85 1 ton Dually- Cummins Swap

[tpull123]

What Alternator did you end up using and what are you doing for a tach signal?

[cubicdollars]

I am using the chevy alt from a 1990 Suburban alon with the AC Compressor, I do not have a tach in the truck but I think there is tach adapters availble.

[WilliamBos]

Beautiful job.  Starting to see more swaps like this, and for good reason, nothing beats the simplicity of a mechanical diesel.

How loud us it in the cab??  Probably not any louder than a first gen. Ram I guess??

Excellent work.

[Edahall]

Beautiful job.  Starting to see more swaps like this, and for good reason, nothing beats the simplicity of a mechanical diesel.

How loud us it in the cab??  Probably not any louder than a first gen. Ram I guess??

Excellent work.

FYI:  The Cummins from the first Gen. Ram I had a VE pump that ran quieter than the Second Gen Ram from 94-97 that had the P-pump.  Then when they went to 24V in 98, the engines got significantly louder.

[WilliamBos]

Beautiful job.  Starting to see more swaps like this, and for good reason, nothing beats the simplicity of a mechanical diesel.

How loud us it in the cab??  Probably not any louder than a first gen. Ram I guess??

Excellent work.

FYI:  The Cummins from the first Gen. Ram I had a VE pump that ran quieter than the Second Gen Ram from 94-97 that had the P-pump.  Then when they went to 24V in 98, the engines got significantly louder.

Thanks a lot.  I never really though about the injector pump being so heavily related to engine noise.

[cubicdollars]

I put full exhaust on mine and it helped quiet it down but it's still pretty loud, You can talk but you have to speak up a little more   My cab is pretty rusty so when I find my new cab I plan on spraying on Lizard Skin on the Inside and outside firewall as well the the floor. That should help a little.

Thanks
Dan

[tpull123]

On mine, I did about a 30% coverage of quick roof, topped with closed cell foam, and a layer of Mass loaded vinyl......Hopefully in a 3-4 weeks I can let you know how that quieted down.    RIght now mine is loud too, but no side windows, exhuast, and hood kind of kill any relevance at this point!

[cubicdollars]

Let Me know how that works out for you.

I was planning on Bringing my dually and trailer on its longest trip to date last weekend but as I was about to pull out of town I noticed a bad fuel leak, Earlier that day I finally filled my other tank aftyer being drained and I switched tanks to make sure I was ulling fuel properly, Well evidently The valve was stuck in 1 position for so long I split an internal o ring or something it was leaking out of the bottom weep hole of the Valve I will replace the switch and try it again, Thank God I noticed it before I left on the 200 mile trip

[big bear]

wow, sucks to hear man..like you said, least you had it happen at home

[NevadaNeal]

I am soooo copying you...thats just awesome. 

[cubicdollars]

Thanks Man

Well Made my first long haul no problems finally I got 200 miles out of 1 tank thats twice as much as before I figure around 11 mpg with a trailer. it ran 210 the entire time and did not get warmer than that even when I was pulling hills. I still have a laundry list of things to do. Finish AC installation, Time the fuel pump, check and set valve lash, and bumb the fuel plate.

[DustyRusty]

Very nice project build.  Great job of photo documenting and writing it up.  Keep up the good work.

Since the Cummins is so heavy, how are the front springs taking the additional weight?  Or is it too early to tell?

Rusty

[tpull123]

I got the same clutch master cylinder, did you have any trouble with firewall flexing?     My cab was an automatic, so not sure if the manual cabs had a different support there or not?

[cubicdollars]

Hey Guys, Thanks for the compliments

So far the front end is ok, I replaced the old springs when I lowered it with Bell Tech springs so I think that helped, I would eventually like to install airbags in the front but not anytime soon.

My Ftruck always had a hyd clutch and when I installed the new one it pretty much bolted up except for the push rod, I have not noticed the firewall fleving on mine but I also have never looked for that condition. I can tell you the clutch pedel force feels about the same between the 2 hyd slave cylinders.

thanks
Dan

[Edahall]

I got the same clutch master cylinder, did you have any trouble with firewall flexing?     My cab was an automatic, so not sure if the manual cabs had a different support there or not?

My 1990 Suburban originally had an automatic and now that it has been converted over, I don't notice any firewall flexing.  Is your clutch pedal unusually stiff?   If so, that might be the source of your firewall flexing.  You can change the firmness of your pedal with a clutch master cylinder of difference bore size.  There's a thread on this if you're interested.