where would you even drill and tap for 8 pressure sensors lol

 

It's already drilled and tapped! Glow plugs! I guess that's what the lol is for...

 

GLOW PLUGS!!! great idea :thumb:

 

I know some old hot rodders that know how to calculate cylinder pressures but I haven't ever been able to wrap my head around everything involved to do the calculations.

 

The glow plug holes will work, but what amount of pressure does a stock file make? That would be where I'd start and work my way up. Or just go until something gets thrown out the side.

There are also so many material differences to account or as well, like density of rods, pistons, pins, caps, etc.. You are putting in parts that are more than capable of killing the rotating assembly. But, doing this test will give you a better shot at keeping it together.

 

Right. I know there is equipment that uses the glow plug holes and will monitor cylinder pressure. A nearby shop has some but only for Duramax trucks. It won't work with the powerstroke. The only place I know of that has this capability is Swamps and they won't offer that service unless I am running their products, since they don't have crap for 6.0 parts that is not happening either.

I know it will not guarantee that I don't throw a rod, but if we are able to monitor the cylinder pressure during the tuning process you can minimize spikes in pressure which should help relieve some stress on the rotating assembly.

 

The stock rods in the 6.0 have proven to be quite robust. Especially compared to the 6.4 or 6.7. What kind of power are you planning to put down that you are worried about your rods? 800 whp is nothing for the stock bottom end.

 

Mitch, I really wish i had your confidence in the stock bottom end. I really do. maybe it is just because it is a pretty expensive problem when it fails, but I want to be on the safe side. kdogg busted a rod when his truck hung a gear and over-revved and my build is going bigger on turbo and injectors than his set up. So some truck have windowed blocks at under 700 hp, but on the other hand, like the truck that just made 863 with 205s and spray, some trucks are making well over 800 on stock rods. A few guys have pushed the stock rods to 1000 hp before they started bending so I don't know.

I guess I am just a little worried because I don't want to be putting new rods in for a little bit.

 

Adam, mine broke a wrist pin and grabbed the piston, pulled it down where it went below the cylinder and pushed its way out the bottom. The crank end of it was fine. The rod end was boogered up but all still there, it just pushed through the wrist pin.

But, he is right some will live and some won't. I assume your truck is your dd so you are probably not going to hammer on it at every red light. But, who can resist with that much on tap.

I would say go for it checking the pressures if you can find someway to do it. what range of sensor would you use(100k psi?) This stuff is what this site needs besides the threads on high idles and zoodads. You may want to give Mike at MPD a call, they seems to be into all this more advanced stuff alot and may give you some advice.

 

I just laugh, you want a 800+ compound big fuel setup but scared to window the block... stick with moderate size injectors and a mediocre single if you want to play nice! All kidding aside I know plenty of people who've made "gape my hole" on mild setups, not all trucks/engines are created equally!

 

...not all trucks/engines are created equally!

I have to agree with Greg on this one. Just because Kdogg's engine came apart at some power level/cylinder pressure at some given rpm, doesn't mean that yours or mine will even if you do all of the datalogging. I think most will agree that mid to upper 600s for hp is probably pretty safe as long as the motor doesn't see that sort of power all the time. I would suggest just picking a power level that you would be both comfortable and satisfied with and just tune it to that power. This isn't to say that idea of data-logging cylinder pressures is bad or a waste as I think it is a very good idea, but I just don't think the cost justifies it.

 

I am not "scared" of windowing the block. If it happens it happens. That is how it goes and I have an excuse to upgrade. Some engines will live fine at high power levels and some won't. If mine is one that will only hold 600 hp because of some casting inconsistency or something, then no amount of monitoring cylinder pressures or advanced tuning is going to save it. Nor is there anyway to predict, much less prevent, fluke events that cause some engines to fail. Obviously, anyone who modifies their truck knows that and is accepting that risk.

Whether or not I can find cylinder pressure monitoring equipment will not change how I proceed with my build. I started this thread because I am pretty tired of us 6.0 guys living in the stone ages, and apparently being content with that. I am hoping to find more tools to continue to push the limits of performance with these trucks. How did Swamps put together a 7.3 that runs well over 700 hp on the stock bottom end? They used a plethora of tools, including cylinder pressure monitoring, to refine their tuning to make more power with less stress on the engine. Any of you who live in the upper midwest should take some time to visit Duramax Tuner and Cummins Tuner in Northern IL. They have some incredibly sophisticated equipment, seriously their 4wd dyno is sweet, and they are constantly pushing the limits of performance with those trucks. But, in the 6.0 world, we seem to be content to just get it close enough and call it a day. I figure cylinder pressure monitoring would be another tool to help tuners push these trucks further.

 

This is true. I agree Adam. I guess it is hard to determine the intent of the threads like these sometimes. Either way I think it is a GREAT discussion and I agree that the only way to push the envelope with these motors is by thinking of new ways to do stuff. Obviously they aren't as straight forward to build and make power with as a common rail setup is. So I for one welcome and thank the ideas of this discussion.

 

You guys may be right, in my specific case, monitoring the cylinder pressures may not be worth the cost. Either way, I think it could be very useful in developing the tuning for these trucks. From what I have been learning about cylinder pressures lately, data-logging them can tell you an absolute ton about what the engine is doing. For example, you can tell exactly how long the delay is from start of injection to start of combustion, something that tuners have to guess at now. Another fun fact, using higher Cetane fuel actually lowers cylinder pressures and increases power output. Interesting stuff.

 

Oh wow. Now that's cool. Man if you can figure out that much then not only would it help tuning but it would help injector sizing and building too, such as how much time is available for getting fuel shot into the cylinders so an optimally sized nozzle can be used for a give injector body capacity.

 

That is true. I was also reading a couple of online articles in some scientific journals, this was like last week I think, about Diesel engines in the future using cylinder pressure sensors as part of the engine control system, specifically to meet stricter emissions requirements. Obviously that is outside the realm of possibility for these engines but that kind of illustrates how useful cylinder pressure data can be.

 

Really makes you wonder if high boost is a head gasket killer. I guarantee the explosion during combustion makes more than 34ish psi.

As far as using it for tuning, if Holley can make a PCM for their injection systems that self learn, sct could incorporate something like that into the tuning. Where you get a file and have an input board to plug external sensors in and it really dials in the tune. Then reload it after the process is done. That how live tuning is done, making changes on the fly, then saving them.

 

The current vw diesels have pressure sensors in the glow plug as one unit.