Builds DieselFJ… BUILD - Cummins ISB170, Eaton 5spd, Tons, SAC, 40’s, Caged (1 Viewer)

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Great to know about the tuning. Have you had any done or is yours stock?

Your weights are quite different from numbers I've got from our 10k shipping scale and digital crane/forklift scale.
I have both (well actually 3) ECM's
one stock
one with +40hp fuel & 3500 rpm (using this one)
one with +100hp and 4k rpm... (but I do not have compounds / airflow req'd for this) but had it programmed "for someday"

not sure what weights are quite different - I was agreeing / stating our shop sale showed about that same within 200lbs .... there's a ton of info on drivetrain weights
"it is what it is"

the biggest difference is the front engine area "package length" and resultant CG

my build could not accommodate a 6cyl cummins ... And the 4bt was not as smooth and a bit vanilla for my taste ( I had done two 4bt conversions prior) so when my son and I wanted to build something the common rail 4cyl is what we chose.

The C2.8 was not really as main stream for our area and did not have the in-use hours/miles IMO but that's a strong choice too... my setup really fits what I wanted:
- Diesel
- minimal "needed" wires to operate engine reliably
- Longevity of the engine / history
- Torque
- somewhat compact (she is a very tall engine - even with oil pan swap options)... but its maybe 8-10inches shorter than the 12v or 5.9/6.7CR
- SAE2 clutch is beefy & eaton is pretty stout

of the top of my head - those were the major thoughts on how I got to a common rail 3.9L cummins

6cyl too big
C2.8 unproven at the time and smaller/less power
 
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I didn't mean to derail your thread with all the weight discussions. Sorry!

I felt I should respond to the statements that a 6BT is just too heavy or required a special fabricated frame to support it. That's all. I completely understand where you're coming from WRT the 6BT not fitting in an FJC- It just doesn't. That is an excellent reason not to use it!

Where my opinion differs is in situations where the length to fit the 6BT is present, they usually work great. Even if the frame rails aren't made from 1/4" wall boxed tubing.

I have some first hand experience with the R2.8. It is not an engine I would choose to swap into anything. If I had to describe the R2.8 in one word it would be Cheesy. They have way too much plastic on and inside them. A bicycle chain runs the overhead camshaft on plastic guides in the rear timing housing. The one I disassembled had several mis-machined areas. There were some subtle, but very real manufacturing details that screamed "cheap Chinese garbage" inside them.

ISB170 is a real good engine. Great to hear there are tuning options for them today. I might have to try one again.
 
I didn't mean to derail your thread with all the weight discussions. Sorry!

I felt I should respond to the statements that a 6BT is just too heavy or required a special fabricated frame to support it. That's all. I completely understand where you're coming from WRT the 6BT not fitting in an FJC- It just doesn't. That is an excellent reason not to use it!

Where my opinion differs is in situations where the length to fit the 6BT is present, they usually work great. Even if the frame rails aren't made from 1/4" wall boxed tubing.

I have some first hand experience with the R2.8. It is not an engine I would choose to swap into anything. If I had to describe the R2.8 in one word it would be Cheesy. They have way too much plastic on and inside them. A bicycle chain runs the overhead camshaft on plastic guides in the rear timing housing. The one I disassembled had several mis-machined areas. There were some subtle, but very real manufacturing details that screamed "cheap Chinese garbage" inside them.

ISB170 is a real good engine. Great to hear there are tuning options for them today. I might have to try one again.

I
HAHA - no worries at all and I always think it's great and appreciated to get real world "use" experience... no issue chatting over weights. But you add good narrative around "6bt being too heavy or too big misconception".... it's my FAVORITE engine and internal balance/smooth/powerful... it's my absolute FAV.
(not sure about this formatting/ indentation)
I am building a 6.7L 2016 block currently with Hamilton Race crank and Carrillo hybrid rods/pistons - shaving almost 42lbs of recipe mass :).... not sure if I will make enough power to justify conversion to P-Pump but I love that simplicity of the all gear timing and almost ZERO sensors.... not sure If I will convert the 6.7L to p-pump or keep as CP3 and compounds .... end game is ultra-quick spool and low/mid torque responsive monster.... it's going my tow-pig (Fummins)... target 650-700hp

I love the 6cyl cummins and you are right to call out that it can be handled in many more applications than peeps think... I just tend to "over-do" the fab work and when an engine bay is clear/open I like to add or reinforce the factory frame rails ... what's 50-100lbs of added steel frame support going to hurt :)
 
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I didn't mean to derail your thread with all the weight discussions. Sorry!

I felt I should respond to the statements that a 6BT is just too heavy or required a special fabricated frame to support it. That's all. I completely understand where you're coming from WRT the 6BT not fitting in an FJC- It just doesn't. That is an excellent reason not to use it!

