1991 f350 crew cab project.

[siegler]

I have been running and upgrading my 1990 f250 (see sig) for about 7 years now. Unfortunately the single cab leaves something to be desired when it comes to having a family....... So I bought a crew cab f350 for $1200, it's in good condition, except that it has a siezed 7.5l Gasser in it.

Figured it would be a good candidate for receiving my f250's heart. And I though this would be a good place to post my project and ask for help.

Here is the plan:
1.Tear apart the front end of the f350 to remove the engine and transmission as one unit.
Everything in the engine bay will likely have to go, looks way too different from the diesel engine bay.
2. Tear apart the f250 front end in a similar fashion.
3. Add type4's cam and an ats 088 turbo while the engine is out.
4. Put engine into the f350 with a zf5 instead of my t19.
5. Put the diesel instrument cluster into the f350 and add a piller gauge pod while I'm at it.
6. Swap my locker over to the f350.

Before starting I decided to do a compression test and crank case pressure test on the engine to make sure I didn't need to do more work on it while it's out.
Compression looked pretty good.
1: 420
2: 440
3: 450
4: 470
5: 450
6: 440
7: 455
8: 440

Crank case pressure was 5 inches of water column at 3300rpm using a home made tester. Navistar's spec is 6 inches of water column at rated rpm (3300 rpm in my case.) I was hoping for a better result, but I can't complain about being in spec I guess.

Any other tests I should do? Or do my current results mean I should have a trouble free engine for years?
Is there anything else I should consider doing while both trucks are in pieces?

Thanks for reading my long winded post!

 

[cpdenton]

It would probably be easier to consider swapping all the wiring harness out of your diesel truck into the new truck. Since they are both brick noses, it should go right in. Your manual pedals as well as gauges will swap over too.

Several,folks here have swapped a diesel into a gasser body. With both trucks there, it should be pretty simple. Good luck!

 

[IDIoit]

i dont know about your states inspection laws, but in california, i do what it takes to get around them!
diesels you dont have to smog 96 and older.

the crew cab is equipped with a computer, the F250, not so much.
i would use the wiring from the F250 into the F350.
ive used gasser trucks for parts before, and there are alot of differences.

fuel system in the F350 needs to be gutted and modified.
the tanks can be used with the F250 wiring and plumbing
you will need to modify the senders by deleting all 3 fuel pumps
(both in tank, and one on frame rail) and extending the pick ups with showerheads.
you cannot use the gasser fuel switch valve, will need to use the diesel FSV.


regarding compression test.
this method is ok for telling you how much compression you build, but it does not really tell you if there is a problem on the horizon
i dont do compression tests, pretty much.. ever.
i do leak down tests.
by filling a cylinder with air, with the piston at BDC, and the valves closed, i can actually see how well the rings and valves seal.
this will also show if your head gaskets are starting to have an issue.

IMO this is a pretty big project.

i just did a family pavement princess.
4 kids to haul around needs special attention.
http://www.oilburners.net/forums/sh...Cab-w-6-doors&highlight=8+Crew+Cab+w/+6+doors

 

[OLDBULL8]

Crank case pressure was 5 inches of water column at 3300rpm using a home made tester. Navistar's spec is 6 inches of water column at rated rpm (3300 rpm in my case.) I was hoping for a better result, but I can't complain about being in spec I guess.

Five inches of water column is good, 11 Hg is only .5 PSI.

 

[siegler]

i dont know about your states inspection laws, but in california, i do what it takes to get around them!
diesels you dont have to smog 96 and older.

Only inspection in Washington state is emissions testing every other year, and vehicles over 25 years old are exempt. My 1990 had its last test least year. The 1991's last test would have been this year, but I have tags and a registration good until 2016. So I don't think I will have to worry about it. If it becomes a problem I simply reclassify the gasser as a diesel so I can take the emissions test.

the crew cab is equipped with a computer, the F250, not so much.
i would use the wiring from the F250 into the F350.
ive used gasser trucks for parts before, and there are alot of differences.

