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6.5 Diesel Injector Rebuild

I found the injectors with the made in Italy nozzles and pintles. ebay item. It shows that information in the full description.
www.ebay.com

6.2 6.5 Chevy General Motors Diesel Fuel Injectors | eBay

Find many great new & used options and get the best deals for 6.2 6.5 Chevy General Motors Diesel Fuel Injectors at the best online prices at eBay! Free shipping for many products!
www.ebay.com
 
I did not know there was a "van" application for these injectors nor a difference between the 6.2 and 6.5 with fine thread. I had always thought only non turbo 6.2 (long body coarse thread) and the short body fine thread which I thought was the same injector for both 6.2 and 6.5 van and truck alike. I guess I have more to learn here!
 
dbrannon79 said:
I did not know there was a "van" application for these injectors nor a difference between the 6.2 and 6.5 with fine thread. I had always thought only non turbo 6.2 (long body coarse thread) and the short body fine thread which I thought was the same injector for both 6.2 and 6.5 van and truck alike. I guess I have more to learn here!
Click to expand...
I know the older 6.X diesels had different injectors. IIRC, a short and a long body. I think the later version is the short body.
 
There are a lot of ideas being thrown around here and quite a variation in pressures mentioned. How does someone decide what pressure they should have for their particular application? It sounds like the higher the pressure the better for efficiency and better burn.
 
There in lies the debate.
Use the stock turbo as a floor, and choose if you want to play the game of how high.
How much money are you willing to spend- because at best you mpg improvements from it will maybe break even down the road, not like you will get thousands ahead on one vehicle. Buy the ebay pop tester or diy one. And the hard part now days- shim assortment.
Now buy two sets of injectors. Measure all 16 and get 8 balanced within 25psi of each other, install them and run the engine. The other set set them wt 200 psi higher. If new engine - run them until the engine is well broken in. Say 6,000 miles. In that time you will know the mpg, 0-60 empty, and tow a camp trailer or something that will maintain set weight up your favorite hill.

Then at the mileage, swap the injectors and record the difference. The set you removed, raise 200 over what is in the truck now. Drive it recording same data- 0-60, mpg, tow test. Keep doing this and swap out injectors at each oil change or whatever interval you choose. Some guys do it all day after day until they find the happy place.

It might look something like this:

2000
2200 better
2400 better
2600 drop In results
2500 better than 2400 and 2600
Try 2550 best results so far
Try 2525 and 2575
Whichever is best- now you know which is perfect for your truck.
Obviously set the other injectors set to that level. Keep the specifications
And store the injectors and tester away with a copy of those numbers.

When the injectors has 100,000 miles on them, swap them and rebuild the removed set so they are ready to go the next 100,000 miles.

Option B- buy some from Leroy, install and forget it.
 
SnowDrift said:
What are Leroy's set at?
Click to expand...
I asked Leroy if His injectors are balanced. His reply.
They are brand new Bosch and balanced at the factory.
He didnt mention what pressure they are set at.
$449.93 and no core.
Set of 8 brand new Bosch injectors with crush washers. No core charge.
These already flow more fuel than the IP can output.
Thats typed into here from His we site.
 
Pop pressure is uses to control duration. The injection pumps handles the fuel volume.

If you look at factory pop pressure is was raised for turbo and again for marine applications. This is because pump volume was increased for the turbo and marine 6.5s. With a Db2 you increase fueling by increasing the roller to roller clearance. This allows the roller to move father out and increase the fuel volume in the pumping chambers. But by doing so the roller will contact the camring lobe earlier thus advancing the start of injection and increasing the duration of fuel being injected. Pop pressure is raised to then bring the start of injection and duration back into spec. On some of the big DB2s its not uncommon to see 3k psi of pop pressure. On a dS4 the fueling is controlled a little differently but the same concept applies.

The added atomization from higher pop pressure really doesn't do anything for power in my option. Yes it makes an more complete burn. But The IDI is a 2 part combustion process. Fuel is atomized when it goes through the pressure differential created by the precup. The higher velocity swirl pushes all the fuel to the wall of the prechamber anyway. So the finer mist of fuel really isn't doing anything for the second part of the combustion process that occurs in the swirl bowl of the piston. That the part that matters the most since combustion pressure is needed to push on the piston.
 
Rockabillyrat said:
Pop pressure is uses to control duration. The injection pumps handles the fuel volume.

If you look at factory pop pressure is was raised for turbo and again for marine applications. This is because pump volume was increased for the turbo and marine 6.5s. With a Db2 you increase fueling by increasing the roller to roller clearance. This allows the roller to move father out and increase the fuel volume in the pumping chambers. But by doing so the roller will contact the camring lobe earlier thus advancing the start of injection and increasing the duration of fuel being injected. Pop pressure is raised to then bring the start of injection and duration back into spec. On some of the big DB2s its not uncommon to see 3k psi of pop pressure. On a dS4 the fueling is controlled a little differently but the same concept applies.