Where my opinion differs is in situations where the length to fit the 6BT is present, they usually work great. Even if the frame rails aren't made from 1/4" wall boxed tubing.

I have some first hand experience with the R2.8. It is not an engine I would choose to swap into anything. If I had to describe the R2.8 in one word it would be Cheesy. They have way too much plastic on and inside them. A bicycle chain runs the overhead camshaft on plastic guides in the rear timing housing. The one I disassembled had several mis-machined areas. There were some subtle, but very real manufacturing details that screamed "cheap Chinese garbage" inside them.

ISB170 is a real good engine. Great to hear there are tuning options for them today. I might have to try one again.
Also - the C2.8 became stupid expensive... that matters too IMO... the isb170's cold be had reasonably for a while... they seem a little scarcer but still reasonable
 
We have some parallels here- I have a mild 12 valve in my ZF6 crew Superduty. I have zero complaints, but after owning a 2009 Dodge for awhile I miss that tuned 6.7 bottom end power. The 6.7 could squish you back in the seat at 1200 RPM in 6th with a 10K trailer in tow. It was effortless power. I don't miss the Dodge electronics though. Always something failing. I have had more than my share of Cummins ECM failures as well. As anecdotal as that is for the number that are on the road it pushes me towards a mechanical engine. I would prefer a P-pump on the 6.7 provided I can get injectors that run clean with the 6.7 bowls.
 
We have some parallels here- I have a mild 12 valve in my ZF6 crew Superduty. I have zero complaints, but after owning a 2009 Dodge for awhile I miss that tuned 6.7 bottom end power. The 6.7 could squish you back in the seat at 1200 RPM in 6th with a 10K trailer in tow. It was effortless power. I don't miss the Dodge electronics though. Always something failing. I have had more than my share of Cummins ECM failures as well. As anecdotal as that is for the number that are on the road it pushes me towards a mechanical engine. I would prefer a P-pump on the 6.7 provided I can get injectors that run clean with the 6.7 bowls.
singing my language!! yeah, I am very on the fence... as I built the bottom end like it's a sled-puller but don't want that power or smoke... just insane quick spool... and slight concern that I will out ski my ski's (knowledge) of injector, timing, bowl etc as you said... I won't basically a 650hp tuned quick spool tow monster 6.7L p-pump 48v. LOL... guess we will see (I'll up load some engine pics) :)
 
At the risk of hijacking, my own thread… 😝… who can resist Cummins engine pics??

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What cam are you running necessitating those valve reliefs? Compression ratio? That looks like a high RPM build, not so much a grunt DD setup at all?

I've enjoyed the Colt stage 2 grind for DD/towing. I tried the stage 3 Colt and hated it. Lost all the grunt under 1500 and gained nothing until 2500+. Smoked all the time down low. Not good. I've also run 15.5:1 CR on the street and that was another poor choice. Smoked the neighborhood out at every start, but hey, it was an animal from 40-80 PSI lol. There's always a trade off it seems. Regardless of what the folks selling the parts say. I've gone back to the stock camshaft and making the power with careful head port work, good injectors and tuning/turbo for the application.

Maybe I shouldn't say this as I know how things take longer than I expect. I bought a Froude waterbrake turbodiesel dyno cell to test and break in my Cummins engine builds. I'm starting with 12 valves. I'm currently working on the best CNC port/bowl design for the street. All the stuff out there is way over the top for a 5.9 on the street. But a stock head needs a lot of cleanup and has a lot of inconsistency from one cylinder to the next and from one head to the next varies a lot. Especially the new casting heads. They kinda suck.

I've done dozens of Cummins engine builds and found the ones that really put the biggest smile on my face are the ones with the widest powerband. With really nice manners at the bottom, no smoke, but wicked throttle response and mid-top end power. I bought the dyno because I want consistency and the ability to quantify everything is the only way to do that. Plus I hate trying to track and fix leaks in the vehicle and it's a PITA to properly break in rings when you have a un-tuned Allison or other fresh drivetrain parts you are unsure of during the test drive. Also, when you put a Cummins in a 4000 LB early 2wd pickup it's not really possible to load the engine when it accelerates as fast as it revs.
 
Not gotten there yet on the Cam but had built the last 12v with the Hamilton Cams 178/208 "towing" Cam. Really enjoyed that power band... but to answer your question - have not gotten to Cam selection yet and really appreciate any insight.

Definitely built the bottom end for RPM but that was mainly for my enjoyment from time to time to spin up to 4k on the on-ramps etc or rev matched downshifts and engine brrrrrraaaaapppppp braking. But she has no plans of being high Rev for long periods of time.

"Target" is crazy spooling broad power band with LOW EGT and typical towing load is 10k-12K ... but absolute blast to drive (low smoke) when not towing/loaded.... looking at a professionally Ported or worked Head (open to your ideas here too:)

thx.
 
Just found this thread. Looking forward to updates!
 

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