The 1990 used to have an e4od and a computer before I swapped in the t19. I pulled the computer out with no ill effects. 1990 and 1991 share the same wiring diagram, so portions may line up. I haven't studied the diagrams closely enough to see what parts line up on the gas and diesel, the whole engine bay harness will be different at the very least, probably the dash too. Chassis wiring (brake lights and such) is likely the same at least.

regarding compression test.
this method is ok for telling you how much compression you build, but it does not really tell you if there is a problem on the horizon
i dont do compression tests, pretty much.. ever.
i do leak down tests.
by filling a cylinder with air, with the piston at BDC, and the valves closed, i can actually see how well the rings and valves seal.
this will also show if your head gaskets are starting to have an issue.

I can do that while the engine out and the valve train torn apart so the valves are all closed. Will a standard tester for gassers work? What result would cause worry?

 

[IDIoit]

any leak down tester will do as long as you can hook the gauge up to the cylinder.
excessive leakage is what it will tell you if there are any present.
listen for air escaping through crank case, intake, and exhaust. its a good idea to do this when the engine is near operating temperature.



the chassis harness is completely different as your gasser does not have the correct fuel switch valve.

i swapped a PSD into a 89 F350 460/aode so ive torn into it pretty hard and replaced the entire harness with a PSD harness...
underneath the PSD isnt so much different than an IDI besides the lift pump.

im also very intimate with my 87 F350 CC wiring as i deleted the forward tank and redid the wiring.

 

[siegler]

Haven't been getting much done on the truck lately, hopefully this week I can make some head way on tearing apart the crew cab.
I did take one of the PTO covers off the zf5 I got from the wrecking yard to have a look though.

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Doesn't look like atf to me. Maybe the previous owner of the truck I pulled it off of filled it with gear oil to cut down on noise from the single mass flywheel.
Looks like there is silt on the bottom of the case. Synchro material perhaps?

 

[riotwarrior]

No 1 ?

Does it smell like gearlube? If not...good chance just a 50w engine oil or Synchromesh trans fluid...

Not sure on goo ...

Sounds like a great project...how far are you from 98844 Oroville WA?

Oroville is about a 30 minute drive for me.

 

[siegler]

Good call on the smell, it sure doesn't smell like gear oil. Smells more like motor oil, maybe mtf, but I think it's motor oil. Is that cause for concern?

Oroville is about 5 hours away from me.

 

[riotwarrior]

K better to maybe determine whats in it than what it is...send a sample to blackstone labs tell em whatnit was in should be able to determine what gunk is.

ATF is the usual fill but as I said 50w engine oil iirc has been used. Try Pwrsmoke hes in the knkw about lubes.

As an Amsoil guy thats my preferred lube but eh...there are other options

 

[siegler]

Tore apart the front of the f350 yesterday:

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Also opened up the zf5:

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Doesn't look bad to me? I haven't looked at very many synchronizers though. Bearings looked good. Gears looked good other than the reverse idler.
Magnet was missing....and there was no gasket maker on the case halves.

 

[siegler]

Just measured the synchronizer gaps for 3rd gear and 4th gear. They are less than zf's specification of .6mm. I guess a rebuild will be in order before I use it.

 

[siegler]

Been a while since I posted progress, haven't had much time lately.
Got the gas engine and transmission out of the crew cab. I have also gutted the entire fuel system (can I reuse the fuel tanks? they are metal, as opposed to my regular cab's plastic tanks) and almost everything from the engine bay. I started doing a reverse shackle kit as well, the 35's were a bit close to the front bumper for my liking. I'm going to replaced the factory spring bushings with poly bushings while it's apart.

I got the 7.3 IDI out of my regular cab and put on the rebuild stand. I'm thinking to pull it all the way apart and measure everything. I just want to know, rather than do minimal work and be worried I missed that needed something that needed replacing.

The ZF5 has been torn down, and is now going back together with fresh synchronizers and bearings.

Soon I should be able to start transferring all the diesel related stuff from the regular cab to the crew cab.

crew cab now:

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460 with E4OD:

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7.3 IDI on the stand:

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regular cab. Minus the IDI:

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[riotwarrior]

No worky pucs

 

[siegler]

Edited the post. Do they work now?