A K5 Cummins Conversion: The saga continues...

[MaxPF]

Not at the moment. I need to build transfer case shifters and get new tires.

When is the next CC run?

 

[SuperBuickGuy]

For some reason I thought you were blogging a build that you'd completely finished....

you do excellent work.

 

[CaseyS]

How is the A/C performance with the intercooler out in front? I debated doing this but I think I am going to custom fab an intercooler to go between the condenser and radiator like in a factory setup.

 

[MaxPF]

For some reason I thought you were blogging a build that you'd completely finished....

No build is ever completely finished :wink: I have been daily driving the truck since Christmas, but there's still a bunch of little things and a few bigger things that are still unfinished.

you do excellent work.

Thanks :cheers:

How is the A/C performance with the intercooler out in front? I debated doing this but I think I am going to custom fab an intercooler to go between the condenser and radiator like in a factory setup.

I don't have the AC hooked up yet. I was actually about to pull the trigger on a new Seltec TM-16HD compressor, but I may settle for a somewhat smaller displacement Sanden since they can be mounted with the ports horizontal.Running with the ports horizontal will allow me to run a larger frame alternator, which will be needed for the OBA setup I have in mind...

That said, this Suburban, which belongs to a friend of mine, also has the condenser between the IC and radiator, and it gets plenty cold. His system is running R-12, but he's using an old-style tube and fin condenser AND his burb has rear air! If it cools that well with rear air and an old-school condenser stuffed between the IC and rad, it should work fine for you or I with no rear air and modern parallel flow condensers.

 

[4speedfunk]

Sweet Burb. I'm pulling the SAS trigger on mine this summer.

 

[USMC_TOP]

Hey Max ebay has a np205 case for $125. It's out of a Ford but maybe an adapter from advanced adapters make one to mate it GM

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[MaxPF]

Hey Max ebay has a np205 case for $125. It's out of a Ford but maybe an adapter from advanced adapters make one to mate it GM

Umm, I'm not sure what you're saying/asking

 

[USMC_TOP]

If you can mate a 205 case off a ford to a GM trans. I thought the price of the case was worth looking into

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[MaxPF]

I'm still not understanding where you're going I already have a Chevy 205 in the truck, so why would I need a Ford 205?

 

[USMC_TOP]

lol as an extra being it is cheep.....

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[MaxPF]

Unfortunately, Ford's are drivers drop. And weaker. Chevy cases are pass. drop, and mine is a relatively rare round pattern. If I found an extra round-pattern Chevy 205 locally for a good price I would definitely snatch it up!

Actually, what I really want is a Lomax 205 for $125 :deal:

 

[4speedfunk]

I'll be running a d.s. pumpkin (Ford front axle) on my 99 Burb. The truck came with IFS and the push button Auto-trac 4-mode t-case, which does not function correctly with the solid axle. So I will need to swap to some other t-case. That eBay Ford 205 is the "go-to" case for us GM SAS guys. No adapter needed I think...it's a direct bolt-on to the GM tailshaft.
Max's K5 came from the factory with a solid axle and he's running a p.s. rig (GM front axle) so the Ford t-case is not of much use to him. It's on the wrong side.

But I might be interested?

 

[MaxPF]

So jump on it! If I was running DD stuff I would've probably already bought it. Ford casings seem harder to come by vs GM or Dodge PS 205's.

EDIT: Musta sold. All I found were $250 and up units. They did have bare ford 205 housings for $35 though. If you had a PD 205 as a parts donor you could build a DD 205 on the cheap.

 

[4speedfunk]

I'm undecided on the 205. Might stay with the 241/243 GM unit. I want to get the axle swap figured out first.

 

[MaxPF]

I'm undecided on the 205. Might stay with the 241/243 GM unit. I want to get the axle swap figured out first.

Nothing wrong with the 241. I ran one with a slip yoke eliminator behind the 6.2/4L60 and the Cummins/SM465 before I swapped to the NV4500. Had I not already had the round pattern 205 I would have continued to use the 241, albeit with a new Morse chain installed. The 205 is definitely more durable, but the 241 is just as strong as a Ford 205 from a torque-handling standpoint and has a better low range ratio. As long as the chain is replaced when it gets sloppy, the aluminum case is protected from damage, and the fluid is kept full and changed at proper intervals, it will last as long as the rest of the truck. The only mod I consider mandatory for a 241/243 is a slip yoke eliminator (sold by JB Conversions), since slip yokes are dog's breath and increase the odds of case breakage, The 2WD lo mod is only needed if you actually have need for 2wd low range when the hubs are locked in.

