Broken rod due to oil overfill
05-14-2007, 06:15 AM
#21
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Originally Posted by Billman250,May 13 2007, 05:31 PM
I have a customer here, which I am thinking may have oil hydrolocked. We were running the Dragon, and he was blowing lots of smoke on turns. From what I gather, he was 1/2 qt overfill.
The small end of the connecting rod broke off around the wrist pin. The wrist pin is still in the piston.
The rod also broke at the big end. The rod cap and the bearing are flawless. There is definitely NO oil starvation at the crank.
There is no sign of the rod seizing on the small end either.
It was not raining.
So the big question is, does anyone think 1/2 qt overfull of oil could cause enough oil to enter the cylinder to lock it? Or perhaps 1 qt overfill?
All I have right now it the parts I pulled out of the #1 cyl hole with the head off.
Lets discuss, and I'll post some money pics
The small end of the connecting rod broke off around the wrist pin. The wrist pin is still in the piston.
The rod also broke at the big end. The rod cap and the bearing are flawless. There is definitely NO oil starvation at the crank.
There is no sign of the rod seizing on the small end either.
It was not raining.
So the big question is, does anyone think 1/2 qt overfull of oil could cause enough oil to enter the cylinder to lock it? Or perhaps 1 qt overfill?
All I have right now it the parts I pulled out of the #1 cyl hole with the head off.
Lets discuss, and I'll post some money pics
05-14-2007, 07:56 AM
#22
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I don't think we are asking the right questions here.
I think the big question is if the PCV is capable of supplying enough oil to the intake to hydrolock the engine. If the answer is yes, then I think it is most certainly possible.
Another question I have is this. Given just a slight overfill, would that really cause more oil to be up by the PCV? The oil is pumped there in a given amount. I don't see the overfill having much to do with anything. Unless we are talking over fill to the point were the oil is actually making it back into the oil channels and toward the head by itself. Then there would be signs before a hydro lock through the intake.
I think the big question is if the PCV is capable of supplying enough oil to the intake to hydrolock the engine. If the answer is yes, then I think it is most certainly possible.
Another question I have is this. Given just a slight overfill, would that really cause more oil to be up by the PCV? The oil is pumped there in a given amount. I don't see the overfill having much to do with anything. Unless we are talking over fill to the point were the oil is actually making it back into the oil channels and toward the head by itself. Then there would be signs before a hydro lock through the intake.
05-14-2007, 08:57 AM
#23
I also don't think 1/2qt over would do this, I've run 1/2qt over for years in my B series cars for track days and regular driving until the next change and never had a problem, I doubt the F series would have such a failure with just 1/2qt over. I could see a bad HG leak causing enough oil to enter the chamber to possible cause a problem, but it would be getting burned up for the most part so not even sure about that.. somehow it sounds like a fairly large amount of oil entered a combustion chamber in an EXTREMELY fast period of time to cause this before ignition..
05-14-2007, 09:29 AM
#24
Could have just been a flawed or cracked rod that was installed as OEM. No doubt this would be a rare occurance but "S/ happens"". The rings would be the weakest point in the chain and if the rings survived, I would suspect a bad rod.
05-14-2007, 10:16 AM
#25
Originally Posted by JackS,May 14 2007, 12:29 PM
Could have just been a flawed or cracked rod that was installed as OEM. No doubt this would be a rare occurance but "S/ happens"". The rings would be the weakest point in the chain and if the rings survived, I would suspect a bad rod.
05-14-2007, 10:37 AM
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Subscribed. I usually put in about 5.5 quarts of oil for an oil change, and sometimes I add in oil every now and then since my car burns a bit of oil. I think a regular oil change with filter should be 5.2quarts according to the manual, so I'm always about 1/2 quart more.
05-14-2007, 10:42 AM
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Everyone is saying it was smoking like crazy on the over fill. Is it black smoke coming out the exhuast or is it coming from under the hood? Is it normal on WOT for a little black smoke to exit the exhuast?
05-14-2007, 11:03 AM
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Originally Posted by Kenpo_S2000,May 14 2007, 01:42 PM
Everyone is saying it was smoking like crazy on the over fill. Is it black smoke coming out the exhuast or is it coming from under the hood? Is it normal on WOT for a little black smoke to exit the exhuast?
05-14-2007, 11:42 AM
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Originally Posted by Jsmply,May 14 2007, 11:03 AM
Do you have any kind of engine management mods? A VAFC or something? The smoke they are talking about in this thread is probably white smoke. If you are seeing black smoke, that is most likely a fuel issue. Excess fuel not being burned off properly. The term is usually "running rich." That is why I asked if you had any engine management mods that are not listed in your signature. If so you might want to get on a dyno and see what your A/F ratio looks like.
05-14-2007, 11:45 AM
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Originally Posted by Kenpo_S2000,May 14 2007, 11:42 AM
No other mods than what is listed in my sig. I am running a test pipe and getting a cell I believe from that. One code is for the 02 sensor the other says it is running rich. I just want to make sure I nothing to worry about. The exhaust has no resonators at all just the test pipe, straight pipes, and then the dual hks. My brother told me he saw a little black smoke shoot out when i revved it up.