Cummins 4BT & Diesel Conversions Forums banner

1 - 20 of 135 Posts

·
Registered
Joined
·
57 Posts
Discussion Starter #1
1988 S-10 4.3L V6 4x4 5150-GCVW shortcab, shortbox, 235/75R15's.

Immediate Future:

4.3L V6 out, 4BT3.9 in. Built 700R4 with TransGo stage-3 shift-kit, remote-filter/trans-temp gauge, 11,000GWV cooler currently installed. Will retain NP231 transfer case. Dual Flex-O-Lite 12" pusher fans 2500-CFM total (in front of A/C condenser and trans-cooler) installed.

Ongoing Upgrades:

Replace the rear axle with a GM 9.5" 14-bolt with G80 locker and 3.73 gears (in the process of shortening). New leaf-springs. Replace S-10 IFS (less front-diff) with K2500 IFS. (on hand, fabricating brackets). New torsion bars. 265/75R16 wheels when the suspension is done. Guessing about 6" of lift from stock (front/rear, no stance chance), hoping for a few extra inches of wheelbase without needing huge wheel flares ;)

Goals:

20-30MPG highway, on-tap towing/4x4 power, and a lot of noise and smoke when the go-pedal meets the sheet-metal.

Ongoing project pictures soon!!!
 

·
Registered
Joined
·
500 Posts
Ditch the IFS - if you're going to pull the old stuff, might as well fix it right. Your torsion bars will thank you later when they're replaced with leafs (or coils, if you wannabe fancy :)) curious about the semi-floater 14 bolt narrowed? What bolt pattern for wheels? 6-lug FS chevy?
 

·
Registered
Joined
·
57 Posts
Discussion Starter #3
The solid front-end is an interesting idea... Is there a spring setup that could be made to work with an S10? Do you have any suggestions for a solid axle that would be good for a project like this?

As for the semi-floater, the axle-shafts are the 6-lug FS from a 1998 heavy-duty (F44?) 1500 pickup.

Suggestions are definitely appreciated at this point.
 

·
Registered
Joined
·
500 Posts
The solid front-end is an interesting idea... Is there a spring setup that could be made to work with an S10? Do you have any suggestions for a solid axle that would be good for a project like this?

As for the semi-floater, the axle-shafts are the 6-lug FS from a 1998 heavy-duty (F44?) 1500 pickup.

Suggestions are definitely appreciated at this point.
If you've got the rear already, use it, no problem if it's free. If you're paying for one of those, dont pay much - there are much more common (and stronger) setups (D60, D44, Ford 9in rear) that you can shorten IMO.

Front end? The possiblity is endless. I'm sure there's a SFA conversion kit with the correct brackets for leaf springs. They have em for all the fullsize trucks.

A good front end? For your existing T-case I'd say a Ford Bronco 44 front, which has the passenger drop you'll need (more than strong enough for a daily driver). It's a coil front end, so some spring pads (if you go leaf) will have to be added.


Link for S10 SFA swap - http://www.s10forum.com/forum/f134/solid-axle-thread-68267/
 

·
Registered
Joined
·
1,450 Posts
The Ford F150/Bronco, F250 Dana44 HP fronts are all drivers side drop diffs. At least the full size ones are, I can't speak for a bobtail Bronco or the Bornco II. GM and Dodge used the right side drop Dana44 axle housings.
 

·
Registered
Joined
·
500 Posts
The Ford F150/Bronco, F250 Dana44 HP fronts are all drivers side drop diffs. At least the full size ones are, I can't speak for a bobtail Bronco or the Bornco II. GM and Dodge used the right side drop Dana44 axle housings.
Yeah I'm thinking bassackwards today, it's been rough day at ADC. The Early Bronco 44/F150 44's from the 76(disc brakes) & up should work. I was thinking driver & said passenger :rasta:
 

·
Registered
Joined
·
57 Posts
Discussion Starter #7
Ok, thanks for all the input guys... I never would have considered an SFA conversion as being that 'simple', but from the looks of that website, it seems like something worth looking into for long-term durability. I've definitely been in the 'excessive premature front end wear' boat.... That's why i was thinking of just upgrading the IFS to the setup from a K2500. Reduced articulation aside, does the SFA ride well, or does it stiffen it up? (I've only heard bits about SFA on some 'hardcore' offroad shows like extreme 4x4... i think i'll have to do some research and see what's fact and what's myth with these things.) Also, I have the 1500# stock rear suspension on my rig, and it already rides like a dump-truck when it's empty... I guess it couldn't be any worse with a SFA. ;)

Once again, thanks a bunch, I'm finding a lot of useful tidbits on this site.
 