Ford 205's are weaker than the Chevy/Dodge pass. drop 205's due to the location of the PTO opening. That said, the only time they ever break is behind modded diesels doing sled pulling, or very rarely in rock crawlers behind very healthy gas engines with a crawler box between the trans and t-case and 42"+ tires with chromo axle shafts. Even then it's usually something else (like a chromo shaft, R&P, or the 205 output shaft) that fails before the case, so I wouldn't hesitate to use a Ford 205. They're still much stronger than an Atlas. The big advantage of the 205 is that there are no chains to stretch, so they are very low maintenance; just make sure it has fluid and change the fluid at the proper intervals. The other big advantage is they are easily twin-sticked, allowing you to run 2wd hi or low, front or rear. The disadvantage of the 205 is the meager 1.96:1 low range ratio (easily fixed with a crawler box) and more parasitic drag (minimized by filling with Redline MTL). My big ol' Blazer with nonexistent aerodynamics has gotten over 18mpg combined city/freeway with the 4500 (filled with Syntorq) and 205 (filled with MTL), so I don't think the drag vs a 241 is much different.

 

[4speedfunk]

On my last trip to the Badlands, I met a guy trying to completely destroy his XJ (not uncommon around there) on a gigantic pile of rocks. He showed me his rig, and his transfer case was some sort of half-and-half 241/Dana 300 thing. Anyway, it used the front half of a 241 with the rear half of a 300...pretty cool. It had like a 6:1 low and also twin-sticks. We talked at great length about it but, I was in over my head as my t-case knowledge is very limited. I guess its a common kit that Jeep guys run. His was a drivers-drop and I'm not sure if it can be had in a passenger-drop. My Burb will remain d.s. drop but, I was thinking this rig might work good for the Hummer (p.s.).

Once you go solid axle on the H3, you have lock-out hubs, so it opens up the door for a true 2WD mode...if you can find an appropriate p.s. drop t-case. I've seen a Colorado with a 241 swap but, I really hate to give up the 4:1 low of the stock BW3394 case. So, I'm on the fence about it. MaxPF...any suggestions on a 2WD passenger-drop case with a 4:1 low range? I would prefer something with a VSS sensor to keep my electronics happy.

 

[SuperBuickGuy]

Dana 300 with a Novak 32 spline output shaft. It's got provision for an electronic speedometer (it's exactly what I built for my Land Cruiser). You can get 4:1 gears for a Dana 300. All in, cost-wise, you're looking at about $1700. Best of all, you can get an adapter from the 4L60e to the Dana 300, with 32 spline outputs, 4:1 all-gear it'd be the cat's pajamas for the H3... they can be flipped, but their normal place is passenger side drop.

Since it's a popular case, you can get cable controls, twin stick.... I can't imagine a better set up for the H3 with a solid axle... or for anyone who wants to decouple the front from the rear.

sorry Max, didn't mean to steal your post

 

[MaxPF]

On my last trip to the Badlands, I met a guy trying to completely destroy his XJ (not uncommon around there) on a gigantic pile of rocks.

Yeah, I don't get it. If you want to bash rocks, build a tube buggy. A lot of these guys seem to enjoy destroying perfectly good vehicles...

He showed me his rig, and his transfer case was some sort of half-and-half 241/Dana 300 thing. Anyway, it used the front half of a 241 with the rear half of a 300...pretty cool. It had like a 6:1 low and also twin-sticks. We talked at great length about it but, I was in over my head as my t-case knowledge is very limited. I guess its a common kit that Jeep guys run. His was a drivers-drop and I'm not sure if it can be had in a passenger-drop. My Burb will remain d.s. drop but, I was thinking this rig might work good for the Hummer (p.s.).

It's a 241 crawler box. It doesn't use the "rear half" of a D300, since D300's don't have split cases. It's a kit that uses the planetary section of a 241 to make a crawler box which bolts to the front of the D300. This effectively makes a 4-speed transfer case. There are also versions that bolt to a 205. These setups have serious drawbacks though, as do crawler boxes that use the 241 planetary set in a billet case like the Klune V and the ORD Magnum. The problem is that they have very limited lube capacity and the lube overheats under sustained speed (i.e . driving down the highway). Also, the 241 gearset is designed to be fed pressurized oil through the shaft from the oil pump on the output shaft. The crawler boxes no longer have the oil pump and try to rely on splash oiling, which doesn't work very well on a planetary setup. In particular the input pocket bearing gets starved of oil. If you put enough oil in to get adequate lubrication it gets whipped up into a foam at road speed and pukes lube out the vent.

Once you go solid axle on the H3, you have lock-out hubs, so it opens up the door for a true 2WD mode...if you can find an appropriate p.s. drop t-case. I've seen a Colorado with a 241 swap but, I really hate to give up the 4:1 low of the stock BW3394 case. So, I'm on the fence about it. MaxPF...any suggestions on a 2WD passenger-drop case with a 4:1 low range? I would prefer something with a VSS sensor to keep my electronics happy.

Other than an Atlas, I can't think of any p-drop case that gives 4:1. You can get 4:1 out of a 203-205 doubler. The 203-205 is a kit that turns a 203 range box into a crawler box, which then bolts to the 205. Because the 203 range box has a 2.01:1 low range, and the 205 has a 1.96:1 low range, running both in low range effectively gives you 4:1 (technically, 3.94:1, but everyone rounds it to 4:1). However, because both are essentially 2:1ish, you end up with a 3-speed box rather than a 4 speed. The main advantage of a 203 crawler box (which uses BIG helical gears) over a planetary box is that it has no oiling issues since it is operating with the same oil sump as it was designed. Since it holds much more fluid than a planetary box, it won't overheat. The downsides is that it adds 9 inches to the length of the trans-tcase assembly, and it is quite heavy and needs it's own crossmember and mount. If I decide I need more gear this is the way I am going to go. I already have two 203 range boxes, just in case :thumbs:

Oh, and of course you can easily mod a 205 to run a 40 tooth reluctor and pickup.

