My tow pig/DD build thread. F350/Cummins 6.7/twins/6R140

[me2]

Unless you just must have a turbo brake I'd ditch the whole VGT turbo all together. We have done a few 6.7 turbo swaps and those things spool up a 66 like nothing. Zero lag at all, from there you could just add a inline or downpipe exhaust brake and it would probably make fitment easier on you.

I absolutely need an exhaust brake. My trailer weighs 14K and its pretty aerodynamic. At least it was without the kayaks and other junk on the roof. Its a bullet going down 7% grades, though my old truck held it pretty well without an exhaust brake. It has hydraulic disks as well, but I want to save them for emergency stops and not use them to keep things under control.

A new turbo and separate exhaust brake would cost $$$$ and I'm on a budget. I'd like to make the HE351VE work and spend that money on other goodies. We'll see if I can going forward.

So right now I'm committed to sticking with the HE351VE, just to see what it will and won't do, especially in a twins configuration. Call me &*^%^$, but I want to try it.

 

[SEABEE08FX4]

No worries, just a suggestion. Try to put it somewhere you can access it easily, the VGT vanes on those stick worse than the 6.0 turbos.

 

[Project20v]

Please tell me how to do that !

I forgot to post above that the flex plate balance is still one of the things I am trying to figure out.

The Ford flex plate is keyed to the Ford crankshaft and it has big balance weights hanging on it. People tell me the 6.7 is probably externally balanced by the flexplate.

Dodge/Cummins flex plates are NOT keyed to the crank but do have balance holes drilled in them. What is up with that ? Are they just balanced unto themselves or is something else going on ?

I spoke with an engine builder this morning that told me a) they could balance the flex plate by itself and b) it should really be done together with the crank, rods and pistons ! But the same guy told me that I should replace my 6.7 crankshaft with a 5.9 crankshaft because the 5.9 cranks are stronger. He didn't realize that the 6.7 has a longer stroke. So I don't know what to believe.

One more thing. I'll be making up 2 flex plate/adapter assemblies and carrying one along on the truck at all times so that if I break one on a long trip, I have a spare ready to swap in to get me home. Nothing worse than having a custom made part fail and not having a backup available. FYI, a Ford 6.7 flex plate is about $80 IIRC.

One more little tidbit. A little birdie (not Mark K) told me that it would not be possible to weld the Ford flex plate without it cracking down the road, more so than a "normal" flex plate would, due to the heat treatment and metalurgy it has. Whereas some other flex plates can be welded, the 6R140 flex plate should not be.

I know that the starter ring gear is welded to the 6R140 FP as are the balance weights. That is different from welding in a new center, for example.

I've got a ton of other things to blather about from stuff I learned recently, but I want to focus on my swap right now.

The flexplate is balanced to itself. No need to balance it to the rotating assy. unless you have an externally balanced engine.

If you think about it, do you tear the motor down an re-balance when you turn a flywheel, or replace a pressure plate, clutch plate or torque converter?

 

[Hotrodtractor]

Please tell me how to do that !

I forgot to post above that the flex plate balance is still one of the things I am trying to figure out.

The Ford flex plate is keyed to the Ford crankshaft and it has big balance weights hanging on it. People tell me the 6.7 is probably externally balanced by the flexplate.

Dodge/Cummins flex plates are NOT keyed to the crank but do have balance holes drilled in them. What is up with that ? Are they just balanced unto themselves or is something else going on ?

I spoke with an engine builder this morning that told me a) they could balance the flex plate by itself and b) it should really be done together with the crank, rods and pistons ! But the same guy told me that I should replace my 6.7 crankshaft with a 5.9 crankshaft because the 5.9 cranks are stronger. He didn't realize that the 6.7 has a longer stroke. So I don't know what to believe.

One more thing. I'll be making up 2 flex plate/adapter assemblies and carrying one along on the truck at all times so that if I break one on a long trip, I have a spare ready to swap in to get me home. Nothing worse than having a custom made part fail and not having a backup available. FYI, a Ford 6.7 flex plate is about $80 IIRC.

One more little tidbit. A little birdie (not Mark K) told me that it would not be possible to weld the Ford flex plate without it cracking down the road, more so than a "normal" flex plate would, due to the heat treatment and metalurgy it has. Whereas some other flex plates can be welded, the 6R140 flex plate should not be.

I know that the starter ring gear is welded to the 6R140 FP as are the balance weights. That is different from welding in a new center, for example.

I've got a ton of other things to blather about from stuff I learned recently, but I want to focus on my swap right now.

