CROSS OVER KITS
Postmaster
Joined: Jan 2009
Posts: 2,667
Likes: 1
From: Glen Rose,Texas
The oil crossover is for equally feeding oil to the #8 injector.#8 is robbed of oil and does not get the same as the others and leads to that injector going bad early.
The FRX is used to get air free fuel to the injectors at the same pressure.
I have the crossover and waiting for the updated version of the FRX.
The FRX is used to get air free fuel to the injectors at the same pressure.
I have the crossover and waiting for the updated version of the FRX.
Cargo Master
Joined: Mar 2008
Posts: 2,975
Likes: 19
From: Archdale,N.C.
If I remember correctly,the HPX(oil crossover) balances out the pressure of the oil rails,the PCM can only read the pressure from one side,so connecting them together via the HPX,it gets a better/more precise reading,it definitely smoothed out the idle on mine,if I'm not right yall can yell at me.As for the FRX(fuel rail crossover),I haven't done that yet so i can't give any info other than repeating what Clays website says.....
you can't fix stupid!
Joined: Mar 2008
Posts: 1,906
Likes: 2
The oil crossover is for equally feeding oil to the #8 injector.#8 is robbed of oil and does not get the same as the others and leads to that injector going bad early.
The FRX is used to get air free fuel to the injectors at the same pressure.
I have the crossover and waiting for the updated version of the FRX.
The FRX is used to get air free fuel to the injectors at the same pressure.
I have the crossover and waiting for the updated version of the FRX.
Cargo Master
Joined: May 2010
Posts: 3,047
Likes: 10
From: Snohomish, WA
I just put on the Riffraff Diesel FRx, I did a post on the new design and also posted some data on the improvements from it.
New FRx from Riffraff Diesel
New FRx from Riffraff Diesel
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Senior User
Joined: Oct 2010
Posts: 407
Likes: 2
From: Mobile, AL
the #8 injector is robbed of fuel not oil pressure. the oil crossover balances the oil pressure between the 2 heads and evens out the pressure spikes. the regulated return or frx you guys refer to does help get air out but it feeds the injectors uniformly and eliminates the need for the long lead injector that requires less fuel to operate......
The HPx does even out pressures across the heads, and allows #8 to get a little more pressure.
This is in no way an attack, I'm learning here...I am engaged with Chris in an ongoing PSD system discussion in this thread https://www.ford-trucks.com/forums/1...operation.html
My comments are based on our discussions, so if something is amiss please let me know. I want to learn here, nothing more.
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Cargo Master
Joined: May 2010
Posts: 3,047
Likes: 10
From: Snohomish, WA
The HPx and the FRx or RR both help combat the firing of #6 just before #8. The oil in the head has a pretty good amount of volume, but can loose pressure when #6 fires. The HPx is a pretty small diameter line, so it does not provide a bunch of volume. It does allow for the heads to be interconnected which keeps the pressure more stable.
The FRx also eliminates the dead head issue which helps the firing order issues and the cackle. By creating a flow of fuel that moves air bubbles induced by the fuel system through the heads, the air is pushed back to the tank instead of going through the injectors.
The FRx also eliminates the dead head issue which helps the firing order issues and the cackle. By creating a flow of fuel that moves air bubbles induced by the fuel system through the heads, the air is pushed back to the tank instead of going through the injectors.
Cargo Master
Joined: Apr 2009
Posts: 2,135
Likes: 0
From: Man Cave
Didn't notice any difference with the oil X over but noticed a BIG difference with the fuel X over. The cackle has gone. btw mine are from another supplier. I have helped a M8 install Clays fuel X over and it was a breeze and is a quality product.
Post Fiend
Joined: Nov 2007
Posts: 9,549
Likes: 14
From: Payson, AZ
The FRx or other FUEL cross connect kits are for eliminating the dead end fuel rail of each head. Due to the firing order the #8 sees the most significant improvement in fueling and operates much quieter because of the increase in fuel supply. The FUEL cross connect kits have nothing to do with oil supply to the injectors.
Senior User
Joined: Oct 2010
Posts: 407
Likes: 2
From: Mobile, AL
Completely understand the fuel and oil systems are self contained. If I understand this correctly, the oil pressure is used by the injector to fire the fuel. Since #6 goes right before #8, the oil pressure is somewhat diminished. Allowing equalization across the heads is an attempt to remedy the oil situation.
Due to the firing order, and a similar system layout, the #8 is also somewhat fuel deprived. The regulated return attempts to address that issue. It also allows the air in the fuel to go somewhere other than thru the injector.
The crossovers mods, either oil or fuel, are similar in design due to the similarities in the systems (and therefore their respective deficiencies) for which they are designed. Yes? No?
Robin- in a separate thread you posted that removing the check valves in the HPOP outlets can address the oil pressure issues. How does that work? By simply increasing the overall pressure in the rails so #8 sees better pressures? How does that affect the #1 and #2 injectors, since they would see higher pressures?
Thanks for the education.
Due to the firing order, and a similar system layout, the #8 is also somewhat fuel deprived. The regulated return attempts to address that issue. It also allows the air in the fuel to go somewhere other than thru the injector.
The crossovers mods, either oil or fuel, are similar in design due to the similarities in the systems (and therefore their respective deficiencies) for which they are designed. Yes? No?
Robin- in a separate thread you posted that removing the check valves in the HPOP outlets can address the oil pressure issues. How does that work? By simply increasing the overall pressure in the rails so #8 sees better pressures? How does that affect the #1 and #2 injectors, since they would see higher pressures?
Thanks for the education.
Post Fiend
Joined: Nov 2007
Posts: 9,549
Likes: 14
From: Payson, AZ
Completely understand the fuel and oil systems are self contained. If I understand this correctly, the oil pressure is used by the injector to fire the fuel. Since #6 goes right before #8, the oil pressure is somewhat diminished. Allowing equalization across the heads is an attempt to remedy the oil situation.
Due to the firing order, and a similar system layout, the #8 is also somewhat fuel deprived. The regulated return attempts to address that issue. It also allows the air in the fuel to go somewhere other than thru the injector.
The crossovers mods, either oil or fuel, are similar in design due to the similarities in the systems (and therefore their respective deficiencies) for which they are designed. Yes? No?
Robin- in a separate thread you posted that removing the check valves in the HPOP outlets can address the oil pressure issues. How does that work? By simply increasing the overall pressure in the rails so #8 sees better pressures? How does that affect the #1 and #2 injectors, since they would see higher pressures?
Thanks for the education.
Due to the firing order, and a similar system layout, the #8 is also somewhat fuel deprived. The regulated return attempts to address that issue. It also allows the air in the fuel to go somewhere other than thru the injector.
The crossovers mods, either oil or fuel, are similar in design due to the similarities in the systems (and therefore their respective deficiencies) for which they are designed. Yes? No?
Robin- in a separate thread you posted that removing the check valves in the HPOP outlets can address the oil pressure issues. How does that work? By simply increasing the overall pressure in the rails so #8 sees better pressures? How does that affect the #1 and #2 injectors, since they would see higher pressures?
Thanks for the education.
