OBS Cummings swap

6.0 p-stroke · Feb 27, 2013

A spacer would work but it would move the turbo that much closer to the airbox, I don't want to have to worry about it getting hot and melting.
No Colton, I keep forgetting. If I did swap the exhaust housings I'd have to clock the comp housing clockwise which will make a funky IC pipe with a tight radius coming off the turbo to the IC. If we use an industrial manifold then it's basically a straight shot to the IC and the downpipe will be much easier to fab and it'll eliminate almost 90 degrees of bend on the downpipe. I think it's a better choice all around to run the industrial manifold, we wont have to worry about port matching a manifold or mismatched housings and alot less plumbing to run. My dad found a couple for less than $100 bucks, it just seems like the better route for simplicity.

Idiesel · Feb 27, 2013

I see. Just a thought. I think it will look better with a industrial manifold anyways.

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6.0 p-stroke · Feb 27, 2013

I've been trying to figure out a way to get the tach to work on the dash, after talking to Diesel Conversion Specialists (fordcummins) it seems the only way it's going to work is with their kit which is around $250. I would think there would be a way to make it work with what we've already got by splicing into the wiring harness, we've got both harnesses from each truck, does anyone have any information on how to make it work without buying the kit?

Matt_P · Feb 27, 2013

6.0 p-stroke said:
I've been trying to figure out a way to get the tach to work on the dash, after talking to Diesel Conversion Specialists (fordcummins) it seems the only way it's going to work is with their kit which is around $250. I would think there would be a way to make it work with what we've already got by splicing into the wiring harness, we've got both harnesses from each truck, does anyone have any information on how to make it work without buying the kit?

The biggest issue with making it work by just splicing in is that the ford ECM and Dodge ECM require different frequencies for the tach, A 12v only sees 2 pulses per engine revolution which it takes off the harmonic balancer with an engine speed sensor mounted on the timing cover. Im pressure sure the 7.3 takes tach pickup from the CPS and I know the tone ring on that has a lot more than two marks so if you spliced it would have the frequency readings all mixed up and not read properly.

The tone ring just ends up giving you the proper amount of pickups to recieve the correct frequency so then you can then just splice into the ford harness and recieve the correct pickup. It does suck to have to spend that much on something so simple though, the other option would be if you can figure out a way to convert the frequency

Idiesel · Feb 27, 2013

Is there a way to rob the tone ring off the 7.3 or is it welded to the crank?

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6.0 p-stroke · Feb 27, 2013

The tone ring on the 7.3 is on the cam I believe. I'm gonna look at it when I get home. I don't think it would be hard to make a bracket to hold the CPS, there should be some way to mount the tone ring from the 7.3 onto the crank pulley, assuming I can get it off the 7.3.

Lamont_24 · Feb 27, 2013

Yeah about the spacer I think the guy dyna matted it so it wouldn't melt.

But if you talk to ford cummins all they're going to want to do is sell their products to you.
Could you fab up something to run an aftermarket tach in the stock dash? I wouldn't think it's possible but just an idea

6.0 p-stroke · Feb 28, 2013

After thinking more about using the 7.3 tone ring and CPS to read RPM I don't think it's going to work. On the 7.3 it's made to read off the cam which is spinning 4 times slower than the crank, so if I were to mount it on the crank it would read 4 times the RPM than it is actually turning. Atleast this is how I'm seeing it in my mind, please correct me if I'm wrong.

Matt_P · Feb 28, 2013

6.0 p-stroke said:
The tone ring on the 7.3 is on the cam I believe. I'm gonna look at it when I get home. I don't think it would be hard to make a bracket to hold the CPS, there should be some way to mount the tone ring from the 7.3 onto the crank pulley, assuming I can get it off the 7.3.

Yeah making a bracket shouldn't be hard and if you can make a tone ring or get a time ring to mount on the balancer like a tach kit you can buy then set the correct gap for the sensor then you'll be good to go.

Cat_rebel · Mar 1, 2013

What if you used the harness from a 92-94 IDI & tied the factory tach sensor into the one off the cummins?

6.0 p-stroke · Mar 11, 2013

Cat_rebel said:
What if you used the harness from a 92-94 IDI & tied the factory tach sensor into the one off the cummins?

That might work, my dad has a few ideas he wants to try before ordering the kit. He also found an Industrial style manifold up in Ohio for $75 bucks, they're shipping it out today. We'll be out of town starting Wednesday so it'll be next week before we pull the engine back out and massage the firewall and install the manifold.

YOUNG GUNS15 · Mar 12, 2013

good looking swap, Preparing to do the same with my 97 OBS f350 with a 460 and a ZF5.

Injected79 · Mar 13, 2013

On your exhaust manifold issue, i used a 3 piece for a 24v and flipped it so the turbo sat on top. I ran a gt3788r with no issues. I did put a 1 or 1.5 inchbody lift on the truck. On the tach, when we did my cousins bronco, his dad used the factory 302 ecm, and machined the harmonic balancer to have the correct pulse count. It works great.

6.0 p-stroke · Mar 18, 2013

The industrial style manifold showed up on Friday, two of the studs are broke off but we should still be able to get them out, it was a little over $90 bucks after shipping. I'm too worn out from an event this weekend so I won't work on it until later this week.

ImageUploadedByTapatalk1363640491.154913.jpg

davey99ps · Mar 18, 2013

It's coming along nice, can't wait to see the finished product

dzljon · Mar 19, 2013

6.0 p-stroke said:
Does anyone know of a place to get the fan hub bearing? Dodge wants like $320 bucks just for the bearing! We've called around to a few places and looked online and no one else seems to carry that bearing.
View attachment 14584

http://www.thebigbearingstore.com/radialballbearing.html