I currently have 4.10's and I think at highway speeds I would be a little high, like in the 2100-2200 range. I know the 6AT is a little happier at high revs. But its no longer produced and parts are hard to find. So it seems a regear is necessary. I would like to run larger than stock tires for my clearence in the back 40 acres. Planning on 33's with 3.73s and an NV3550 trans. Should be about 1950 ot 2000 at 65 mph. With your experience with the engine do you think it would be happy there?

Whats the fastest rpm the engine can run?

 

The engine is really smooth above 1700 rpm. I've been cruising in 4th gear at ~2000 rpm on the 55 mph county roads (actually going 60mph at 2000 rpm in 4th gear which is a 1:1 ratio for the AX-15). It's really smooth all the way up to 2600 rpm. I've modified the screw which sets the high rpm limit (discussed earlier in this thread) and can now rev up to ~3100 rpm. The spec sheets show the max rpm limit of 3250 rpm being where the "destructive harmonics" start to occur. I rarely go over 2600 rpm unless I need to accelerate fast and merge onto the interstate. The times I'm above 2600 I'm not paying attention to how smooth the engine is as I'm usually focusing on merging with traffic or something like that.

I put a mechanical oil pressure gauge on a couple days ago. Bought a cheap Sunpro 100 psi gauge from the local parts store. Yikes. I see why I was blowing those sending units. After the engine is warmed up the idle psi is ~50 and running down the road it peaks about 80-85 psi. However, when the engine is cold I'm pegging the 100 psi gauge even at idle. I have a 150 psi mechanical gauge on order. One of the extra documents I got from Cummins shows an obscure reference to the max cold engine oil pressure being 135 psi (I was wrong early when I said 138 psi). I believe it. It's just so much higher oil pressure than any engine I've ever worked with before.

Oh, and I'm using Shell Rotella 5w-40 synthetic engine oil.

 

thats good info there. I was under the impression that this thing could only spin to like 2600 and in a car thats not very good. But 3000 is alright. What kind of oil pressure gague and sender do you have on order?
Where do you get oil filters at for your engine, I assume the only place that has them is the Cummins dealer, they are not something you can get at Auto Zone?
How ofton do you change your oil?

 

Have a 150psi VDO mechanical gauge coming. It doesn't have a connection kit with it, but it has the same connector on the back as the Sunpro gauge so I'm gonna re-use the same tubing/connector.

If you look at the horsepower/torque plot in the yahoo photo section you can see the hp is flat above 2600 rpm so you're not gaining any more power with the higher rpm's, but it's sure nice to have that extra rpm room for certain driving situations (like merging onto the interstate).

I get the filters through the local Cummins dealer in Cedar Rapids. Pretty certain AutoZone won't carry these

The manual says to change the oil for the first time at 250 hrs or 3 months. I changed it at ~ 500 mls (2 weeks) and then last weekend at ~5200 mls (~5 months). After the first change I believe the manual says every 500 hrs or 6 months (but I don't have the manual with me so can't say for certain). The oil was just starting to get a little dark at the 5000 ml point and used very little oil (the oil level dropped from the full mark to about 1/2 way between the full point to the low point during the 5000 mls). I'm using Shell Rotella 5w-40 synthetic. With an oil/filter change in takes about 7.8 gallons to get to the full mark.

The manual also recommends checking the valves at250 hrs, although from what I've gathered this is rarely done at this point.

 

Holly cow, I ment 7.8 quarts, not 7.8 gallons for the oil fill! Sorry about that.

 

That would be amazing if a little engine took over 7 gallons of oil, that rotella stuff is expensive. A person I know uses it in his 2ltr turbo gasoline engine. Don't really know why he does.

I like the top mount intercooler you hooked up, looks like it belongs there. I was thinking of getting some of the silicon hose the tuners use and hooking up a huge front mount intercooler. I wonder what the effects would be on your EGT's if you did that.
Do you have anymore pictures of your jeep you can post. Espically the rear crossmount for the trans/ t-case? Intrested to see what you did there.
-nate-

 

Morning Nate

I didn't have to modify anything with the transmission mount or the transfer case. In fact I left those in the jeep as I pulled out the gas engine and put in the B3.3T. It would have been easier to mount the engine to the transmission if they were both out but it didn't take too much wiggling to get them to mate.

The comparisons I read on top mount versus front mount intercoolers showed the top mounts usually are extremely close in terms of cooling capacity at velocity, but worse in traffic/slow moving conditions. However the shorter routing of a top mount usually provides less turbo lag. A front mount intercooler would be a bigger benefit if you are doing a lot of slow moving driving (rock crawling for example). I would caution not to go too big and have too long of connection tubing as you'll introduce turbo lag. There's many great guides on the net for properly sizing intercoolers. With my little top mount intercooler and the reverse cowl induction setup I'm running I get lots of air flow through the intercooler at speeds over ~20-25 mph.

 

Yea, turbo lag sucks. I would be really cool if supercharged diesels were popular. I wonder what those would be like??!! Alot of the tuners in the area run hige front mount intercoolers on little 2L engines. I would say they are 8 inches tall, 22 inches wide and probally 2-3 deep. Do you think an intercooler that big would be to big for the cummins. As the engine being so much bigger than the import tuners, I would run an even bigger intercooler. But when it comes down to it I will only have so much room in front of the radiator.

