Cummins 4BT & Diesel Conversions Forums banner

1 - 16 of 16 Posts

·
Registered
Joined
·
232 Posts
Discussion Starter #1
Please don't flame this with "WHY?" type responses. You're adding nothing useful to the threads. The why here is obvious, a fully mechanical Duramax option. Yes, I understand top end power will be less than that capable of the CR system. IMO 99% of people don't need the power levels it can make stock, let alone hopped up.

With that cleared up, does anyone know if this has been done to create an all-mechanical 6.6? It seems the DB2 and the CP3 pumps have similar (same?) mounting. Injectors would have to be figured out (DI/IDI/pop psi etc). Fuel lines would be pretty straight-forward.
 

·
Registered
Joined
·
17 Posts
With that cleared up, does anyone know if this has been done to create an all-mechanical 6.6? It seems the DB2 and the CP3 pumps have similar (same?) mounting. Injectors would have to be figured out (DI/IDI/pop psi etc). Fuel lines would be pretty straight-forward.
I do not know if it has been done but I know a little bit about those pumps because I am a fan of the Olds Diesels and they like the 6.2L used the DB2. My understanding is that pump can push around 2000psi so if you could get a poppet or pencil injector that would fit the existing threads in the block then you could run custom injector lines. You would need a vacuum source since cold-start advance and idle speed advance is done by vacuum.

If you would permit me to make a suggestion, it might be better with a DB4. Yes, I know that isn't a all-mechanical pump but the electronic controls might be easier to build a controller for using a Adrenio or other microcontroller. If you choose to use either pump then you might look for a set of heads that are damaged but not cracked because it might make sense to tap the injector holes for older DB2 style injectors. Obviously, not something that you wnat to do to a perfect set of heads but something that you might do to a set that would never be used again. Since you can't put the same stress on them that the CR injectors do because of the pressure difference, a damaged set of heads might work well for you.

Just something to think about.
 

·
Super Moderator
Joined
·
8,680 Posts
I'm sure in the last 10 years I saw a picture of a pulling tractor running a fully mechanical duramax. I do not however have any useful information to help you find it.
 

·
Registered
Joined
·
160 Posts
I suspect an 8 cylinder P7100 is a much better choice on a mechanical d-max plus it can be tuned way beyond what any Bull Moose type DB-2 or DB-4 can do.
 

·
Registered
Joined
·
232 Posts
Discussion Starter #5
Thanks for the responses guys.

Good note on the vacuum tssmith2002.

The puller Duramax is a PPump, but that will require extensive modification to even mount it.

The reason for the inquiry is two-fold.
1) The 6.2/6.5 supply won't last forever.
2) They are already getting annoyingly expensive up here at first glance

So I looked at the Duramax and saw the mounting flange and key looks identical to the DB2.

I have no interest in power beyond what the DB2 pump can dish out (I know it can make some very decent power IMO). I'm not in pulling competitions, I'm just eyeing up options for a truck build. The goal is SBCish fitment and access to a newer engine design running a simple mechanical fuel system.
 

·
Registered
Joined
·
160 Posts
Companies into newer technologies have a vested interest in reducing the availability of the DB & DS series injection pumps. One company has already bought the rights to the DS series and has no plans to make it or parts available to the consumer.

Suffice to say I suspect your quest will go I another direction.
 

·
Registered
Joined
·
26 Posts
Once up on a time perkins and international harvestor made V8 engines with a high pressure fuel system (ie injection pump and nozzles).
 

·
Registered
Joined
·
232 Posts
Discussion Starter #8
I'm actually a little less worried about the pumps than I am the engines. Perhaps that worry is mis-placed.

Either way, it seems like undiscovered territory as of yet. I know many are smitten with CR systems just like many are smitten with TPI-EFI (somewhat the same thing if you think about it). I also think most people don't plan on owning a vehicle north of 100k miles. I generally own vehicles well beyond that, not even acquiring them until decently after that in fact. In light of this, I have no love of either of the failure prone systems. The first of the CRs are getting up there in age where we will start to see the effects of having a mountain of single-points-of-failure. If I'm going to build a truck for long term ownership, it won't have a CR system, at least not for long.
 