The flexplates are not neutrally balanced as you have seen with the additional weight or extra balancing holes - I can't speak with 100% authority for this combo since I haven't been around either flexplate or around either motor to this extent. Depending on the amount of "off balance" the Cummins flexplate is - a good engine shop can spin the flexplate and determine how far off balance it is and then be able to make your new Ford flexplate that you have already modified to bolt to the Cummins match this same amount of off balance. The Cummins flexplate should be oriented to some feature on the crank somehow - unless it is truly neutrally balanced. If it is neutrally balanced - that makes your life easier. The key is a good balance shop - or some real creative home tinkering.....

The flexplate is balanced to itself. No need to balance it to the rotating assy. unless you have an externally balanced engine.

If you think about it, do you tear the motor down an re-balance when you turn a flywheel, or replace a pressure plate, clutch plate or torque converter?

When you turn a flywheel most of the time the amount of material used is consistent enough that it doesn't matter - when you do a pressure plate, clutch plate, or a TC they are usually neutrally balanced. If you go swapping a flywheel onto a different engine than it was intended for - you better make sure that flywheel balance matches the flywheel balance of the correct for that engine flywheel.

FWIW - if you buy an aftermarket multidisk clutch - it has a match balanced flywheel to factory specs when needed - and then the whole assembly is is balanced and usually paint marked for orientation for installation.....

 

[me2]

The flexplates are not neutrally balanced as you have seen with the additional weight or extra balancing holes

How can the Cummins flexplate be balanced to be un neutral if it isn't timed to the crank or to the torque converter ?

a good engine shop can spin the flexplate and determine how far off balance it is and then be able to make your new Ford flexplate that you have already modified to bolt to the Cummins match this same amount of off balance.

I'll have them check into this.

The Cummins flexplate should be oriented to some feature on the crank somehow - unless it is truly neutrally balanced. If it is neutrally balanced - that makes your life easier.

I can find nothing that times the flexplate or a flywheel to the crank on a 5.9 or 6.7. Am I missing something ?

FWIW - if you buy an aftermarket multidisk clutch - it has a match balanced flywheel to factory specs when needed - and then the whole assembly is is balanced and usually paint marked for orientation for installation.....

This is news to me. I priced a dual disk clutch from both Valair and Southbend, with me providing my own single mass flywheel and nobody mentioned timing the clutch or rebalancing the flywheel.

 

[Hotrodtractor]

How can the Cummins flexplate be balanced to be un neutral if it isn't timed to the crank or to the torque converter ?

I'll have them check into this.

I can find nothing that times the flexplate or a flywheel to the crank on a 5.9 or 6.7. Am I missing something ?



This is news to me. I priced a dual disk clutch from both Valair and Southbend, with me providing my own single mass flywheel and nobody mentioned timing the clutch or rebalancing the flywheel.

Throw the Cummins flexplate on the balance machine and you will know if it is neutrally balanced. I agree with you if you have no locating features - but I guarantee that you need to make the Ford flexplate match balance to it especially since it has that heavy counterweight.

You have never actually looked at a Valair or a Southbend dual disc clutch apparently - if you had you would have seen that the flywheel is a one piece machining with the "tabs" for the floater plate being integrated into the flywheel. Sure you could build a Crower style mutli disc clutch using stand offs but neither of the companies that you mentioned do that for a dual disc.

 

[me2]

Throw the Cummins flexplate on the balance machine and you will know if it is neutrally balanced. I agree with you if you have no locating features - but I guarantee that you need to make the Ford flexplate match balance to it especially since it has that heavy counterweight.

I'll be cutting off the counterweights on the Ford flex plate.

Unless I find out otherwise, I'll be balancing my flex plate to be neutral.

You have never actually looked at a Valair or a Southbend dual disc clutch apparently - if you had you would have seen that the flywheel is a one piece machining with the "tabs" for the floater plate being integrated into the flywheel.

I assumed that was a plate that bolted onto the existing flyweel. I didn't realize it was part of a separate flywheel. I've never seen one in real life.

The original topic of discussion was

FWIW - if you buy an aftermarket multidisk clutch - it has a match balanced flywheel to factory specs when needed - and then the whole assembly is is balanced and usually paint marked for orientation for installation.....

I'm in Quickserve right now, looking at the mounting system for an Allison 2000 to a Cummins 6.7 used in a 2011 F650. ESN 73385439.

There are no keys on the flexplate or crankshaft or torque converter adapter that I can see and that flexplate assembly (option FW90096) is used on a variety of engines ie ISB3.9s, ISB4.5s, ISB5.9s and ISB6.7s. So either all those engines need the same external balancing or that assembly is balanced neutral. I'm thinking its the later.

So any balancing of a dual disk clutch for a Cummins ISB would be for the clutch components themselves, if that was even required at normal engine operating speeds.

 

[me2]

Remember a few pages ago when I was looking for a different way to mount an oil filler, due to concerns about the height of the stock filler and it interfering with the underside of the hood ?

