Smarty Jr. Is being added to scrap truck part pile!!

[mpaulson]

My altitude while towing is between 1970 ft and 3610 ft. I did fine before the Smarty and don't want to give up the way the brake works with the ecm/tcm, I love this part of the truck since I tow more than 50 % of my time.

 

[zzman]

Same thing here with the head gasket. First one was replaced last December, 5 months later out again. I too had the studs put in.
I'm not fixing it this time. Traded it in on Monday for a 2011 3500 C&C with auto tran.
The smarty jr w/ME is up for sale or sail if no one wants it.

I guess I need to change my signature now.

 

[CBlack]

Wouldn't he loose his exhaust brake?



Nick

Yes. But some say it's worth it to have a better turbo and limit the drive pressure issues.

Yes, and I know the S400 is popular with the street/strip crowd but I haven't heard it being used in too many towing applications. It's a pretty big turbo to spool with a load.

I know of several people (down south) that tow with a S400 (466 up to a 475) that tow with no issues. And this charger is on an otherwise stock truck.



The 6. 7 flows so much air that a large charger, at close to sea level, will spool easily.

 

[Bob4x4]

It's not just the Smarty- I have replaced hgs on H/s programmed trucks too

 

[CBlack]

There is more to it than the programmer being used.

There are two diesel shops I know of in Houston that stopped selling Smarty's a few years ago because they swore that it was the cause of HG failure. They switched to H&S only and claim to have had zero issues.

I've spoken to a well known and respected shop who, in my opinion, is a guru on the 6. 7s and he says the VGT is the culprit.

 

[mpaulson]

From what some of my online research has found is that instead of an ideal 1:1 drive pressure to boost ratio, this turbo runs at 2:1 or worse. Craig at NADP said the same thing. They sell a bolt on waste gate kit for $900 something. Some of the kits route the vented exhaust back into the intake, and some run the vent pipe down to after the turbo and you have to weld on a fitting to the exhaust pipe. I think I would go the route to post turbo, why would anyone want to run the exhaust into the intake? This is one of the reasons for the delete in the first place.

I guess I may have to consider one of these. $$$#@$%!

 

[seafish]

Glacier Diesel sells an add-on waste gate kit for the 6. 7 exhasut manifold and VGT turbo that is extremely well designed and manufactured.



http://www.glacierdieselpower.com/product.aspx?pf_id=PG67-38MM-7510

 

[AH64ID]

The HE351 on the 5. 9 is also capable of 2:1, and the HG's don't blow on the 5. 9. It's something to do with the 6. 7 and the high DP to boost ratio.

 

[mpaulson]

Most of what I read on the waste gates is that most guys set them up for 32 psi. My thoughts are that if I go back to the Edge, I never broke the 30 psi anyway, so would it even open up? I kind of think not. My normal high psi's were about 26-27, so the drive pressure wouldn't get into the danger zone, hence why for the first 170,000 Kms, I had no problem. Just since adding the Smarty, the boost easily hits 33 psi on a simple hill climb.
The head gasket on the 6. 7's gets too narrow between the cylinders and they added more hole to it that are too close the the cylinders, so they fail way easier than the 5. 9's.

 

[Regcabguy]

It's not just the Smarty- I have replaced hgs on H/s programmed trucks too

Yep. Pablo's replaced two on a 6. 7 w/H&S programming. Special gasket,machined head and studs this time around. Owner's going to try EFI this time around.

 

[cerberusiam]

The boost is not the issue, the VGT slamming shut and the DP spikes along with the 6. 7 design seem to be the biggest issues. The DP really has nothing to do with the problem, but the results of of too much fuel and the dead air drive the cylinder temps to the point where the head warps more that it should. Loose the VGT and the probem generally disappears from that aspect, but, it is an inherent problem with the 6. 7 design that requires some extra work to address.

My guess is the head work was not adequate to fix the real problem, if any was done at all. Once the HG goes the head MUST be resurfaced and the tolerances have be much tighter than normal. If a standard resurface is a 30 on whatever scale is used that has to be taken down to something like a 15. There is too much disparity in the expansion rates of the head and the block between the siamesed cylinders. All tolerances and standards need to be adjusted tighter once you go away from stock fueling. Then the VGT ends up being the problem and a WG on the EGR circuit is almost mandatory.

Either leave the engine stock or be prepared to spend $$ addressing the short comings of adding power. Might as well o-ring the head and get it very straight, use a high $$ gasket, and plan on studs or it will be an ongoing problem.

 

[mpaulson]

The boost is not the issue, the VGT slamming shut and the DP spikes along with the 6. 7 design seem to be the biggest issues. The DP really has nothing to do with the problem, but the results of of too much fuel and the dead air drive the cylinder temps to the point where the head warps more that it should. Loose the VGT and the probem generally disappears from that aspect, but, it is an inherent problem with the 6. 7 design that requires some extra work to address.
My guess is the head work was not adequate to fix the real problem, if any was done at all. Once the HG goes the head MUST be resurfaced and the tolerances have be much tighter than normal. If a standard resurface is a 30 on whatever scale is used that has to be taken down to something like a 15. There is too much disparity in the expansion rates of the head and the block between the siamesed cylinders. All tolerances and standards need to be adjusted tighter once you go away from stock fueling. Then the VGT ends up being the problem and a WG on the EGR circuit is almost mandatory.