·
Super Moderator
Joined
·
8,680 Posts
I'm actually a little less worried about the pumps than I am the engines. Perhaps that worry is mis-placed.

Either way, it seems like undiscovered territory as of yet. I know many are smitten with CR systems just like many are smitten with TPI-EFI (somewhat the same thing if you think about it). I also think most people don't plan on owning a vehicle north of 100k miles. I generally own vehicles well beyond that, not even acquiring them until decently after that in fact. In light of this, I have no love of either of the failure prone systems. The first of the CRs are getting up there in age where we will start to see the effects of having a mountain of single-points-of-failure. If I'm going to build a truck for long term ownership, it won't have a CR system, at least not for long.
Commonrail systems for all their complexity are a chain of easily replaced components. High pressure pump, injectors, controller and sensors.

Perhaps your time and energy are better spent finding the most reliable CR system and storing spare parts for 20 years down the track? Commonrail engines have been in production since about the mid 90's and in widespread usage since the early 00's.
 

·
Registered
Joined
·
232 Posts
Discussion Starter #10
Commonrail systems for all their complexity are a chain of easily replaced components. High pressure pump, injectors, controller and sensors.
I'm actually quite good at troubleshooting these type systems. The fact that I do understand how they work, and what owning and fixing them 30 years later means, leads me to WHY I want to remove it, not retain it. But here in lies the rub. Many of these components are replaceable, yes, assuming you can buy them in 30 years. Not only that, the "diesel tax" on this stuff in the US means these parts are ~4x more expensive than the gasoline EFI equivalent due to sales volume being far far less (assuming they do not overlap - and some do). These systems are far too fragile to last the test of time, and several of the components are ripe for planned obsolescence. That isn't something I wanna mess with. I'd much rather keep a set of pop injectors and a spare pump on the shelf. Not only that, the cost of the mechanical parts are a fraction of the CR stuff (today, I'm sure it will go up).

If the mechanical pump swap on the Duramax isn't overly feasible, I'll just go in a different direction, engine-wise. I was mostly wondering if this had been done already. I'm rather surprised it hasn't.
 

·
Super Moderator
Joined
·
8,680 Posts
I'm actually quite good at troubleshooting these type systems. The fact that I do understand how they work, and what owning and fixing them 30 years later means, leads me to WHY I want to remove it, not retain it. But here in lies the rub. Many of these components are replaceable, yes, assuming you can buy them in 30 years. Not only that, the "diesel tax" on this stuff in the US means these parts are ~4x more expensive than the gasoline EFI equivalent due to sales volume being far far less (assuming they do not overlap - and some do). These systems are far too fragile to last the test of time, and several of the components are ripe for planned obsolescence. That isn't something I wanna mess with. I'd much rather keep a set of pop injectors and a spare pump on the shelf. Not only that, the cost of the mechanical parts are a fraction of the CR stuff (today, I'm sure it will go up).

If the mechanical pump swap on the Duramax isn't overly feasible, I'll just go in a different direction, engine-wise. I was mostly wondering if this had been done already. I'm rather surprised it hasn't.
Diesel CR parts are more expensive than petrol EFI due to the pressures involved and engineering/manufacturing required being far more complex. Same deal with mechanical diesel injectors vs carburettors.
 

·
Registered
Joined
·
232 Posts
Discussion Starter #12
Diesel CR parts are more expensive than petrol EFI due to the pressures involved and engineering/manufacturing required being far more complex. Same deal with mechanical diesel injectors vs carburettors.
While accurate, those costs are not truly linear, though. The market volume plays a decently large role here - I gather this is not the case elsewhere with very different economics in play (legislation, taxes, fuel prices, etc).

Even the simple economics (US based) involved are not in the CR camp. On a CRD V8, one can easily spend $5k+ on a refresh of CR pump and injectors where the mechanical equivalent is prolly about $1k. If hot rod power, while maintaining good drive-ability, is the not the objective, IMO there is zero reason to pursue a CR system unless you don't own vehicles past 100k miles, and therefore buy new regardless (and you'll get a CR system). My objective is a 500k mile truck over 3 decades. Doing this with CR can EASILY cost $20-25k more than using mechanical diesel injection, which will likely more than double the cost of travelling those miles. In the end, baring some glaring shortcoming, simplicity be-gets durability and when it's coupled with efficiency be-gets low TCO. That is my build goal.

