WHAT IS BENIFIT FROM FUEL X OVER AND OIL X OVER KITS FROM CLAY
WES

 

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.

 

I had never heard of the FRX (But do have Clay's HPX) and am interested in hearing if anyone can tell me what the FRX will do and if you truely noticed a difference.

 

Riffraffs' site, explains, what the benefits are. I installed both to my ride, and noticed a great decrease in motor noise/cackle.

 

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.....

 

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......

 

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

 

Really new here, so I could be wrong, but I don't think your description as I read it is not 100% correct. My understanding is the #8 cylinder is oil deprived as the #6 fires right before it. The oil pressure is what tells the injector to fire, the #8 Long Lead injector takes a double sip of fuel to compensate for the oil pressure issues. But since the #6 fires right before #8 the oil pressure is a little low and can lead to problems with #8 injector.

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.

 

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.

 

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.

 

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.

 

It also gives an exit for the air in the fuel. Instead of said air being forced through the injectors which is no good for em.

 

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.

 

Removing the check valves sends the same volume of oil to each head simultaneously and thus the equalization. It is as if there is only one outlet that then tees to each head. This does not increase pressure. The pressure is increased by the IPR (Injector Pressure Regulator), commanded by the PCM, to allow a larger volume of oil to reach the oil rails and hence the injectors.

 

so if putting both HPX AND frx, would you have to replace #8, or not , just so i would know if this was nessasery.


al