wasted. These would be all parts, I thin I could keep on the heads for a rebuild.

 

[SHADOWII]

If there was any major damage, you wouldn't have been able to drive very far. Any potential for damage would have been the fuel thinning out the oil and passing thru the eng.

 

[Rafs-T-Type]

I tried to limp home when my shaft broke. I made it a few miles. When it broke though it was just that, a broken shaft so there wasn't really any metal bits to speak of.

 

[MCH86GN]

Here is a picture of the crank and bearings. I trying uploading all the pictures in one post and it didn't like it.

 

[MCH86GN]

This is a picture of the oil screen, it originally had a glob of stuff, not all metal some soft material as well. I believe this was in part causing the oil pressure to be low, along with the lifter unseated.

 

[MCH86GN]

Grinding into the valve cover from the driving I had to do.

Just a picture of the rocker arm that was broke.