Differences between 6.2 and 6.5 injectors + references on Bostic

[Sharecropper]

I've been talking with Jeff at Bostic Motors about purchasing one of their GEP 6.5 engines to replace my stock 6.2, and he is wanting to also sell me new Bosch 6.5 injectors to go along with it ($650), as well as a new set of special injector lines to mate my factory 6.2 injection pump to the new 6.5 injectors (another $300). After shipping this equates to almost $1000 of additional costs which I feel may be unnecessary. I had my factory injection pump rebuilt around 1500 miles ago, and installed new Bosch 6.2 injectors at the same time, so my question is, will my new 6.2 injectors work OK with the 6.5 engine? I do not intend to turbo the 6.5, but to run NA, and do not plan on pulling any heavy loads. Seems crazy to spend the extra cash, unless for some reason my 6.2 injectors will not fit. If anyone has any insight on this, please chime in.

And while we are at it, has anybody had any experience with Bostic's engines? They advertise heavily on Ebay and have an excellent feedback score, however when I reviewed the individual feedback posts, they were all regarding sales of injectors and/or block heaters, not engines. I must have scrolled through several hundred feedback posts and not a single one was related to an engine. This alone dampened my enthusiasm for Bostic, which might be premature, but I would still like to know that their engines are built correctly and are dependable. If anyone can provide comments, I will appreciate it.

Thanks.

 

[Drock]

Well I'm in the same boat as you. I have a set of their NEW after market heads on my 6.2 and they have worked very well. at least until my bottom end let go I've bin contacting Jeff via Ebay messages about their Optimizer 6.5. He told me I'd have to recalibrate my 6.2 injection pump to run with the 6.5, and from what I've read on the interwebs that's true. Apparently simply turning up the fuel on a 6.2 pump isn't enough, Power will be down. As for the 6.2 vs 6.5 injectors, I'm not sure if they would make any difference once you had a 6.5 injection pump? As for the injection lines they will work with the 6.2 injectors but will sit a little higher over the valve covers then before. But from what I understand the 6.5 injectors are a little taller so at that point you might need new lines?

 

[ken]

If you only have 1500 miles on your IP and injectors they will work just fine. The 6.5 injectors have a higher pop pressure. They may provide you with a very small increase in power. Although you would most likely not notice. If I was in your shoes I would reuse your injectors.

 

[Kaiser67M715]

There is no difference between 6.2 and 6.5 NA pop pressures. Pop for NA motors is 126 bar (multiply by 14.7 for psi) 145 bar for turbo motors.

There are several styles of 6.2 injectors, tall with coarse thread, tall with fine thread, and short with fine thread. 6.5 is short with fine thread. You should have either the tall or short with fine thread. Your injector lines and injectors will work fine. If you ever decide to get 6.5 injectors, they will connect fine to your current hard lines, although some minor bending may be needed.

While you could send out your pump to be recalibrated, you likely won't notice much, just turn the fuel up a hair. You would notice it more if you intend to turbo the motor.

Sent from my SM-S920L using Tapatalk

 

[Kaiser67M715]

Oh, and take a run over to dieselplace.com, read reviews there, but not many speak highly of Bostic.

I'm not sure what your budget is and if you only want new, but two places I recommend are leroy diesel, for new, and teds trucks (ebay) for used surplus/takeout engines.

Sent from my SM-S920L using Tapatalk

 

[Sharecropper]

Oh, and take a run over to dieselplace.com, read reviews there, but not many speak highly of Bostic.

I'm not sure what your budget is and if you only want new, but two places I recommend are leroy diesel, for new, and teds trucks (ebay) for used surplus/takeout engines.

Sent from my SM-S920L using Tapatalk

Thanks everyone. And Thanks Kaiser. After snooping around a bit, I feel much more comfortable with Leroy than with Bostic. I plan to reach out to him on Tuesday regarding a new drop-in long block for my M1028.

And to answer your question, I am 67 years old and spending my daughter's inheritance. Yes I want all new stuff and don't really care what it costs. She can deal with it after I am gone.

 

[Iceman3005]

Using 6.2 injectors or 6.5 injectors doesn't matter unless they are coarse thread 6.2 injectors. What matters is the pump, the 6.2 pump has smaller plungers in the injection head, thereby not providing as much fuel to the engine. Even if you turn up the screw its still not going to be enough.

