Performance Overflow Valve
 

Attached are some pictures. The spring is a mod'd - upgraded spring which will roughly double the fuel pressure of a turbo engine which should equal faster element filling.

Shipped CONUS ONLY. $40 each. I prefer only one (1) per customer so that the product will spread the word so to speak. These are already rebuilt and ready to go. It takes about 5 minutes to install.

To put this in perspective, many folks buy 5 to 6 cans of diesel purge per year which really doesn't do a whole bunch. For the same amount of money and a lot less time, you will feel a difference in your performance which is LASTING. I know because I have a tired 300D NA engine and I installed one of these and it made a very noticable difference in performance. I strongly suggest turbo OM617.9XX engines only.

I only have nine (9) left. A great deal of R&D went into these and the buyer should notice and appreciate that effort and effect.

Why do you suggest this for turbos only?

Pardon my ignorance, I've never heard of an overflow valve, where does it go?

It almost looks like the rack dampener

It will work with the 300D NA (I have one in my car). However, it's most or more noticable in the turbo. So, I guess I should have been a smidge more clear. My bad. In other words, it will work in your car also. I popped mine in about a month ago and it was noticable -- even for a 300D NA. I am targeting the turbo folks and mod'd turbo folks since it's a really nice upgrade.:D

Behind the IP, just follow the front-most line - banjo fitting. I will get a snappie tomorrow.

Got a message that my post was a little confusing. So, below will hopefully clear up things:

I am selling a total of 9 overflow valves. What is being offered for sale is one overflow valve for $40 shipped CONUS and I have 9 of those for sale.

Each valve is already re-built with one spring (mod'd spring).

Each valve consists of the banjo-like bolt, ball bearing, mod'd spring, copper washer, and end cap (the 5 pieces you see of the right in the 2nd picture).

I guess I should not have pictured all other 9 springs in the background. My bad. Let me know if I am still confusing ... lol

Found this on Google Images. It's letter "A" in the snappy. Hope this helps.

where do the springs go? I'm interested

The spring goes inside the body of the banjo-like bolt.

Each valve is already assembled, ready to be installed.

As for assembly, in goes the ball bearing, then spring, then copper washer, then end cap.

As a follow-up to more questions I received:

Yes, it works also on OM603 and OM606 engines. It works on N/A as well, but I suggest its application with turbo engines.

The spring is stainless spring steel, calculated for the Mercedes engines and fatigue tested.

With the spring (actually rebuilt valve) a turbo engine will get more fuel/power without modding the pump on a bench. (It works on a NA engine as well, but as I indicated, the most gains are felt on a turbo engine).

how much omf will I feel?Does it let more fuel in?How to send the money?

PayPal is preferred -- just like my injector service.

You will feel a difference. I felt it in my tired 300D NA engine. Of course your car will not be a Porsche, but it's a noticable performance upgrade.

Some folks with the 240D (4 cylinder engine) claim they run their engines without it and / or feel no difference. This is NOT for the 240D crowd. Further, by analogy, I have done a lot of injectors for folks and out of 100 sets, there's always 1 person who claims he felt really little to no difference. Of course the injectors before the R&R peed like crazy, weeped, and barely pushed any atomized fuel and with new nozzles no difference? So, the point I am trying to make is that yes, you will notice it and if you don't, then there's something else up with your engine. Hope the above, long winded response helped.

Did you have any measurements of fuel pressure with this vs. a normal 27mm spring?

I'm curious about this as well. It has been suggested by some who are very knowledgeable that OM606 knock/rattle/nailing is caused by insufficient element filling. This may be poor lift pump performance or low pressure due to the weakened regulator spring.

I am keeping close hold the specs. Obviously, one could meaure the PSI. I can say that the pressure is increased. However, it's not just simply adding a more robust spring to increase PSI. That is why I commented on the R&D aspect of this.

Right on. Sounds pretty cool. I'd try one.

http://www.peachparts.com/shopforum/diesel-discussion/234609-fuel-pressure-relief-valve-adjustment.html

Some related info on the most recent commentary

I did some pretesting with the valve a while ago.
My stock fuel pressure with OM617 Turbo engine was ~15psi. With the valve from Greazzer it did not fall below ~36psi....! http://www.superturbodiesel.com/std/...es/biggrin.gif

Gruß
Volker

More than 1.5 Years ago Funola was selling an Overflow/Pressure Relief Valve that was Adjustable.

I hope you have one next month,I'm on a fixed income,and can't afford this month.

Hi Greazzer,

I'll take one.

Peter

What was involved in the fatigue testing? I'm envisioning hooking up to a jig with a cam or actuator to compress the spring a couple million times while measuring the spring pressure and length at regular intervals.

I'm in the market for a replacement, found my oem(?) spring in two separate pieces.......

Have you
 

quantified the effect on fuel economy?

At that pressure with the stock pump spring, how much by pass fuel are you seeing?

The lift pump is a positive displacement pump, it will bypass exactly the same volume of fuel that it did at 15psi, just maintain a higher pressure in the fuel gallery of the IP.

What about for OM606 Turbo engines?

Yes Sir.

The company that manufactures the spring did the testing you describe after calculating the specification.

Still your original spring or any other spring is not to blame after 30 years of hard work :D and several billion cycles ....


Gruß
Volker

Have to say I'm certainly interested then :)

Yes it is a positive displacement pump, BUT, it is the piston return spring that generates the pressure, the cam only moves the piston back, compressing the spring, (actually when the piston goes back, it transfers the fuel on the outboard side of the piston to the inboard side of the piston), and the spring tries to move the piston back (drawing in fuel on the outboard side, and pushes against the fuel creating pressure on the inboard side. If the fuel is able to flow freely then no pressure. If you dead head the pump output line then the fuel pressure will be what ever the pump spring tension is.