·
Registered
Joined
·
500 Posts
the A-arms on a 2500 will be wider and have different geometry than your S10's frame - you'll be fabbing special mounts to utilize different A-arms on your current frame. You could do any of the following:

1. Rebuild your current IFS - if you can make the swap work
2. Switch to a 2500 or bigger IFS Frame and spend tons of $$
3. Swap in a solid axle & have leftover $$$ for :beer:
 

·
Registered
Joined
·
57 Posts
Discussion Starter #9
I have thought about the new bracketing required for the geometry... but I am also liking option #3 quite a bit. :D
 

·
Registered
Joined
·
25 Posts
x2 on the SAS it will be worth especially if your doing 6in lift it will fit no problem. for the rear forget the gm 9.5 it is worthless get a 14 bolt FF 10.5 that way if you snap a shaft you can still drive home, also not sure how wide of an axle you are looking for but a c&c (cab and chassis) 14 bolt from a dump, flat bed or tow truck could be had for a couple hundred, put on disc brakes for another 100 and you got a bombproof rear end, also a detroit is like $300 for these axles, i think the WMS is about 63" not 100% on that tho. also pretty sure a Wagoneer will have a D44 that will be a good width for a S-10 with out going to full size width but that might be pass drop.?...
WYLIE
 

·
Registered
Joined
·
57 Posts
Discussion Starter #11
I've heard about the GM 10.5" FF's... From what I've read, i'd need about 5,000 ft/lbs of short-term torque and 1,500 ft/lbs continuous torque at the differential to overload a GM 9.5" SF. (assuming the tires lock up and don't spin). The 10.5" GM diffs offer (once again, from what i've read) 1,242 ft lbs more short-term torque at the 9.5" differential, but as a daily-driver with no towed load, could I expect to exceed the 9.5" capacity? No debate that the torque capacity (of the 9.5") is hugely greater than my stock S10 differential, but since I already have the 9.5", will that meet my reasonable needs?

The most i haul right now is a box-full of gravel, or a pop-up trailer with a 3200lb gross weight... What i'd like to be able to haul is a 4000-5000 GVW trailer on a Class III hitch. The only off-roading i do is when there's 6-8" of powdered snow in the passing lane on my drive home, and i've got it slammed in 4H on the x-fer case at 62mph. The only time i have it in 4L is when i have to run a huge snow-drift, and at that time of year, I 'ain't haulin' anything except my sorry-butt home in the -22F weather. ;)

From what i've calculated, the 3.42 gearing on my 235/75R15 tires is very close to 3.73 gears on the 265/75R16 setup i'm planning (MPH vs engine RPM). I haven't calculated for the added torque of the 4BT, but it can't be more than what a Duramax puts out (the stock config for a SF 9.5"), and that is supposedly adequate for a duramax given that the wheels will break loose long before you exceed the torque capacity of the axle.

Once again, i'm the newbie here... I certainly don't want to be trying something to have it fail quickly under the conditions i expect it to perform in, but given that i already have the 9.5", would it work in the capacity i'm hoping for? If i was building something with a higher rear-ratio, or a higher transfer-case ratio on >265 tires, i would definitely be worried about torque loads, and would probably have just gone with a Dana 60. ;)

Comments, Suggestions anyone? :confused:
 

·
Registered
Joined
·
1,462 Posts
The semi float 14 bolt is a fine axle. They're two huge issues are with sloppy spider gears in open diff ones and the Gov-lock and explode LS's these things came with. 14 bolt semi float axle shafts have more beef than the full floater axles, they're not going to break behind a wee 4BT. The 9.5 makes a good rear when you throw away the stock carrier and replace it with an aftermarket clutched LS.

Personally, I'd think ahead a bit more and pick your rear axle based on what matches the lug pattern on the front you go with. If you go with an EB front axle and you'd like to keep the 5 on 5.5 pattern you've got some pretty stout rear ends to choose from in that lug pattern. 1st pick would be a 56-72 Ford F-100 semi float Dana 60. These are real narrow and many have powerlock LS's. You won't break one. Next would be a 31 spline 9 inch which are everywhere.
 

