HPX crossover
Hook it, I'll pull it.
Joined: May 2007
Posts: 15,037
Likes: 4
From: Grand Lake, La.
#6 injector fires just before # 8. #6 takes the PSI from the #8 because the oil rail is only pumping to each head. With the HPX, it lets the oil from the HPOP flow through the HPX line from the other head and lets the #8 get the right psi to fire. This is what I thought. I can see this.
Not a liberal...
Joined: Jul 2006
Posts: 6,635
Likes: 4
From: Cut & Shoot, Texas
Well, I WOULD do it again. I put the SS HPX on from ITP Diesel, and it got a little quieter, but the engine smoothed out quite a bit. When it was stock it would bounce around in the engine bay at idle, and now it barely wiggles at all. Good mod in my book, and only a minor inconvenience when pulling the turbo.
My $0.02...
My $0.02...
Just my .02, just like Joe.
Posting Guru
Joined: Feb 2006
Posts: 1,459
Likes: 0
From: Wyoming
I have the rubber one from PDP (pure diesel power) had it for about 6 months now. Its high pressure hydralic hose. I thought it smoothed out my motor some, not a huge difference but worth 45 bucks.
Postmaster
Joined: Sep 2004
Posts: 3,916
Likes: 0
From: Bellingham, WA
Guess I will go with the minority here and say yes, I would do it again. I didn't see a major difference, but there was a difference for sure. Quieter idles, less knock. My wife even noted that on her first trip with it installed. I used the solid SS one from KCM and for the $45.00 buck I paid 3 years ago. Never a leak although I did replace the orings when I replaced the rest of the orings. I would steer clear of the flexible ones as many have had problems with them.
Post Fiend
Joined: Feb 2007
Posts: 14,541
Likes: 2
From: Dallas-Ft. Worth
#6 injector fires just before # 8. #6 takes the PSI from the #8 because the oil rail is only pumping to each head. With the HPX, it lets the oil from the HPOP flow through the HPX line from the other head and lets the #8 get the right psi to fire. This is what I thought. I can see this.
Next for me is to put on the fuel pressure gauge like Brandon's and shimming the FPR after I put in the Walbro pump. That will provide PLENTY of fuel volume, even with larger injectors that will follow.
you can't fix stupid!
Joined: Mar 2008
Posts: 1,906
Likes: 2
agreed^^^
the problem with #8 wasnt getting enough oil but not getting enough fuel...
i like my ITP hp x-over and would do it again and i dont have to take it out to get my turbo out. the itp hard line has a "dip" in it and you can pull your turbo out right through the "dip". atleast a stock one you can. joe is probably running something a tiny bit bigger. jmo.......
the problem with #8 wasnt getting enough oil but not getting enough fuel...
i like my ITP hp x-over and would do it again and i dont have to take it out to get my turbo out. the itp hard line has a "dip" in it and you can pull your turbo out right through the "dip". atleast a stock one you can. joe is probably running something a tiny bit bigger. jmo.......
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Hook it, I'll pull it.
Joined: May 2007
Posts: 15,037
Likes: 4
From: Grand Lake, La.
That's exactly right, but the issue was not the oil that I've ever heard -- it was fuel because of the dead-ended feed system. I understand the concept of what you're saying but the fix for the fuel situation is the RR or CCK (I have the CCK). If that's what the HPX does, I'm surprised I haven't heard that before. Besides, the fix for the HPOP petering out is to get a big (or medium) oil system, or go with SS/Hybrid injectors. They require less oil to fire, and inject more fuel with it.
Next for me is to put on the fuel pressure gauge like Brandon's and shimming the FPR after I put in the Walbro pump. That will provide PLENTY of fuel volume, even with larger injectors that will follow.
Next for me is to put on the fuel pressure gauge like Brandon's and shimming the FPR after I put in the Walbro pump. That will provide PLENTY of fuel volume, even with larger injectors that will follow.
agreed^^^
the problem with #8 wasnt getting enough oil but not getting enough fuel...
i like my ITP hp x-over and would do it again and i dont have to take it out to get my turbo out. the itp hard line has a "dip" in it and you can pull your turbo out right through the "dip". atleast a stock one you can. joe is probably running something a tiny bit bigger. jmo.......
the problem with #8 wasnt getting enough oil but not getting enough fuel...
i like my ITP hp x-over and would do it again and i dont have to take it out to get my turbo out. the itp hard line has a "dip" in it and you can pull your turbo out right through the "dip". atleast a stock one you can. joe is probably running something a tiny bit bigger. jmo.......
Hook it, I'll pull it.
Joined: May 2007
Posts: 15,037
Likes: 4
From: Grand Lake, La.
Well Hell, I guess I put the HPX on for the wrong reasons.
. I sure thought it was for the oil. 
Fleet Mechanic
Joined: Dec 2007
Posts: 1,766
Likes: 8
From: Hutchinson, KS
That's exactly right, but the issue was not the oil that I've ever heard -- it was fuel because of the dead-ended feed system. I understand the concept of what you're saying but the fix for the fuel situation is the RR or CCK (I have the CCK). If that's what the HPX does, I'm surprised I haven't heard that before. Besides, the fix for the HPOP petering out is to get a big (or medium) oil system, or go with SS/Hybrid injectors. They require less oil to fire, and inject more fuel with it.
As Izzy has said, it's a fuel thing on the #8. But isn't our fuel system ran by the oil provided in the rail? And as Joe said, the HPX equals out the pressure spikes between the heads giving way to a better pressurized oil rail per head because they are tied together. The #8 is also the furthest away from the HPOP hose going into the head. Not by much, but it's at the end. It's also at the end of the "deadend" fuel rail. Combine the 2 together, and then it's not performing like it could or should and struggling to keep up. By installing a HPX, you're getting better oil pressure to the back of the head so the injector can fire properly. Yes the deadend fuel rail is still present on a stock system, but a little more oil is there for the injector.
Granted, I'm NO expert and could be completely wrong!! Just going off of information I've read and heard.
That's my $.04 (I got a raise)
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