After seeing several recent threads and having a couple of side discussions with a few folks, I have a question about the long-term impact of this HPX mod.

First, let me start by saying that all the versions I've either seen myself or seen pictures of end up allowing the hose/tubing to dip down between the heads, thereby creating a low spot in the line.

Since the goal of this mod is to create a pressure balance between the heads, I assume that there really is not very much oil movement from one head to the other except for the small amount required to balance the pulses from injector firing sequences. If this assumption is correct, I have a couple of questions....

1) Is the low spot in the HPX line sitting there and getting slow-baked by the engine heat and eventually building up sludgy crud?

2) If the crud is being formed, should we remove this line and clean it out periodically (like every 20,000 miles or so)?

3) Forgive me for this question, but I can't visualize the hose/tubing routing very well at the moment - so is there a way to potentially route the hose/tubing so that it creats a "self-draining" scenario, thereby letting heavy particles (that could turn into sludge) drizzle down into the heads between engine runs?

4) If #3 is a possibility, would that "self-draining" scenario allow the residual engine heat in the valley to slow-bake the thin layer of oily residue inside the tube and thereby allow another form of crud buildup and eventually make it ineffective?


See where I'm coming from here? If we have created a low spot and sludge DOES build up, then we should probably clean it out periodically before the line becomes plugged and ends up being ineffective.

Last question....

5) Am I thinking too much about something that really isn't an issue?

 

All good points to ask Pete, since I haven't done this mod but was thinking of it, I'd like to hear what people have to say.

 

I see where you are going Pete. But, the lines don't drain when the engine is turned off. By the amount of oil/fuel I had in my cylinders after the injector change. I also think if the oil is draining out of the lines, there is a problem. I don't know how often the oil changes out in the line. In other words, how fast it is replaced with fresh oil while running down the road.

Good question.

 

We had the same thoughts Pete and came to the conclusion that we would build ours so that it didn't dip into the engine valley. So when the engine is off the oil could slowly drain down during the oil change. We don't know if "baking" is an issue but we decided to engineer around it just incase. Very good points Pete, thanks

 

where's Gene when you need him... we need to know the lineal travel distance between the two head ports every time the cycles pulse from injector firing sequences. I bet he already has the volumetric oil consumption per firing event, at least for stock injectors, which is the point where all the calculations have to start. That would end up telling us whether the oil really does or does not completely crossover from side to side.

 

Well, Rick, I understand what you're saying, and "draining back down" is probably a bad way of stating my concern - I've edited the questions accordingly for new posters/readers. It might be that any sludgy "heavies" may drizzle down a downward sloped hose/tube and not get captured. With a low spot, like on mine, there is simply no way that can happen. Another wonderment I have is whether or not on initial startup the initial oil pressures push the oil through the hose.

 

I'm with you on this Pete. I have the SS line that has the big bends in it. I wish there was a way of knowing how often the oil is changed out of the line. I guess this will be another like the HPOP oil change thread.

 

I hadn't thought about THAT one in a looonnnngggg time.

I hope we don't start seeing any or or or or .

If we do, then I'll have to take it like a man....

 

. I don't think it will be like that. Things that make you go .

 

I don't think it gets hot enough to bake anything at all in the engine valley like that.
The cylinder heads themselves are the hottest point where oil contacts engine parts, save the turbo bearings.
Leaving the turbo out of this discussion, the area immediately surrounding the exhaust port gets the greatest amount of heat.
Examination of the area underneath the valve covers reveals no appreciable crusty stuff building up on a diesel engine.
Gassers run much higher EGTs and even those are pretty clean inside.
.
Pete I understand your concerns, but in the case of a diesel engine, they just don't build up crud like that. The oil just gets more and more loaded with soot, but in my experience, it never really settles out.

 

Hopefully, there aren't any "sludgy heavies" at all to be captured, 'cause the only way for oil to get out of there is THROUGH the injectors.

Pop

 

I am not sure you can build one without the dip, the dip is needed to clear the turbo.

 

The oil won't "slowly drain down during the oil change" at all. The high pressure lines and galleries don't get changed during an oil change, just as the HPOP reservoir doesn't get changed.

But let's not start THAT conversation again.......

Pop

 

Excellent input from a mechanic's experience. Thanks, Dan.


I also hope, and don;t suspect, that there wouldn't be any real "heavies" because of the oil filter(s), especially where bypass systems are in service.


That's what I was thinking, too, but just couldn't visualize everything well enough to remember.



Good input, guys. I'm feeling better about this situation already.

 

Pete, I think the only way any of that gets started is when Tenn. Mike gets involved in this discussion.