Put your CR Pressure Relief Valves back in!

Soup Nazi

Soup Nazi

The artist formerly known as Don M
Joined
Sep 26, 2006
Messages
1,197
If you have a pressure relief valve block kit, please remove it, blow on it three times and toss it in the trash can. They were solution to a problem, but the cure is much worse than the disease.

The system needs a valve to relieve huge pressure spikes that occur when the throttle is lifted quickly. The problem is only worse with larger injectors.

FCA duty cycle is higher with larger injectors to keep the target pressure where commanded. Dual pumps, modified puumps, etc all add to the problem, but are not needed to destroy the injectors when no valve is used.

We have seen solenoids exploded off the top of the injectors, nozzles blown apart, cracked injectors, etc. Nearly all this is attributed to the valves being removed from a system that can spike pressures past 60,000 PSI.

We have purchased a "bursting module" with pressure capabilities past 4000 bar ( 58,000 psi ) to do research and development on high pressure common rail fuel components. We can fail parts here at will.

Put em back in or buy injectors, nozzles and parts constantly.
 
I never did recommend closing the exit. Actually I have been a critic of many with capped rails. I guess if you have enough money to buy a bucket of injectors it's alright, but it's quite a sacrifice for a minimal gain.
You want more fuel pressure? It's coming. Cummins/Bosch has a system in the works that operates nearer to 30,000.
 
Snedge said:
I never did recommend closing the exit. Actually I have been a critic of many with capped rails. I guess if you have enough money to buy a bucket of injectors it's alright, but it's quite a sacrifice for a minimal gain.
You want more fuel pressure? It's coming. Cummins/Bosch has a system in the works that operates nearer to 30,000.
Click to expand...

You mean a new RV set closer to 30K?
 
What about the dual feed line, I am thinking that this would be ok?? or am I in a dream land?
 
Don, or ANYBODY else with a little fab and engineering know how... Let's examine the problem. The premise is sound, uncontrolled pressure spikes causing carnage. Makes sense.

Ok then what to do about it? Putting the stock relief back in makes little sense since they go south so fast. Then for cost the price of an injector to replace. Then as pointed out above, folks with dual feed lines or, like me, use Dual Pumps and feed the rail from two places. Evil twins setup does this too...

So, is there a skilled soul out there that can fab a proper relief valve that doesn't cost a mortgage payment and will last more than a half dozen cycles before getting weak? Or forward thinking enough to solve the dual feed issue?

C'mon, this is compD! someone can solve this!
 
morkable said:
What about the dual feed line, I am thinking that this would be ok?? or am I in a dream land?
Click to expand...

Im guessing since the dual feed line goes where the PRV is suppose to be, I would say no. But Im not the expert. I was just about to order a rail cap...
 
i just had injectors and cp3 put in mine at industrials shop and they told me i needed a cap should i put a valve back in?
 
I shimed mine with the same size shim like in the ppe kit for the dmaxes and I just had a local machine shop make me a "T" block to scerw into the rail so I can have my feed line and relief valve in place
 
Would capping the rail have anything to do with all these melted CR pistons lately?

Just a thought from a Ford guy.
 
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