As I recall, the pump on a NA will generate just above 15 psi dead headed, and a dead headed turbo pump will generate just over 30psi. I installed a stronger pump spring in my pumps and am running 30/36 psi with a good amount of bypass fuel.

You are right, the overflow volume decreases a little bit, but not that much.
Tested with my old untouched presupply pump with 130k miles on it I had like 10%less overflow volume.

Or to give an example. This August I had some fuel with ~50% gasoline in my car.
After I went shopping (I drove the car for 1hour before) the car would not start when I wanted to leave after 20min shopping because of vapor bubbles in the fuel system.

1. cranking 2 seconds long - nothing happened
2. cranking - after 5 seconds I already heard a few cylinders reporting for duty and stopped
I did wait 5 seconds
3. cranking - after 5 more seconds the engine ran, not nice, but it ran.
And after hitting the gas once the idle was normal.

What I want to illustrate with the example, the overflow volume is still quite sufficient. Even with the wrong fuel. :D

Be careful with stronger springs. Too strong springs in the presupply pump can cause bad engine behaviour.

Diesel fuel can´t be compressed and so it does not store any pressure. The spring in the presupply pump can store the pressure so to say.
If the spring in the presupply pump is too strong the pump stroke is finished earlier through the bigger spring force, but the time until the pump-cam loads the spring again is too long then. In that case the oscillating pressure can cause uneven fuel loading of the elements.
I don´t say it will, but it can.

Gruß
Volker

I guess I will try streching my springs and see,what happens

I went to adjust mine,found no spring,now it won't start.

Performance Overflow Valve
 

What car? Engine?


Sent from an abacus

w126 1983 300sd>cracked injector lines,and fuel weeped out of them.

If My primer pump worked I could bleed all air out.But Its been no good for 4 years.Guess I'll put my electric pump on it to prime it.

One issue I found after installing a stronger pump spring was that the fuel pressure was erratic because the pump could not fill fast enough. i opened up the check valve passage ways which helped a little, but I found that installing a large prefilter vertically so it had an air pocket in it solved the problem. The air in the filter would act as an elastic of sorts, allowing the fuel pump to draw in a charge quickly and then the lower pressure in the filter would draw fuel in slower, like a capacitor does for an electrical circuit.

When I put the engine in the 201 chassis, I used the electric fuel pump to supply the lift pump. I made a pressure regulator to control the pre lift pump pressure, that really made a difference on the top end fuel supply. The stronger pump spring makes the lift pump really want to pump a lot of fuel so I am able to maintain a high pressure with more return flow that OEM. I can see the pressure pulses being at a higher frequency if the return flow was restricted, (not allowing the piston to follow the cam and bouncing off the top of the lobe). I am running a higher volume bypass as well and my thinking is in order to have increased volume, the piston must be following the cam profile closer on the return side, so it could then be argued that the pump frequency should be lower that OEM.. All theory of course..

My goal was to increase fuel supply and pressure, pressure frequencies were not a consideration really, but worth keeping in mind should any strange performance be experienced..

what happens if spring and ball is missing?

Nothing, or almost nothing. The engine won´t start or if it starts it will have no power.
I think it would make sense for you to buy a new overflow valve and a new hand-primerpump :D

Gruß
Volker

I will have to wait for tax refund time

If you have any left and it will fit the M pump, I'll take one. Circumstances require me to remove the IP again so I'll install your valve while I'm at it. Do they come with new crush washers?

I have 2 springs left. I should have another 10 after the New Year sometime. I "have" a box of OFVs but cannot locate them. My overall marketing strategy needs to be tweaked because OFV (the first 10 to 15) was supposed to be no biggie. I figured I could replace those sold through trips to the yards, but I have not been able to hit the yards like I used to (stupid back), plus I did not think I would be dumb enough to misplace the ones I had.

So, I am now offering the following"

$40 shipped BUT $5 refund if you send back your old OFV (assuming it's rebuildable.). I sort of feel bad delaying folks ... especially since my garage is a little disorganized. No aluminum washers. I think they are around .35 cents a pop. The refund has to be within 45 days of original purchase for PayPal to permit refunds OR I have to catergorize the transaction as a dispute. I prefer to avoid that.

PM if interested.

And yes, M pump is fine. I have a "M" pump on my OM617.912 and it has one of these little gems.

I thought both springs were on the fuel filter holder.I checked both,but no springs.I was careful in case a spring shot out.

Take a peek at posts #1 and #7 ... it shows what the OFV looks like and it's general location. Springs on a fuel filter ????

yes I mistook one bolt.I will charge battery today and see if I can crank her up.I will also jump her with my w140

I would need the entire assembly I believe, since the spring is held in place by a permanent cap. I may be wrong but I'd swear there is a banjo bolt with a screw on cap and one like I have that has a permanent staked on cap.

I've never paid super close attention to it though.

There are actually two (2) types: one is rebuildable and the other has an end which appears to be staked in the corners, so you are correct. You most likely have the one which is staked in the corners.

Just a little more positive feedback.

I took the scenic route home today with one particular hill in mind. In the past I had to downshift to 4th to maintain 60mph going up that hill, today I was able to maintain 60mph in 5th gear. Only difference? Greazzer's spring.

First batch of 10 sold and all thumbs up.

Second batch of 10 is now received and for sale. (one is committed for my #315 injector sale).

Thanks in advance !

PM if interested.