[slow600]

cheapest i see ve pumped motors in my area is 3k and they look rough af and sell in a matter of hours. ive only seen a few p pump models and they were over 5k in similar condition.

 

[marshallnoise]

I think that dude in Ohio, McKinney, he is really driving the prices up for some reason. I don't know how he gets all of those engines, but I guess that is a topic for another thread.

 

[slow600]

I think that dude in Ohio, McKinney, he is really driving the prices up for some reason. I don't know how he gets all of those engines, but I guess that is a topic for another thread.

he has mostly moved on to the r2.8 and making his own adapters, the ones i see are on marketplace or craigslist. he was the go-to for cummins engines for a looong time for sure.

 

[char1355]

The only possible problem I see with all the parts is those 260 bar injectors. VE pumps are set up for 245 bar units which means your timing will be off.

 

[GLTHFJ60]

I was about to post the same thing as Charles. The 260bar injectors are messing up your timing, and probably reducing your overall fueling rate. Swapping out for 245bar injectors would be a significant improvement.

 

[marshallnoise]

I am going to pull an injector today and pop test it and see where it is popping. If these are original (and they might be), then they could have thousands of hours of run time and might not be popping at 260 bar.

I will report the results later. Thanks for the heads up fellers.

 

[marshallnoise]

So I bought a pop tester off Amazon and pulled two of my injectors and they are popping at 3800 to 4000 psi. According to the webz, that's 262-265 bar so no good for my VE pump.

Now, I have a bunch of 9 mm 1st gen injectors laying around. I already pulled one of the 9 mm units apart and it sure looks like the shims are the same diameter. Any objections to pulling the shims out of those and putting them in my 7 mm injectors and seeing if they drop the psi down a bit?

 

[marshallnoise]

Found an interesting link describing what pop pressure differences do for performance. Injector_sizes

"Then there is POP Pressure of the injector or nozzle to deal with. What POP
pressure do you run. Well that all depends on if it is a 12v or a 24v. This does not
apply the Common Rail Cummins as they are EFI not mechanical injectors.

Using the 24v as the example, there is a range on the POP Pressure. This range, ranges from 3800 psi (262 Bar) to as high as 4500 psi (310 Bar). Alot of companies say not go below 260 Bar (3770 psi).

POP Pressure has an effect on timing, smoke and atomization. Plus high POP Pressures have an effect on the fuel being sprayed into the cylinder under high boost pressures. Also, every 10 Bars = 1 degree of timing. 1 Bar = 14.5 psi and 10 Bars = 145 psi. So added 10 Bars of pressure REDUCES the timing by 1 degree and lowering the pressure by 10 Bars ADDS 1 degree of timing. But lower the BAR pop pressure also has an effect on smoke, more smoke.

Rule of thumb is higher POP Pressures help with street driven trucks. Lower smoke, better throttle responce, better drivability and a little lower egt's."

 

[char1355]

Pop pressure needs to be matched to the injection pump system. It's as simple as that. As far as using shims and or springs out of other injectors you can do that. Used springs are often desirable because their tension has settled down and will hold tolerance better. Those little shims come in 30 different thicknesses. You basically add or take away until you get them just right. If you had to buy those shims they are expensive. Like $7 each for those little devils. The problem with taking them out of other injectors is you may not have the right combination and end up having to buy some. That's one reason companies who rebuild injectors charge a lot. And you'll only get those from Bosch or a Cummins dealer. I have the complete list should you need it.

 

[GLTHFJ60]

X2. With a pop tester to verify the pressure, you can swap around shims to get the pop pressure you want/need. Just make sure the injectors pop at about the same pressure.

 

[marshallnoise]

Thanks fellers!

 

[char1355]

One of the secrets of a good running diesel is having the injectors matched as close as possible. That doesn't necessarily mean factory engines match precisely to the bar but a set should be within say a 5 bar range. Although few if any ever do it, would be nice to have 2 matched sets and every so often pull a set for testing and swap in a rebuilt set. Sort of like changing spark plugs in a gas engine only you don't throw away the old ones. Sort of a tune up item. Probably wouldn't do it but maybe every 50,000 miles or more often if engine performance seems a bit off. Changing them isn't major surgery.

 

[marshallnoise]

Thanks for the great info Charlie.

For giggles, I made this.

 

[marshallnoise]

I got the injectors to pop at about 3500 psi which should be about right. It took some doing on one of the injectors with swapping springs, spring pads and shims to get it to pop right, but I did it. I put them in and I would say the engine runs about the same, but the piece of mind that I won't be over-working the pump is good.

I ordered up a couple things from the great jungle website to round out the engine portion of the build. I bought a new liquid filled mechanical gauge to put on the filter housing permanently (plastic line there currently with the gauge hanging by some zipties). I also ordered up a new turbo drain/flange to block thingy. I have a lower water neck on the way. I am fabbing up a mount for the idler pulley (comes out to be abut 1 1/4" thick so far). I need to figure out how to mount my 3G alternator. I don't think it will be too tough. I have a spare alternator to use for mock up.

Then its time for the install.

 

[marshallnoise]

Made the plate up for the idler. I have drilled a couple more holes that I can clock it as needed.
IMG_20210415_152217 by Paul Abbott, on Flickr

And I installed speed parts.
IMG_20210415_153100 by Paul Abbott, on Flickr

The breather works great. Worst case scenario is I have to get a 2nd one if the blow by becomes severe.

Off to research 3G alternator mounting...