Dana 300 with a Novak 32 spline output shaft. It's got provision for an electronic speedometer (it's exactly what I built for my Land Cruiser). You can get 4:1 gears for a Dana 300. All in, cost-wise, you're looking at about $1700. Best of all, you can get an adapter from the 4L60e to the Dana 300, with 32 spline outputs, 4:1 all-gear it'd be the cat's pajamas for the H3... they can be flipped, but their normal place is passenger side drop.

Since it's a popular case, you can get cable controls, twin stick.... I can't imagine a better set up for the H3 with a solid axle... or for anyone who wants to decouple the front from the rear.

sorry Max, didn't mean to steal your post

You can find good used Atlases for less money than that. Also, a 203-205 doubler kit runs $770. Figure a couple hundred for a 205+rebuild parts, and Free-to-$50 for a 203 (or just the 203 range box). As long as the extra length isn't an issue, you get much greater strength and 3 speeds for $700 less. 205's are already 32 spline rear output, and the GM 30 spline front output is fine for most folks. If not, 32 spline front outputs are available new or can be pilfered from a Ford 205. 205's are easily twin-stickable, easily converted to electronic speedo (unless you are lucky enough to find the rare, elusive 1990-91 205 that already has an electronic speedo housing) and the 203 range box can be had with either 27 or 32 spline inputs.

The ORD Magnum box is $1990 and gives you a ridiculously strong 4 speed t-case setup with 1:1, 1.96:1, 2.72:1, and 5.33:1 ratios.Being as it bolts to a 205, you get all the 205 benefits. My only concern is how well it oils and how hot the oil gets. It has been tested on road trips and been OK, but I guarantee the fluid will need to be changed at least as often as the engine oil. No idea how long it will run before it needs a rebuild. Like I said, for a DD or a rig that sees a lot of street/highway use I think the 203-205 is a better setup. 203-205 kits or even complete setups are available fairly reasonably since they are no longer "cool" - guys who have to have all the cool stuff sell em off to get a Magnum setup or a 4 speed Atlas. :roll:

 

[SuperBuickGuy]

I agree to what you've said, except, any doubler is a bunch longer then a 300, even the Atlas is longer. The other issue about the Atlas - I've a pretty good idea on prices because I started looking for a decent priced one when I started my FJ40 build in August of 2014.... while there are the occasional deals, $1700 is the baseline to judge whether or not the Atlas is a good deal. If you want to talk deals, I've seen several D300s in the $700 range with all the mods already done. The lowest I've seen an Atlas for was 1500 and it needed work - I figured that all in, it would have been just under 2k YMMV

 

[MaxPF]

I agree to what you've said, except, any doubler is a bunch longer then a 300

That's true. Whether it's a problem depends on the particular rig and how short your rear driveshaft ends up being.

even the Atlas is longer.

Even if it is I can't imagine the 2 speed Atlas is more than an inch or two more than the shortest D300 setup.

The other issue about the Atlas - I've a pretty good idea on prices because I started looking for a decent priced one when I started my FJ40 build in August of 2014.... while there are the occasional deals, $1700 is the baseline to judge whether or not the Atlas is a good deal. If you want to talk deals, I've seen several D300s in the $700 range with all the mods already done. The lowest I've seen an Atlas for was 1500 and it needed work - I figured that all in, it would have been just under 2k YMMV

$1700 for a clean used 3.8:1 or 4.3:1 Atlas is a good deal, and I have seen more than a few in that range. More often than not they were removed because the owner decided they really needed a 4 speed Atlas. Their loss can be your gain! $700 for a D300 with all the mods is a smoking deal! The D300 is the same strength as an Atlas (the Atlas is based on the D300), and while not nearly as strong as a 205 it is still more than strong enough for an H3 unless you have a lot of HP and really big tires.

 

[MaxPF]

So, last time I updated the thread I was about to get some exhaust going. It's just your basic 3" aluminized system,starting with a downpipe:

I decided to reuse my Magnaflow muffler:

It really tones down the exhaust and eliminates any in-cab drone despite being a straight-through design:

Complete exhaust system:

Gotta wrap the downpipe to keep the heat down:

A few installed pics. I had to route the exhaust on the outside of the trans crossmember due to lack of clearance inside:

And, of course, the honkin' 4" tip!

 

[alrock]

I think you're missing a driveshaft

 

[06 H3]

What t case is that? Saw it in your exhaust pics

 

[MaxPF]

I think you're missing a driveshaft

I got a driveshaft on the rear! Geez, how many do I need!

What t case is that? Saw it in your exhaust pics

NP205. :thumbs:

The 205 picture show starts on post #30

 

[06 H3]

Can never go wrong with an old school gear driven case. I'll go back and look at that post.

Is this up and running now?