Have you played with the boost at all. Do you think some more air would lower the EGT's. If you have turned up the fuel what do you think would happan with an extra 2-4 psi of boost?
http://www.bellintercoolers.com/
check out this webiste, if you see something that you think would be best.
To be honest my plan was to just get the biggest one I could fit in the space I have left over after the swap.
I guess if you get a racing intercooler they have much lower pressure loss and have a higher cooling efficency.

any thoughts.......?

 

Regarding the EGT's and boost: I've run out of injection pump tuning room before I ran out of boost or intercooler capacity with the small top mount intercooler. With the last injection pump tweak I'm seeing about 14.5 psi max boost. If you use the 10 psi per 100 hp rule of thumb then the turbo should support about 140 to 150 hp. The max EGT's I'm seeing are about 1100 deg pre turbo. If I turn up the injection pump any more the rpm's start hanging (see previous posts for description of this issue). I need to get the accelerometer back and remeasure to see where the B3.3T is at, but with the winter fuel it wouldn't be an apples to apples comparison. I'm estimating it's somewhere around 300+ ft-lbs of torque and 120-130 hp (this isn't a whole lot and doesn't require a large intercooler). I don't see any reason/benefit to go with a front mount intercooler for the way I drive. The boost response is near instantneous and the EGT's are well within the safe level. Plus the used intercooler was super cheap. If I was doing a lot of rock crawling then I could see a benefit from the front mount intercooler.

I've been to the bell intercooler site. I was going to order from them before I found my intercooler for sale on ebay.

 

Got an email back from Cummins regarding the oil pressure. Here's the quote from the first line of the email (then it goes on to quote the nominal and min pressures):

"Oil pressure's on the B3.3 are higher than typical 4B/6B engines. Here's what the data sheet and performance curve says for a Tier 2 B3.3T 85hp @ 2600rpm engine. The max oil pressure spike on a cold engine is 135 psi.
"

With the new 150 psi pressure gauge I'm seeing peaks of ~120-125 psi when driving through the gears on a cold engine. When the engine is hot the pressures are about 45 psi at idle and ~75-80 psi at higher rpm's.

 

your engine has very high oil pressure. On my jeep engine I might get 60psi cold.
I was looking at the QSB 3.3, what do you think about that engine. I like the common rail injection that it has, its got like 304 ft-lb stock. Alot more than any 4.0 Jeep engine, unless you put on a turbo or blower.
I think with the QSB I could get a custom remap and probally get 200hp and 450 ft-lb? Wow would that be a trip.
Do you know if there is a way to run Aux items off the front pulley drive. Like an add on pulley for the powersteering pump. Thinking of taking the one off my my jeep engine and making a custom bracket and just running a belt to drive it.
let me know what you think?...

 

As a rough estimate the 5.9 engines can make over 1000 ft-lbs with enough tweaking. Scaling for the same displacement would put the 3.3 over 559 ft-lbs. However, I don't think there's enough aftermarket parts for the 3.3 to make this happen

It would be a good idea to consider the limits of your drivetrain as well. On my AX-15 I wouldn't want to go much higher than where I am at. If you had a stronger tranny and axles then . . .

I know there are custom programming options for the QSB version to set various hp/torque curves, but I'm not aware of how high they would take the engine with it's stock injectors, turbo, intercooler.

I discussed the power steering route I would take earlier in the thread. It involved taking an off the shelf SAE hydraulic pump and a pressure regulator and mounting it to the engine and pipe that into the steering box. The standard SAE hydraulic pumps are very reasonably priced. There are lots of bolt holes around the engine so I would imagine something could be fabbed to hold the pump.

 

Very interesting read, just caught up these last 6 pages just now! Great install. I am on my second 4BT into a Land Cruiser. I like the idea of the smaller Cummins and that is an excellent price on a brand new one. 305 ft/lbs BHP powered my wagon with 35" and 4.1 /NV4500 .73 overdrive very well assuming my used engine was still making 305 ft/lbs, 120 hp as it was supposed to. I too became addicted to the power. Some people report similar mileage with their 3.9s but most are mid-high 20s, I personally was about ~22ish, lower over 75-80 mph which is tempting not to do out here on the desert highways. My gearing allowed about 83 mph at ~2250 rpms, my pump was governed very low and it felt like it was screaming even at that low RPMs. I never adjusted higher, but have and plan to on this next 4BT.

Anyway, very enjoyable read. Also for what its worth, my oil pump "broke in" and I started seeing more normal oil pressure numbers after some time, at first I thought maybe something was wrong, I never got about maybe 80 though with dyno oil. I would not be too scared of the oil pressure numbers for such a new engine.

Again congrats on it, I have thoroughly enjoyed your thought process and rationals behind the power and installation techniques and nice to actually see a phoenix castings adapter in a photo, excellent!

Andre Shoumatoff
(List owner for 4BT swap yahoo group list)
http://autos.groups.yahoo.com/group/cummins4BT/

 

Thank you. Nice picture of the Landcruiser at your yahoo group. Thanks for the info on the oil pressure.

 

I have herd that the 4bts arnt that great in a land cruiser. They have very low red lines and are loud as hell and shake around alot. They must not be that bad if you are proceeding to do another one. I kinda like the 6AT, seems to have a little better manners if you believe what you read, but then again, where can you get parts for them?
TDIwyse: I would like some more knowledge about these SAE hydraulic pumps, they will do the job of a power steering pump. Do you think I could use the power steering pump in my jeep know with a custom bracket?
I just cant find a way to put a second pulley on the engine.