The DB-4911 pump has the larger plungers 12mm I do believe. There are two other pumps that have have larger plungers but they are hard to come by and can be very expensive, one of them is the marine version but to use the marine version requires changing some of the internals from what I understand. Really not worth messing with it.

You could use your current injection pump on the 6.5 and see if you noticed any difference. Also you can use your 6.2 injector lines on the 6.5, you will have to use your 6.2 injectors because the 6.5 injectors are shorter and the injection lines will hit the valve cover.

 

[Sharecropper]

Thanks Iceman. I think I will take the next step and see what happens. I was really wanting to use my open plane intake, rebuilt IP, and new Bosch injectors because all of it is clean and new. If Leroy's 6.5 long block seems fuel starved after I get it all back together I guess I will go to the next step. I plan on calling Leroy tomorrow and discussing it with him. I will re-post afterwards and let everybody know what he said.

 

[Kaiser67M715]

Using 6.2 injectors or 6.5 injectors doesn't matter unless they are coarse thread 6.2 injectors. What matters is the pump, the 6.2 pump has smaller plungers in the injection head, thereby not providing as much fuel to the engine. Even if you turn up the screw its still not going to be enough.

The DB-4911 pump has the larger plungers 12mm I do believe. There are two other pumps that have have larger plungers but they are hard to come by and can be very expensive, one of them is the marine version but to use the marine version requires changing some of the internals from what I understand. Really not worth messing with it.

You could use your current injection pump on the 6.5 and see if you noticed any difference. Also you can use your 6.2 injector lines on the 6.5, you will have to use your 6.2 injectors because the 6.5 injectors are shorter and the injection lines will hit the valve cover.

So a DB2831-4911 pump is a 6.5 turbo pump, calibration is different from an NA pump.

There are three basic mechanical injection 6.2/6.5 pumps, DB2829 and DB2831 and a marine version DB2833. All 6.2 use the .29 pump, which is the plunger size. 6.5 use the .31 plunger, marine is .33.

The last 4 numbers are calibration numbers, but can be usefull to find a pump for a specific application-like turbo or naturally aspirated.

A common 12volt 6.5 NA pump is DB2831-5088. This can be calibrated to 4911 specs if you later want to turbo. I'm can't remember if the cucv used a 24volt topcover or not.

Sent from my SM-S920L using Tapatalk

 

[Sharecropper]

OK as the original poster, I apologize for taking this thread in a slightly different direction. What started out as asking for the diferences between 6.2 and 6.5 injectors, along with a reference on Bostic Motors, has morphed into something much bigger, namely, pumps and now engines. And now, sources for those engines.

I've been back-and-forth with Leroy ( leroydiesel.com ) over the past couple days and here is what I have learned. Yes his first name is Leroy and he is located in Houston TX. I have watched many of his YouTube videos and, surprisingly, it seems he does most of his work in his driveway. He appears to be a 1-man operation. I don't say this in a negative way, because it does appear that he really knows his stuff on diesel engines, which is all that really matters for this thread. I understand that he doesn't "build" the Optimizer or P400 engines, but instead purchases the long blocks from GEP (which stands for General Engine Products, a subsidiary of AM General located in Franklin, Ohio). He resells the long blocks as-is (for a profit, of course), or adds other other parts as required. His website offers a variety of parts for sale, which are also available from a multitude of other internet vendors. His YouTube videos are enjoyable to watch, and he seems to be an honest upstanding person.

He confirmed that the differences between the GEP Optimizer 6.5 and the GEP P400 6.5 long blocks are as follows:
Castings - Optimizer is Dalton, P400 is Navistar
Crankshaft - Optimizer has cast iron, P400 has forged billet steel
Heads - similar casting, but Optimizer valve seats are induction hardened while P400 uses hardened inserts. P400 also has thicker decks w/improved cooling passages
Pistons and Connecting Rods - Optimizer has cast iron, P400 is forged steel

P400 also has a built-in web main bearing girdle which extends downward sort of like an extension of the engine casting. This 1-piece cast iron girdle comletely encircles the bottom end and takes the place of part of the oil pan, thereby requiring the use of a special oil pan (which he also sells) in certain circumstances to clear the front crossmember. I have not yet learned if the special oil pan is necessary in our CUCV trucks, maybe someone with this knowledge can chime in. In summary, the P400 is a beast, and is far and away a much stronger engine than the Optimizer. Both long blocks are a 6-8 week lead time.