CRD (and gasoline EFI really..) is awesome for it's flexibility of being pretty good at two things at once (high power and decent efficiency - when emission gear is removed, all the related gear are working perfectly, and it's properly tuned). Again, I don't care about the high power potential. This basically means it's worse at just about everything I care about, and massively more expensive to own while being worse at everything, hence this thread.
 

·
Super Moderator
Joined
·
8,680 Posts
While accurate, those costs are not truly linear, though. The market volume plays a decently large role here - I gather this is not the case elsewhere with very different economics in play (legislation, taxes, fuel prices, etc).

Even the simple economics (US based) involved are not in the CR camp. On a CRD V8, one can easily spend $5k+ on a refresh of CR pump and injectors where the mechanical equivalent is prolly about $1k. If hot rod power, while maintaining good drive-ability, is the not the objective, IMO there is zero reason to pursue a CR system unless you don't own vehicles past 100k miles, and therefore buy new regardless (and you'll get a CR system). My objective is a 500k mile truck over 3 decades. Doing this with CR can EASILY cost $20-25k more than using mechanical diesel injection, which will likely more than double the cost of travelling those miles. In the end, baring some glaring shortcoming, simplicity be-gets durability and when it's coupled with efficiency be-gets low TCO. That is my build goal.

CRD (and gasoline EFI really..) is awesome for it's flexibility of being pretty good at two things at once (high power and decent efficiency - when emission gear is removed, all the related gear are working perfectly, and it's properly tuned). Again, I don't care about the high power potential. This basically means it's worse at just about everything I care about, and massively more expensive to own while being worse at everything, hence this thread.
You know they are running commonrail in million mile overhaul trucks and industrial engines right? The injection systems (provided fuel is kept clean) can outlive the engines.

A mine that was down the road from me had a 450,000km Toyota hilux (commonrail 1KD-FTV). I only saw it parked up because someone broke a door and window.
A mate of mine has a Ford (peugeot use the same engine) 1.6 commonrail diesel with similar mileage on it. He hasn't had any fuel system issues. But he has had leaking seals around the injectors.
 

·
Registered
Joined
·
232 Posts
Discussion Starter #14 (Edited)
You know they are running commonrail in million mile overhaul trucks and industrial engines right? The injection systems (provided fuel is kept clean) can outlive the engines.

A mine that was down the road from me had a 450,000km Toyota hilux (commonrail 1KD-FTV). I only saw it parked up because someone broke a door and window.
A mate of mine has a Ford (peugeot use the same engine) 1.6 commonrail diesel with similar mileage on it. He hasn't had any fuel system issues. But he has had leaking seals around the injectors.
I do know this. My step-father has been in trucking (local and OTR) for ~40 years in the north central US - where I still live. US CRDs are not known for those miles between fuel system services/rebuilds (I'm sure someone will say they know a guy who knows a guy), even with serious filtration systems put in. Could be fuel qualities, could be harsher temperatures, could be many things, but my related experience is that the CRDs cost a ton more to run and several times more to service the fuel system.

The engine internals are rarely ever the issue, hence the thread (once the emissions lunacy is removed). There are million mile Cummins CRDs in the States and Canada, but they very likely have had the fuel system serviced several times effectively murdering the TCO. Also this does not take into account how poorly complex electronics age in this region (apparently not the case by you). If you do not account for the durability of every electric connection/pin/ground, you're missing the point of this little mental exercise. We salt roads here and get significant snowfall and extreme temperatures on both ends. Electronics hate all the above. This leads to higher service cycles, more downtime, costs, rinse repeat - and for WHAT gain (THIS is an important question)? None that I find of any remote value.

I'm not saying CRDs are terrible for everyone. I'm sure some people love em, as you apparently do. I'm saying they are horrible for my use case and even worse for my project. Literally better at nothing I find of value.
 