It turns out that Cummins uses a different (second) oil filler on the 6.7s used in Ford F650s. Its on the driver's side of the engine, near the front.

I have not checked that the F650 block is the same as a Dodge Cummins block, ie that it has a port for this filler on the driver's side. There are a lot of differences between the F650 6.7 and a Dodge Cummins 6.7.

Even if the block didn't support that location, I could probably make use of the tube and the cap as part of a different valve cover setup.

The F650 6.7 has a lot of neat things. A different fuel filter assembly, a direct drive fan mount, a different alternator mounting system, a different turbo cover, a different air intake "horn" and a different exhaust manifold. I was interested in the later, but it probably won't work for what I need it for.

 

[me2]

This is the manifold presently on my engine.

The F650 manifold turbo flange exits between cylinders 3 and 4, pretty much straight out the side.

The DC 6.7 manifold turbo flange exits between cylinders 4 and 5, pretty much straight down.

I'm giving these various combinations some thought in lieu of making my own manifold.

 

[me2]

FYI, the power output on the F650 6.7 was 240 HP at 2300, 520 ftlbs.

Fuel consumption at rated power was 116 mm^3.

BSFC

116 x 2400 x 6 / 2 x 60 = 50.11 liters per hour = 13.23 gallons per hour = 92.67 pounds per hour.

92.67 lbs/hr / 240 HP = 0.386 lbs per HP Hr.

That is a little bit worse than the Dodge Cummins 6.7, but then its rated at 350 HP, not 240HP and higher outputs tend to do better, to a point.

 

[me2]

There is a mistake in the above calculation. Rated engine speed is 2300 RPM, not 2400 RPM.

Here is the correct math.

FYI, the power output on the F650 6.7 was 240 HP at 2300, 520 ftlbs.

Fuel consumption at rated power was 116 mm^3.

BSFC

116 x 2300 x 6 / 2 x 60 = 48 liters per hour = 12.7 gallons per hour = 88.8 pounds per hour.

88.8 lbs/hr / 240 HP = 0.370 lbs per HP Hr.

That is a little bit BETTER than the Dodge Cummins 6.7, but then its rated at 350 HP, not 240HP and higher outputs tend to do better, to a point.

 

[Mark Kovalsky]

Dodge/Cummins flex plates are NOT keyed to the crank but do have balance holes drilled in them. What is up with that ? Are they just balanced unto themselves or is something else going on ?

Yes, the Cummns flex plate is just balanced unto itself. Since it is not keyed to the crankshaft this is the ONLY possibility.

 

[me2]

I got interrupted the last few days by other things.

I'm double checking the drawings for the flex plate adapter and transmission adapter plate and sending them in today to get parts made.

I decided I didn't like my SS square exhaust manifold design, so I redesigned it in mild steel and ordered a bunch of butt weld pipe fittings.

I've got another problem on my hands. Last weekend I put 1200 miles on the truck, about 500 of them towing our 5er. My lower back was extremely sore when I got back home on Tuesday but its getting better as the days go by.

I've thus started doing some of the background work on the rear suspension build and I'm also looking into building an air ride 5th wheel hitch.

I need to pull the trailer about 800 miles in July and about 2500 miles in August. If it rides as rough as it did this past weekend, I'm in big trouble. Having said that, I am none too happy with the way the 6.4 performed pulling our 5er on the flats (7.8 MPG @ 60MPH) and the August trip involves lots of mountains.

 

[oildigger]

I was browsing and found this on the De-stroked website. A fully custom ECM.

http://www.destroked.com/zeus.php

 

[Hotrodtractor]

I was browsing and found this on the De-stroked website. A fully custom ECM.

http://www.destroked.com/zeus.php

Yup. There's a few guys running that around the country. Real nice piece of hardware.

 

[me2]

I was browsing and found this on the De-stroked website. A fully custom ECM.

http://www.destroked.com/zeus.php

How exactly does this fit into the scheme of my swap ?

As far as I can tell, the Cummins ECM with EFI Live does everything I need it to do.

CAN Bus is the backbone of my plan to interface the 6.7, the truck and the 6R140 and the Zeus controller does not support CAN Bus.

If I wasn't using CANBus, it would be a wiring nightmare to move all the data around.

????

 

[Buffalo444]

subbed. and I only read the first page. will check out the rest later. BA build man!

 

[me2]

the Zeus controller does not support CAN Bus.

I appear to be mistaken, the Zeus controller does support CAN.

I still don't see how it offers my swap anything that the Cummins ECM doesn't and thus I will not be considering it.

 

[bad12jr]

The zues was a great option until efi got off the ground. The circumstances now I'd go with the cummins pcm if I was going to swap into anything due to efi.

 

[me2]

I am going to be distracted for the next few days with work stuff. I'll work on things as time allows.