who installed a cummins intercooler?

[HANK1948]

Awhile back I saw a post (with pics) of someone installing a cummins intercooler in there 88-97c/k and moved the rad toward the engine and modified the rad support, it seemed to work the intercooler was big eniugh to go around the radiator but I tried searching the 6.5 posts but cant find it? did anyone remember this?

[Andy Chesek]

I just dropped my truck off yesterday at the shop. Having a '98 Dodge Ram intercooler (got off eBay) modified and installed behind the grill.

At first I was going have just have the guy turn the upper intake around (saw someone's truck who did that, can't remember who), but then when I actually thought for a half-second I decided I wouldn't want to muck with that when I want to change the fuel filter. Saw pics of Grape's project and liked the simple setup he's got, so I'm getting an upper intake fabbed up, too.

I don't have the time to be at the shop while the work's done, but I'll be happy to share some pictures of the end result when I get the truck back.

[rjschoolcraft]

Fluid flow does not like sudden changes in cross sectional area. The intake on Grape's engine will have high exit losses as the air moves out of the tube and into the plenum. Their will be boundary layer separation and a lot of turbulence. The transition designed into the factory inlet is there to reduce those exit losses and minimize the boundary layer separation upon entering the plenum. Some have said that the flow is being squeezed down; it is not.

The cross sectional area at the entrance to the plenum is 4.469 in^2. The cross sectional area of the tube is 3.142 in^2. The flow area was increased. This increase is more than would have been necessary for Reynolds number effects, so it is actually being used to slow the air flow down before dumping into the plenum. Again, to reduce losses.

The airflow is not being squeezed at all, as is being discussed. The shape is being changed and it is being expanded. All goodness for reducing inlet loss.

The factory inlet is better than the one shown in the image by Grape.

[Andy Chesek]

RonnieJoe,

Saw that post coming a mile away... read it earlier on another site. I'm in no way discounting what you are saying, just a dumb computer geek here... more of a seeing is believing kinda guy, too. I'll still have the stock piece, and things could be tweaked to make it work with the intercooler piping if need be.

My question is, who has fabricated a custom upper intake plenum for their 6.5L before? Has it been tested in the real world? How did it compare with the stock piece?

There's a dyno about 10 minutes up the road from me, could I learn anything by making a trip there?

If this custom intake piece doesn't work out, I'm not losing out much. I'm willing to make a small sacrifice for the sake of 6.5L owners.

[rjschoolcraft]

Dyno trips are always useful!

[grape]

ha, somebody finally asked. 1st rule in performance engines........"you aint lookin in my intake manifold." You guys don't give me enough credit, do you really think I did all that work and just dumped a 3" tube in the plenum? ;)

small tip, air won't stick to anything more than a 15 degree break, obvious in the world of 5 angle valve jobs, 60-45-30 et.

[rjschoolcraft]

I really didn't doubt you, but the other guys talking about this were about to make a big mistake. That is the context for my comments.

[HANK1948]

So, grape what did you do to direct the air in the plenum? did you fab up a divider in the plenum to redirect the air down to the runners?

[Barry Nave]

I'd like to see the filtered air piping

[Andy Chesek]

I got a call yesterday from the shop owner, and the word was an employee of his wanted to just hack up the stock intake piece and stick a 3" elbow on top of that. That way he wouldn't have to tap new holes for the MAP and IAT sensors. After some discussion, it was decided that the stock piece will be used, just spun 180 degrees. I'll just have to remove it when I want to get at the fuel filter. 6 Bolts isn't a big deal.

The passenger side battery will probably be relocated, and a 180 degree elbow will be used from the air filter in its stock location to the turbo. Should be done Monday or Tuesday, barring any problems.

[MTTwister]

Hank - maybe he used one of those "Turtles" in the bottom of the intake.

[More Power]

Here's how Andrew Ashwill did it.

http://www.thedieselpage.com/images/ashwill31.jpg

MP

[Robyn]

From someone who runs large diesel trucks.
Pull the phoney little fuel filter out of the valley and toss it in the trash can and install a nice moderate sized filter elsewhere in the engine bay that you can get at without worrying about crawling over the engine. Also a commercial truck filter will have a bowl on it so you can see if you have water and a drain to get rid of it.
I have a raycor on mine along with a Small Cat final filter before the pump. Tad overkill but there is no such thing as too clean when it comes to fuel. I always hated that mess of fooling with the filter back there in that hole anyway.
Robyn

[GMCfourX4]

Hank;
You might be thinking of my intercooler install (at least the part that I've finished so far...) I still haven't gotten around to getting the tubing done. I decided that the best thing for me to do was to install the intercooler upside-down, in the spot where the radiator lived originally. I then fabbed up some new lower radiator brackets, cut the radiator support to make room for the intercooler, removed the clutch fan and cut the extra waterpump shaft off, and cut/ground the Dodge mounts from the intercooler. I also moved both batteries and fabbed up a new air filter box that fits right behind the headlight where the "snorkel" used to be. It was a LOT of work. I searched for the post I had made with pictures, but I can't find it anymore, for some reason (it was over a year and a half ago, and I think it was before the server problems). If you have any questions on it, let me know.

RonnieJoe and Grape:
I am planning on making an upper intake similar to the one in Grape's pictures when I get my intercooler connected, but it sounds like there's something I'm missing as far as the airflow angle goes. What would be my best alternative to get it to work properly? Grape, what did you do on the inside? I will need to get rid of the factory upper-intake due to space constraints (I need to have my tubing return on the driver's side of the engine).

-Chris

[JoeyD]

So is the picture MP posted not a good idea? Maybe if the intake was to start out at 3 in and end up at 5 or 6 inch at the manifold adapter it would work better?

[HANK1948]

I work at Roush Racing in MI were we did all the nascar motors for our race teams, also we have alot of experience in turbos , we were undefeted for years in Trans Am (turboed v-6 and L-4's) so I was talking to my buddy I work with that did all the motors for our Trans Am teams and he said pick the biggest intercooler you can fit in the truck, also keep the same dia. of the turbo outlet to the intercooler and when exiting the intercooler use the same dia. as the intercooler (mine is 3in.) and make a nice smooth transition to the plenum (as the pic. MP has posted) we dont need to worry about more turbo lag because were not racing