On Leroy's website he offers the Optimizer long block for $6,850 and the P400 for $7,999, plus $200 crating and actual LTL freight to the destination. When I saw this I thought it was a lot of money for a long block, but then in an email I got from him today he said the price on the P400 had just went up to $8,400 plus crating and freight. I then thought to myself, Dayum, I must have slipped up and told him about my daughter's inheritance I am spending.

Here is my mindset right now - I am totally committed to obtaining a new P400 long block for my M1028, but it may not come from Leroy. He is requiring full payment up front, preferably via bank wire transfer, before beginning the process. I conveyed to him in an email that I have been in manufacturing and sales for 40 years, and I have been paid only after delivering a finished product to the customer. Leroy wants full payment before he will even order the raw materials. And unlike Amazon or Ebay, I cannot find a feedback score on Leroy anywhere on the internet. I conveyed this to him in an email, and he referred me to his Facebook page. We all know that any post on a Facebook page can be deleted by the administrator, so this sorta tuned me off.

So as of now, I am exploring for alternative sources of the P400 long block. If anybody can provide any guidance, please chime in.

Thanks.

 

[Iceman3005]

https://www.peninsulardiesel.com/ they may have the p400.

That engine sounds sweet with all the upgrades.

Sent from my SM-G928P using Tapatalk

 

[Iceman3005]

https://usengineproduction.com/gm-6...MIur6loJeu2wIVU7jACh0KogN3EAQYAiABEgImJvD_BwE

Sent from my SM-G928P using Tapatalk

 

[Drock]

http://leroydiesel.com/products/p400-6-5-long-block/ Leroy Diesel seems to have it cheaper. Not sure after shipping & core charge? But really at these prices your entering 12 Valve territory

 

[Sharecropper]

Well I did it. I just verbally committed to a P400 from Leroy and will seal the deal in the morning. I will keep everyone posted on developments. Thanks everybody for your advice and comments.

 

[rsh4364]

Congratulations on your choice, please keep us posted. That is my dream motor.

 

[Sharecropper]

OK the dye is cast. I have become comfortable with Leroy and the paperwork is moving. The P400 long block will be assembled at GEP and shipped directly to me here in Kentucky. Lead time is 6-8 weeks. I will photo-document the entire process and add everything to my rebuild thread.

I already have a completely built Level 2 700R4 transmission from Bowtie in California. It's still strapped to the pallet it arrived on in 2016. The engine/transmission combo should be fun to drive. I plan to run it non-turbo with a set of Stan's stainless steel headers and low restrictive muflers.

Thanks again everybody for your comments and advice.

 

[rsh4364]

I have been wanting to hear one of our 6.2/6.5 diesel engines with a set of Stan's for years.

 

[Iceman3005]

Looking at the hp numbers on his site and considering all the re-work they have done to that engine. I bet those numbers are modest.

Sent from my SM-G928P using Tapatalk

 

[rsh4364]

OK the dye is cast. I have become comfortable with Leroy and the paperwork is moving. The P400 long block will be assembled at GEP and shipped directly to me here in Kentucky. Lead time is 6-8 weeks. I will photo-document the entire process and add everything to my rebuild thread.

I already have a completely built Level 2 700R4 transmission from Bowtie in California. It's still strapped to the pallet it arrived on in 2016. The engine/transmission combo should be fun to drive. I plan to run it non-turbo with a set of Stan's stainless steel headers and low restrictive muflers.

Thanks again everybody for your comments and advice.

That motor is built in Franklin,Ohio. Just about 2 hrs straight north of you.

 

[Kisssniper]

Hello gang,

I purchased a set of Stans Headers some time back for my 86 M1008. My combo that I have created is: 37 inch tires, K&N air filter, dual 3' exhaust with series 40 flowmasters. The combination is a daily driver achieving 15 to 18 MPG, entire drive train is stock form. The headers are pricey but there is a noticeable difference on acceleration, the motor seems to run smoother and wide out faster. I currently have 75K on odometer and purchased the truck with 62K.