Broken Rings on a 06 5.9

[AH64ID]

You need to swap that 180° thermostat out for a 200° one. Your OEM thermostat is a 190° unit and you don't want the bypass being your main thermostat.

IMHO Fleece puts a 180° in them for racing applications and DD or towing applications need a 200° thermostat.

 

[Bob4x4]

Here is a link to the coolant flow http://forum.mopar1973man.com/index.php?/topic/1306-coolant-pressureflow/

 

[darkhorse_05]

Sorry for the long time it took me to reply fellas. But, Thanks for the link Bob. AH where do I find a 200* thermostat for this application?? Im really not looking forward to swapping them out, its in the best location. lol

 

[Tuesdak]

So the cylinder walls were "spotless" with the broken rings?

 

[AH64ID]

Sorry for the long time it took me to reply fellas. But, Thanks for the link Bob. AH where do I find a 200* thermostat for this application?? Im really not looking forward to swapping them out, its in the best location. lol

I would stop by NAPA and ask for a 195 or 200° thermostat for a SBC.

So the cylinder walls were "spotless" with the broken rings?

There wasn't any noticeable cylinder wall damage. It did get 0.5mm oversize pistons anyways thou.

 

[JLight]

My sons 24v broke no 1 piston rings and scored the daylights out of the wall. its sleeve time.

 

[Wayne M.]

In general, I always thought detonation broke rings. Fact it happened on 1&6 which are companion cylinders is very interesting. I also believed that the first to happen in a hi combustion temp situation on these engines, was that the valve seats drop.
I never studied how the injectors are fired. Are they sequential, batch fired etc? I do think something was going on to break the rings and that the rings just didn't break due to quality.
I'm totally with the run of the mill trucks running long. That's why mines totally stock except the extra filter.
Since the engine is being blueprinted, I'm wondering how far off the original balance job was?

 

[cerberusiam]

Unless you put gas in the tank detonation is not going to be an issue. Diesel doesn't detonate like gas because I won't separate into vapor easily. Ring breakage is due to high cylinder pressures, typically from excessive timing or excess fuel. The design of the rings is stoic rich to reduce cylinder pressures so everything is engineered to that end. Sometime sit doesn't take much at the right time and they break. Risk that is run whenever stock is departed from.

 

[DonFitzwater]

In general, I always thought detonation broke rings. Fact it happened on 1&6 which are companion cylinders is very interesting. I also believed that the first to happen in a hi combustion temp situation on these engines, was that the valve seats drop.
I never studied how the injectors are fired. Are they sequential, batch fired etc? I do think something was going on to break the rings and that the rings just didn't break due to quality.
I'm totally with the run of the mill trucks running long. That's why mines totally stock except the extra filter.
Since the engine is being blueprinted, I'm wondering how far off the original balance job was?

Wayne, it's been my experience that the CR engines typically drop valve seats due to extreme temperature spikes in the combustion chamber. Steady temperature changes not so much. The seats expand and contract at a slightly different rate than the surrounding head and that's how they drop a seat.

 

[AH64ID]

OEM balance jobs are never blueprint quality. There is always a marked improvement in balance with an aftermarket one off job.

I don't think detonation is an issue on diesel.

Now that I have been keeping an eye out for them I am seeing more ring issues on the 06-07 trucks than before. There still aren't lots but there are enough to wonder if something changed in the ring design/build/etc for 06-07. Stock or modified it doesn't seem to matter.

Valve seats have issues from high EGT's not combustion temps, and yes there is a difference. The stock 04.5 will have low combustion temps and high EGT's where a modified and properly timed 04.5 will have higher combustion temps but lower EGT's, so the valve seats actually see less abuse on a properly timed engine than a stock one. This is a big part of the reason for the valve seat change in 04.5.

 

[cerberusiam]

Extreme temp spikes are the norm with diesel engines, that is not going to affect valves or seats. It the constant high temps and EGT's across the seat that cause them to fail, and pistons also. The valve and seat spec changed 3 times over 3 years of production to handle the higher temps. Pretty sure the seat clearance in the head was tightened also as it was a bit loose originally and that was causing them to drop under hard use. The head expanded faster than the seat so tighten the clearances a bit and the issue was resolved.

 

[Wayne M.]

But why 1&6? I think it's more than coincidence.

 

[cerberusiam]

Cylinders 1 and 6 have the most extremes on about everything from air to cooling, would expect them to see the highest problem rates. Been a lot of seats in the other cylinders fail also so it is not restricted to just 2 cylinders.

 

[AH64ID]

Cylinders 1 and 6 have the most extremes on about everything from air to cooling, would expect them to see the highest problem rates. Been a lot of seats in the other cylinders fail also so it is not restricted to just 2 cylinders.

Agree, 1&6 seem to have higher failure rates than others. I think 4 comes in next on the HPCR's with the design of the exhaust manifold.

 

[TCDiesel]

Its just simply heat and tolerance, We run 2200F for 15 to 18 seconds during pulls making 1700+hp, and during off season we freshen up the engines, we rarely find broken rings, The hole spec's are extremely lose. Some think that EGTs are telling you cylinder temps, EGTs should be use as a touchtone to actual cylinder temps, Tuning also plays a big part of cylinder failures in all HPCR engines. all that heat has to go somewhere if your tuning is pushing it into the piston you are going to be replacing pistons and rings often..If you are pushing it into the head valve problems. Choose you tuner wisely, and tune for you application, box tunes make power but they come with additional repairs and maintenance.

1 and 6 just don't have the cooling ports the rest motor is expose to, bypassing helps for the extremes ,that's about it.

 

[Wayne M.]

So did we ever come up with a solid conclusion on what happened to the Gentlemans engine?

 

[promisedland]

Its just simply heat and tolerance, We run 2200F for 15 to 18 seconds during pulls making 1700+hp, and during off season we freshen up the engines, we rarely find broken rings, The hole spec's are extremely lose. Some think that EGTs are telling you cylinder temps, EGTs should be use as a touchtone to actual cylinder temps, Tuning also plays a big part of cylinder failures in all HPCR engines. all that heat has to go somewhere if your tuning is pushing it into the piston you are going to be replacing pistons and rings often..If you are pushing it into the head valve problems. Choose you tuner wisely, and tune for you application, box tunes make power but they come with additional repairs and maintenance.

So custom tuning can be a help?

I have intrist in UDC [UDC-PRO is coming!]
Also HP tuners has a good thing going!

 

[TCDiesel]

Yep......... look at all the blown head gaskets on box tune 6.7. I don't think not 1 6.7 that had Edge box power head gasket survived.

 

[promisedland]

I was thinking about the 5.9L Cummins... any thoughts on these?
Any input as to why 'box' tunes take out piston rings and/or head gaskets?

 

[cerberusiam]

Too much timing is the usual problem. That drives cylinder pressure way up with fueling mods.