·
Registered
Joined
·
57 Posts
Discussion Starter #13
Wow... I've been a member of some other diesel forums before, but I've never seen this much 'free-thought' when it comes to what other people have found out through trial and error. ;)

Based on the parts I have sitting around right now, the 6-lug GM pattern is what I'm going to stick with. Knowing now, the SFA seems like a better option, but I already have the 3/4 ton upper/lower control-arms and the spindles (less hubs) for an IFS setup. I have access to a CNC plasma cutter and CNC brake at-cost (materials), so I think at this point i might be cheaper-off going with a FS 3/4 ton IFS on the 'S-10HD' project. I do have a 1984 GMC Jimmy, that I may stuff a rebuilt GM 6.2L Diesel into as a future 'Family Car', ( read: ) that I may want to build up as the ultimate tow/haul/family diesel, so I definitely appreciate EVERYONES replies on SFA options. :)

I think I'm going to 'upgrade' to rear disc brakes on the 9.5" 14-bolt SF, using CNC plasma-cut brackets, bracket plates, and readily-available semi-loaded calipers. It would seem that the 12.75" rear-disc brakes from a 2003 GM Silverado will fit my bolt pattern, but I want to see if i can get a little more meat out of the discs (13" or better rotors, with 'stock' 2-piston calipers'), as well as finding the cheapest option.

I finally got to test-run my eBay-bought 4BT today on my home-built test-stand, and she seems to run well... From what I've read, the puff of black smoke at startup is normal (or is it?). Boy does she bounce, with no engine vibration dampeners installed. (I plan to address that. If I decide to do 'high power' engine runs, but I doubt I'll subject the motor to that kind of abuse without the fluid dampers, given It's been good to me thus far.)

The configuration I have seems to look like I have to offset my engine 10-degrees towards the passenger side, as well as orienting the motor mounts 10-degrees forward, to compensate the angle in the GM P30 brackets and adapter plate. (pending current drive-line angle measurements).

However, as described, the mounts are in the 'forward' mounting position, and I need to move them to the 'rear' position in order to obtain approximately 12" mount to bell-housing distance. (given my current 4.3L V6 setup).

I plan to use the built-700R4 currently in my S-10, with the governor out of a the diesel TH400 that I got with the engine (less the drive gear). If anyone is looking for a diesel TH400 or a reputable eBay seller (4BT), PM me, and I will be more than happy to pass along information.

The last decision I seemingly need to make, before I proceed with my 4BT installation, is to decide if the Dodge 5.9L accessory bracket (alternator & A/C compressor) is the better (cheaper) option, or if I should fabricate my own to make use of my Harrison GM A/C compressor. (so I don't have to purge and re-charge my perfectly good A/C.)

Once again, comments/personal experience is greatly appreciated!!! :)

P.S. I forgot to mention, I already have the GM Hydro-Boost hydraulic brake-booster installed. (Despite being shipped an inferior quarter-ton unit, which I plan to upgrade to match the 3/4-ton booster I have sitting on the shelf), it looks like it will be a direct bolt-on to the integrated 4BT power-steering pump, as far as the hoses go.

I have pictures of the custom hood-latch support that I had to fabricate for my electric fans, but the pictures didn't turn out, so I will post them in a later reply.
 

·
Registered
Joined
·
500 Posts
I haven't calculated for the added torque of the 4BT, but it can't be more than what a Duramax puts out (the stock config for a SF 9.5"), and that is supposedly adequate for a duramax given that the wheels will break loose long before you exceed the torque capacity of the axle.
All duramax equipped trucks (2001 and up) use an 11.5" AAM Axle, the gassers get the older 10.5" corporate. The 9.5" Semi floater has been all but phased out, only appearing in some 2500 suburbans and 1500HD trucks. I've seen Suburbans with both rear axles (9.5 SF and 10.5 FF)in the later model 2500 series. Let us know how you get the geometry correct for that IFS swap, it's going to be interesting
 

·
Administrator
Joined
·
1,447 Posts
The last decision I seemingly need to make, before I proceed with my 4BT installation, is to decide if the Dodge 5.9L accessory bracket (alternator & A/C compressor) is the better (cheaper) option, or if I should fabricate my own to make use of my Harrison GM A/C compressor. (so I don't have to purge and re-charge my perfectly good A/C.)
If you use the Dodge setup, you'll likely have to do some frame notching to clear the AC Compressor.. Normally not a big deal, but could thoroughly complicate things with your planned suspension modifications..

