1990 GMC Suburban ... Cummins Powered

[greguw]

Did the KDP while the motor was on the ground , also loctited the timing cover case bolts and the cam retaining bolts .
Managed to get more lines run and the brakes bleed over the weekend . Also just finished the stainless fuel lines .
Had a set back when it came to the fuel tank , I did buy a new sender unit , figured 20 + yrs that thing would take a crap sooner or later . So ordered a new gas one since it had the return line in place .
How ever I could not identify the coating on the inside of the fuel tank , sucks because its like new , diesel and galvanized do not work well together .
So I ordered a new Dorman replacement for the diesel application .
Thats about it for today .

[Devillusion]

deadly build......taking notes!

[b.eddy's72]

GREGUW........After looking at all the pics and quality job you do I was quite sure that you had not missed a detail like the KDP but I only wished to ask and give the assistance if you were one of the thousands who dont know. Your build is very nice and I wish you the best of luck my friend.

[greguw]

Managed to find some time on saturday to start mocking up the front end , The intercooler is a 99+ ford powerstroke 7.3 intercooler all aluminum , has the inlet and outlet cut , angled and re-welded to clear inter supports .
Still had to cut out some of the outer edge , broke my heart to cut into this new old stock support but it turned out pretty nice , I had to weld on some lower tabs for the intercooler .
The factory grill will also fit ... i was pretty amazed my self ...LOL
Only thing I have to watch is the hood safety latch , may need to be reshape but thats easy fix in need be .
Also figured out I am going to use a original style 3 cool , I had issues with the inlet and outlet but are going to be fine . I had a 1st gen cummins rad , it has the larger inlets but squeezes down to the smaller dia and I'm ok with that .
It also worked out with a belt driven fan ... really did not want a electric ... Keep it simple . I have over a inch between the fan and the rad .
Got some hose adapters and mocked up some of the intercooler tubes .
Still waiting for the fuel tank , have to order some gauges and I think a cowl hood this week .

[walkerb]

wow.just wow

[y5mgisi]

is bad ass! You are doing an amazing job!

[greguw]

Thanks guys ... just stripped the front back off to dress up the radiator support and cut in everything in so I can hang the metal finally .
Also figured out how I am going to trigger the tachometer , I wanted to run a 5" tach ... I'm doing all autometer gauges in my cluster ... since its a mechanical motor it does not put out any type of pulse signal .
I needed to generate a signal the tach could read ... I choose to use a 4 pulse signal ... the front harmonic has 4 bolts that I am going to use as the trigger . Going with a magnetic sensor similar to a pickup in a distributor pickup .
I have to make the mount up once it comes in ... then the pickup will be wired to a HEI ignition module . That will generate a 4 pulse signal that a regular gas tach will read .
Started to tare the front apart for final prep and paint . While I have the sheet off I am installing fuel hoses and sending units for the gauges .
Just finished the pickup mount for the tachometer ... I was not happy with the first design so I went with a dual mount point ... looks a lot better and the pickup should not move .
Got the radiator all painted the other day , looks pretty nice for a truck .

[Dieselwrencher]

Very nice! Could you share some of the wiring details on your tach set up? I just purchased a 5" auto meter diesel tach and it doesn't work. I would like to use a 5" auto meter gas type tach I have instead since my 5" diesel tach is crap and AM has no interest in repairing it for me. Thanks Ryan.

[greguw]

Mag pick up triggered off the four crank bolts.
GM 4 pin HEI module NAPA TP45SB
W= positive lead from the pickup
G= negative lead from the pickup
C= tach lead
B= positive, ign on

Only problem I found now is I have to change my fan plan ... I'm going to have to go electric . I found a 16" flexalite that moves 2500 cfm , new in the box a guy never used for 60 bucks shipped ... not too back considering summit is selling it for $150 .
Then I reconsidered running a first gen radiator but seems the original 3 core will work just have to play the hose game .

[Dieselwrencher]

Thanks man! I was actually thinking of using the guts out of a hei so I could get one working on the cheap. Why do you have to go electric on the fan now? Also, where did you get the pick up sensor from? I thought about using an engine position sensor from a freightliner. It looks a lot like the one you posted.

[greguw]

I would see if you could gut a HEI and remount the pickup , but not sure if it will sense off the bolts . I used a Autometer 5211 ... think its the diesel probe .
Where the crank area is the fan will make contact . I was going drill and tape the outer edge of the harmonic with 1/4 bolts and go that route .
You just need 4 pulse for the HEI to generate the signal ... its like a 4cyl ... tack just knows its getting signal .
I have my pickup set at the outer edge of the bolts but did leave some room for adjustment if need be .
I also set my gap at .040 . The picture is of the second design mount . The first attempt was ok but thought it might viberrate , I basiclly welded a arm to the original tach mount .