The added atomization from higher pop pressure really doesn't do anything for power in my option. Yes it makes an more complete burn. But The IDI is a 2 part combustion process. Fuel is atomized when it goes through the pressure differential created by the precup. The higher velocity swirl pushes all the fuel to the wall of the prechamber anyway. So the finer mist of fuel really isn't doing anything for the second part of the combustion process that occurs in the swirl bowl of the piston. That the part that matters the most since combustion pressure is needed to push on the piston.
Click to expand...
So, if the IP is set up to handle the fuel volume, is more than one pop of the injector for each stroke of the IP possible ? So to speak, a chatter affect of the injector for each inject cycle ?
 
MrMarty51 said:
So, if the IP is set up to handle the fuel volume, is more than one pop of the injector for each stroke of the IP possible ? So to speak, a chatter affect of the injector for each inject cycle ?
Click to expand...

It can only fire one time for each injector per one revolution. There are 8 lobes on the cam ring.

Injectors chatter on a pop tester because the volume and duration of fuel is drastically higher when compared to what the pump is doing. a 100cc pump is based of 1000 revolutions at a particular RPM. So that's only .1cc per single injection event.
 
Rockabillyrat said:
Pop pressure is uses to control duration. The injection pumps handles the fuel volume.

If you look at factory pop pressure is was raised for turbo and again for marine applications. This is because pump volume was increased for the turbo and marine 6.5s. With a Db2 you increase fueling by increasing the roller to roller clearance. This allows the roller to move father out and increase the fuel volume in the pumping chambers. But by doing so the roller will contact the camring lobe earlier thus advancing the start of injection and increasing the duration of fuel being injected. Pop pressure is raised to then bring the start of injection and duration back into spec. On some of the big DB2s its not uncommon to see 3k psi of pop pressure. On a dS4 the fueling is controlled a little differently but the same concept applies.

The added atomization from higher pop pressure really doesn't do anything for power in my option. Yes it makes an more complete burn. But The IDI is a 2 part combustion process. Fuel is atomized when it goes through the pressure differential created by the precup. The higher velocity swirl pushes all the fuel to the wall of the prechamber anyway. So the finer mist of fuel really isn't doing anything for the second part of the combustion process that occurs in the swirl bowl of the piston. That the part that matters the most since combustion pressure is needed to push on the piston.
Click to expand...
By the book- I agree. That is how it is all supposed to work.
The problem I have - is we just played with it out of interest after having to swap turbo injectors into an n/a truck and instantly felt the difference. Then because mpg had been being recorded, we watched expecting to see worse mpg. It didn’t happen- it actually got better. Well, the first tank or so wasn’t- but the driver said because he felt the difference he was playing around more- spinning tire around corners, etc. But when he was used to it after a few hundred miles he started driving normal again.

So we did the same thing on another non turbo pickup- same results.
So then we started playing with it. Quickly the difference of balancing the injectors (we called it equalizing and we did it to 20 psi range because our gauge was every 10 psi) and that proved a no brainer. Honestly I couldn’t tell 20 vs 30, but 40 was noticeable without telling a driver. We would swap them out after being balanced and they would come back stating “something is wrong- it is shaking a little”.

So rather than confuse the narrative I just say 25 psi since that is where most the world seems to agree.

Is it better atomized? Idk. We tried bumping timing both db and ds pumps. Did not get the same effects. Atomized finer is just the best guess because it look that way when testing. Idk if closing the event window to a more compact time is what actually helps-
But if you set up a torch and test spray into the fire- you definitely see a difference in it.

So this is all why I am convinced it is atomizing better helping mpg and power.

Oh yeah, one engineer wasn’t convinced about the mpg, he thought the drivers were sneaking in a little fuel to skew the numbers just so they could have a truck that would finally do a lil burnout. Haha. So we put an engine on the dyno and a measured it. It wasn’t a great amount, but was there.
 
So from what I’m gathering here stock non turbo spec is 1850 , turbo is 2050. And marine is 2350 or so. Since most of ours are turboed. I’m thinking the better all around figure would be to get a happy medium between stock turbo and marine pressure lime 2150-2175?
 
Getting ready to go to the parts store. Get some 1/2” clear hose and 3/8ths and 5/16ths fuel hose in the SAE30R9 capability.
Also going to order in the T feed line fitting to install a gauge at the IP.
Try to get this all accomplished before the 5th of April.
Back surgery date.
 
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