So there just so happens to be a replacement for displacement, and it's turbochargers! Yes, we could have swapped in a Cummins 6 cylinder, but time and budget are a factor and we ended up rebuilding the Cummins 4 cylinder. Besides, my engine hoist couldn't pick up the 6 cylinder, so that was the final deciding factor, and I'm sticking to that. But I bet we could squeeze just a lil bit more out of the lil engine that could, or couldn't.
The old setup has a turbo, stock from the factory for this van application. But as in other factors in life, size does sometimes matter. And the old little one got the job done for the van, but she wants to get up to speed faster sometimes and in a more efficient manner. You can also see the air intake setup. Not sure what went on there, but someone took some scrap metal brackets and exhaust pipe and welded up this horrendous attachment for the air filter, bolted to the exhaust manifold. I'm very glad to throw all that into the trash.
So first thing is first, mount the new turbocharger. Of course it barely clears the exhaust manifold and butts up against the oil filter. No way to get a rubber elbow on that to clear it. This turbocharger is much longer than the old one. If we had a 6 cylinder, this would be no problem. Maybe this is a sign we should just get a larger engine?
Options were:
A-get a larger engine
B-get new oil filter plate and turn oil filter sideways
C-get new oil filter plate and retrofit the oil filter into a completely different location
D-flip exhaust manifold upside down and mount turbocharger on top of engine and make new exhaust
E-try to change the angle of the turbocharger to give clearance for intake boot
Well, we went with option E. It was the cheapest and easiest solution. Being a step van, we had plenty of clearance in the engine bay for whatever we wanted. And access all around, front and back. Did I mention how easy it is to work on step vans?
Got turbocharger mounted and the intake boot will clear the oil filter. But now the turbocharger is up and away from the engine block so the oil return won't reach. Simple enough, just need to replace hose with a longer one.
Now that the exhaust manifold side of things is mostly done, lets run over to the intake manifold. The old piping wasn't going to fly. I did all the cfm calculations, which called for 2.6" pipe. That puts us at using 2.75" pipe at a minimum. The pipe coming out of the new turbocharger is 3" and we found an old 3" intake manifold off Ebay at a good deal, so we're using 3" pipe. Yes, there could be potential for some turbo lag, but we're not gonna worry about it. This isn't a race car. Better to go a little bigger than a little smaller.
Cleaned up the new intake manifold and gave it some paint. It was pretty well used and used somewhere that allowed it to get pretty corroded. Surprisingly I was able to get it mounted up without removing the fuel injector lines.
Some people have expressed concern about added heat. So to combat the heated up air from the pressurization of the turbocharger, we're gonna install a intercooler. We picked this 2nd Gen Dodge Cummins intercooler up for $10, score! Not sure how we're gonna fit it, but the tape measure says it will fit in there. Tape measure don't lie right?
Unfortunately, upon cleaning it up, there were 3 small holes. Total bummer. Looks like some kind of bracket was rubbing against the metal. These aluminum tubes are very thin. At first I thought oh well, at least I can use it as a template to make some mounting brackets and order a new intercooler. Ok, great.
But new intercoolers are like $500 and we blew that money on the turbocharger, so we gonna fix these small holes and hope for the best! The aluminum was super thin, and there wasn't a good way to clean the interior, so there was no way I was going to attempt to TIG weld it. So I opted to braze it instead. Was not easy. Aluminum radiators like this are really good at sucking up heat and making it disappear. I had to use quite a bit of heat from the oxyacetylene torch. The middle one had a weird blowout nowhere near where I was heating and working the filler. We'll pressure test it and see if it holds.
Had to move the radiator out of the way and install intercooler down in through the inside of the engine bay. Just fits, with 3/16" of clearance on each side. Now need to fab up some brackets and get some plumbing done.