Either leave the engine stock or be prepared to spend $$ addressing the short comings of adding power. Might as well o-ring the head and get it very straight, use a high $$ gasket, and plan on studs or it will be an ongoing problem.

So the pressure spike would be vented off with a waste gate added in? Or actually not because it is the boost pressure that opens it and when you let off the fuel, the boost drops at the same time, so the waste gate wouldn't help the spike issue. Or are some designed to be set up to vent when the drive pressure hit whatever you have it set for?

 

[cerberusiam]

Most of the designs vent from drive pressure to stop the spikes that back exhaust into the cylinders. The programming tries to hold boost to a slowee drop for emisisons but under additional fueling the operation is too fast for the equipment. Remember, lifting off the throttle does not chop fueling on a CR, it is stepping that down. With high DP and boost dropping there is simply too much fuel for the air and cylinder temps sky rocket. The engine can take it but the head is water cooled all around while the cylinders are not so there is differential in the heat transference that cause unequal movements. Under normal operation the vent is not needed but rapid throttle closing under power does cause some bad spikes to DP on a VGT turbo. By design the EGR was there to handle that but blocking it threw a monkey wrench into the design.

The DP is definitely not the only issue. The gasket creep between cylinders is a problem and if you work the truck with any programmer it is going to happen. The design parmaeters are very tight on the 6. 7. No longer do these engines have massive overhead for power. Sometime several little things cause bigger issues. If the head is off might as well o-ring it and be done, along with as smooth and level of maching than can be done.

 

[Matt_L]

What are you using to monitor your EGT's and boost?



Not saying this is part of your problem, but if you're using a device like a Edge Insight it reads from the factory MAP and not its own boost sensor.

Maybe you're making way more boost than you think?

Also if you are running one of these devices you should hook up a drive pressure gauge for yourself. This way you'll know for sure if DP is your problem or if its something else.



Not too many H. G issues once studs are installed unless you never had your head "decked" and it isn't true anymore...

 

[S.Morris]

Taking off the egr removes the failsafe relief back to intake. At this point an external waste gate would/ could be set to your chosen limit.



Was the head ever retorqued after a few hot cold cycles on initial install of studs?

 

[cerberusiam]

Not too many H. G issues once studs are installed ...

By the amount of reported problems, not true. As the OP has found out, once you pop it the problem persists. Not as many as there was a couple years ago because there are fixes, but, head studs will not stop the problem like it did on the 5. 9's.

 

[mpaulson]

Taking off the egr removes the failsafe relief back to intake. At this point an external waste gate would/ could be set to your chosen limit.

Was the head ever retorqued after a few hot cold cycles on initial install of studs?

No, they were not retorqued. And it is a new set of ARP studs going in again this time because the mechanic messed some up removing them. I read a few post online about retorqueing them, how often does this happen? It's a fair bit of labour to get back in to the studs to do this. I guess I may have to pay them to do this. I get the truck back on Monday, and I'm heading out with the trailer on Wednesday afternoon already for a 600 km round trip. That should be enough of a heat and cool cycle to do the job and I could get the truck back in after that to do the retorque.
My EGT'S are read though the Edge Juice monitor, but with a pyrometer is in the manifold that I put in, so that's not reading off of oem sensors. The boost is reading off the oem sensors. On Monday when I get the truck back I'm switching back the the Edge instead of the Smarty since I ran the Edge for the first 170,000kms with no problems and I can tow my RV and run between 15-22 psi normally compared to the Smarty which had me in the 24-30 range all the time and up to 33 psi on climbs which obviously has been creating too much drive pressure.
The head was not decked last time, but this time it is done. Looks like I may need to look into the waste gate and I will plumb it tips as I have read online to use the drive pressure instead of boost to activate it so that the drive is directly controlled and I'll set it for about 40-45 psi of drive pressure. This will allow about 28 psi of boost going by what others have said their number worked out to with on the Glacier units. Then again, I think to myself, I did the 170,000 Kms without a problem because I wasn't hitting the high boost levels, maybe I'll be fine after I switch back to the Edge I'll be fine. This way I can save my money and put it towards the repairs that I have already done!
On the note of retorqueing the head bolts, isn't their a different torque spec for "new" stud as opposed to reusing stud that have already been torque? Does this not take care of it? They never get redone on new vehicles.

 

[RVTRKN]

It should have been recommended at the time of install, studs or not, you need to re-torque the heads after HG replacement. Its not like its a factory new engine, if you are stock you can get away with it, but in your case its a must. Even if they haven't loosened, its a good insurance plan.

 

[AHarris]

My truck has plenty of power stock. I think I'll just leave mine alone and see if I can get her to 400K.

 

[Bob4x4]

By the amount of reported problems, not true. As the OP has found out, once you pop it the problem persists. Not as many as there was a couple years ago because there are fixes, but, head studs will not stop the problem like it did on the 5. 9's.

There is a pretty big list building on H&S facebook post on all the 6. 7 hg failures both with and w/out studs