·
Super Moderator
Joined
·
8,680 Posts
I do know this. My step-father has been in trucking (local and OTR) for ~40 years in the north central US - where I still live. US CRDs are not known for those miles between fuel system services/rebuilds (I'm sure someone will say they know a guy who knows a guy), even with serious filtration systems put in. Could be fuel qualities, could be harsher temperatures, could be many things, but my related experience is that the CRDs cost a ton more to run and several times more to service the fuel system.

The engine internals are rarely ever the issue, hence the thread (once the emissions lunacy is removed). There are million mile Cummins CRDs in the States and Canada, but they very likely have had the fuel system serviced several times effectively murdering the TCO. Also this does not take into account how poorly complex electronics age in this region (apparently not the case by you). If you do not account for the durability of every electric connection/pin/ground, you're missing the point of this little mental exercise. We salt roads here and get significant snowfall and extreme temperatures on both ends. Electronics hate all the above. This leads to higher service cycles, more downtime, costs, rinse repeat - and for WHAT gain (THIS is an important question)? None that I find of any remote value.

I'm not saying CRDs are terrible for everyone. I'm sure some people love em, as you apparently do. I'm saying they are horrible for my use case and even worse for my project. Literally better at nothing I find of value.
My climate is great for corrosion. Which is how we can wear out engines and the vehicle is still good. The mate with the 1.6 CRD was in the UK where it's wet salt all winter and just warm enough to keep rusting. Not a fun car to work on but the electronics have been fine for him.

With that sort of corrosive climate. How are you going to keep a vehicle body and chassis going for the 500,000 miles plus that you're concerned about? Seems to me all your sheetmetal would be doomed at least once and the engine electrics would be the last concern.

The economics for trucking in my area are quite different too. Fuel injection parts would be below brakes and tires for lifetime costs, possibly even below oil and filter changes. The trucking company near me has been in the news lately with a few *accidents*. They are now overhauling brakes on their rigs every 2 weeks. These trucks run several drivers in rotating shifts doing linehaul. Around 1000 miles every day.
 

·
Registered
Joined
·
232 Posts
Discussion Starter #16 (Edited)
My climate is great for corrosion. Which is how we can wear out engines and the vehicle is still good. The mate with the 1.6 CRD was in the UK where it's wet salt all winter and just warm enough to keep rusting. Not a fun car to work on but the electronics have been fine for him.

With that sort of corrosive climate. How are you going to keep a vehicle body and chassis going for the 500,000 miles plus that you're concerned about? Seems to me all your sheetmetal would be doomed at least once and the engine electrics would be the last concern.

The economics for trucking in my area are quite different too. Fuel injection parts would be below brakes and tires for lifetime costs, possibly even below oil and filter changes. The trucking company near me has been in the news lately with a few *accidents*. They are now overhauling brakes on their rigs every 2 weeks. These trucks run several drivers in rotating shifts doing linehaul. Around 1000 miles every day.
No mountains of note here and OTR guys have long stretches of open road, so while brakes are obviously important, they are not as often serviced as mountainous or more urban areas.

Sheet metal is a huge concern for this build (as much or more as the engine choice IMO), which is why I was looking at SBC footprints first. A more standard high volume engine footprint will allow for more flexibility in the chassis choices, more replacement panel options, more high volume rust free trucks from southern regions, and more non-metal body panels options for known bad spots. I'm not a supreme stickler of every little rust spot, but for a 30 year vehicle here, you can pretty well book a full body replacement (even though I plan on coating the entire rig in some type of bedliner) during the time frame, and you may be about due again towards the end.

If the vehicle sees winter driving around here, you can easily start to get crusty effects on electronics in about 15 years without seeing nearly as harsh a treatment as my vehicle will see (I live in a very harsh place far far from any city - 4 people/sq.mi). In those 15 years, you will likely have gone through, or are on borrowed time for, at least one cycle of sensors and their downtime effects obviously vary, as you likely well know. Some poorly designed newer vehicles I've seen as short as 5 years before corrosion degrades signals. Electronics health are more about age and environment than miles IMO. Winter is pretty harsh on vehicles here, and not even just the salt and whatnot. Mice/pests are no friend of electronics either. You're lucky if they simply chew through it. They rarely do. More often they take the coating/protection and cause degraded, but not dead, signals, which are the worse case scenario for troubleshooting/service.
 
1 - 16 of 16 Posts
Top