[Dieselwrencher]

I thought about having a piece machined with 4 tabs so I could bolt it to the front of the balancer and have clearance for the fan still. Have you thought about doing that?

[greguw]

Just like these guys at destroked ... As I said the only bad part of going the route I did was the fan . The electric is ok with me It does take away from the intercooler but as long as your moving its not a big deal for me .
Could also just machine 2 more notches in the harmonic and that would work .

http://www.destroked.com/parts/tach_kits.shtml

[Dieselwrencher]

I have a few conversion trucks running with electric fans and they work fine. We tow with my Dad's 91 12v F-350 a lot and have only had an issue one time while in Texas when the fans' relay burnt up. It was fine as long as you didn't get caught stopped in traffic for more than 3-5minutes.

[greguw]

Truck has the tell tail sign of the 80's early 90's paint de-lam pealing paint ... saves time stripping the panels and the primer is in great condition ...All the blue paint has to come off but the silver seems to have been stripped at one time . I was planing on cutting in the front door edges and new fenders ... its pretty crappy weather today plus a night out at the pub last night did not help either ...LOL
So got the doors all stripped today and started to make some pattern up the extension for the rear bumper plus the hitch . I have to extend the diamond plate down ... have to keep the local cops happy .

[Dieselwrencher]

Very nice.

[greguw]

Its starting to look like a suburban again ... front end is back on , intercooler is back in place . Going to install the ac condenser and radiator if my fan comes in today .
I'm not a big fan ... no punn intended ... of mounting the fans direct to the radiator but do to the space I will be using some little foam pieces and the zip thru fan straps . I am still working on my intercooler tube configuration ... I am trying to track down a bead roller .
I have a buddy with a metal shop and have to see if he has those dies so I can roll the ends on my tubes .
Lots to do here ... atleast I'm getting to the point that all the big purchase parts are just about done ...

[Hoods69BadBowTie]

Wow I just read the entire thread and I am speechless lol. First of all that's going to be on bad ass truck no joke Great job on the build keep up the hard work looks good. Can't wait to see it turning them big ole tires haha!

[greguw]

Thank Bro ... Just got fans and radiator / condenser in , all the radiator hoses are adapted to the cummins ... seems pretty good with a new hoses , may add a coolant filter if I have the room . Still waiting for some silicone charge tubes and a few pieces of pipe ... managed to track down a buddy with a bead roller if I need to cut the intercooler tubes down and re-bead them .

[Dieselwrencher]

Looking good! For you upper radiator hose, have you tried to find a hose bushing so you could eliminate the adapter? I've had good luck with them.

[greguw]

Thanks buddy ... I could not find a bushing that I was comfortable using ... I had a pile of them from summit but none of them had molded beads and even with a high torque clamp I did not trust the smooth bushing on a cummins .
I made up those adapters out of some aluminum fittings ... beads on both ends ... I don't mind ugly ... its a go truck and not a show truck .
Bead roller worked great ... got my intercooler all connected up . I also managed to mount up my coolant filter , just running it thru the heater core hose , a little over kill , cummins are not really known to have casting sand like the powerstrokes ... works for the big trucks so why not .
Could not track down a steel Dorman 40 gallon tank , so I opted for a plastic 31 gallon that should be fine ... Thats on its way so hope its hear by the weekend so I can get this beast running on its own .
Started to mock up the rear bumper ... made a new face plate for the ranch hand rear bumper ... its dropping it another 6" ... had to keep Johny Law happy .

[greguw]

Got the plastic tank in from MTS ... not a direct replacement as the sale guy said ... the 40 gallon cross member mount is farther back , the 31 gallon is closer so i am fabing up a new froward mount out of some aluminum stock .
Got the filler tube all hogged out for the larger diesel fill , turned out good used a 1.500 hole saw and debered the edge with a die grinder and cleaned .
Got the tank all assembled , new sending unit and converted to use for my diesel application , running a vent tube up to the front , the 90 style was a closed vent system .
Used the stock ends off the factory flex hoses , I used stainless compression fittings to stainless barbed ends .
Also with the diesel you need to run a 30R9 fuel rated hose ... not just regular fuel hose .

[68Timber]

Wow - you've got some serious ground clearance there. I know you've answered this question but I forget - how much tire/rim are you going to run?

[greguw]

The ass will come down a couple of inches once the tank and metal I'm going to add ... thats why I moved it to the other side of my shop so I can start in that area .
I have 49" Bear claws ... but the everyday tire is the Irok 42 radial .

[Corts60]

WOW! Hat's off to ya man! Super awesome build. I can't wait to see this thing done!