A lot of the Chevy conversions are using the Kenworth adapter / Dodge compressor setup that moves the compressor and alternator up, the lower water hose connector down. Makes things fit between the rails. 3930888 is the number for it at your local Cummins dealer, IIRC..

Now, re-using the existing compressor is an idea I'd like to do, but there's a complication that I don't know the answer to yet: The Chevy compressor uses a "6V" serp belt, the Cummins an "8V" serp belt. Without having to come up with another set of pulleys / tensioner, I wonder what the effects of just using a "6V" belt would be. I can see possible issues with the belt hopping around on the wider pulleys, and maybe there's a reason it's wider on the Cummins.. I have gone as far as to determine that the ID of the bearing that the compressor pulley rides on is the same between the two compressors. Whether or not you could make a Frankenstein compressor using the Chevy compressor body and clutch and the Dodge pulley / bearing is the thingn I want to know. It would sure simplify a lot of installs to be able to use that short, stubby Chevy compressor instead of the long Dodge that interferes with oil filters / turbo intakes on a lot of swaps.

So, anyone tried this yet? Or, for those folks with full Cummins parts guides, do they make a set of pulleys to run with a 6V belt instead of the 8?
 

·
Registered
Joined
·
1 Posts
Will be checking into this thread. I have recently decided to maybe try and jump into this. Looking right now at using a S10 Blazer 4x4. So hopefully i can learn some things from you.
 

·
Registered
Joined
·
127 Posts
The solid front-end is an interesting idea... Is there a spring setup that could be made to work with an S10? Do you have any suggestions for a solid axle that would be good for a project like this?

As for the semi-floater, the axle-shafts are the 6-lug FS from a 1998 heavy-duty (F44?) 1500 pickup.

Suggestions are definitely appreciated at this point.

FSJ Wagoneer widetrack Dana4 axle and leafs. fab a front crossmember a la the Stagewest 4X4 SAS swap kit they used to make, and use the existing hole in the frame under the A pillar. Sleeve it, use a 1/2" GR8 bolt, hang the shackle inboard of the frame (1/2" extra offset on the passenger side, IIRC), and make some Z brackets to reinforce the shackle bolt's inner side.

DEFINITELY ditch the IFS if you're gonna build this. I'm building an 89 as well. I am using a 5.7 diesel as it was given to me and is in good shape. If I have ANY problems out of it whatsoever, I'll go 4BT out of a bread truck.

Oh yeah-- when you get the axle out of the FSJ-- get the rear as well, if it's the centered pumpkin. It'll be D44 or AMC20. If it's the 20, it won't have the problem the CJ AMC20's did (two piece axleshafts) and it is comparable to the D44 in strength (and actually exceeds the D44 in several key areas, like pinion girdle IIRC).

Best plan: buy a FSJ with dead engine. Rip the axles, driveshafts, and springs out, and go to it.

BTW-- if you move your axle forward 2" when you do this SAS job, you can generally reuse the Wagoneer front driveshaft. You'll need a Jeep XJ (mini cherokee) pitman arm. Stay springunder and you don't have to sweat the steering much. You also don't get stupid-high if you stay springunder.
 

·
Registered
Joined
·
57 Posts
Discussion Starter #19
haha... I have to admit a bit of ignorance here... :( I just checked today (before reading the posts) and noticed exactly what you were so astute to point out, that the GM compressors use a 6-serp and the dodge/cummins an 8-serp.... That makes a direct retrofit an unlikely option, since playing with pulleys on an A/C compressor is a dicey situation, IMHO. Hopefully nothing a trip to the junkyard won't fix (for an 8-serp compressor).

When i put the GM hydro-boost on my truck, I used the pulley that came with the 6.2 diesel pump which was out of allignment with my 4.3L V6 pulleys by no more than 1/4", subsequently shredding my serp belt in under 10 seconds... So i'm leery to start experimenting with differing pulley configs... Guess my easy fix is out... Shame is i just topped up my system with some R12a... Oh well...

As far as bracketing goes, I've got a 'clean slate' for development of a bracket... (within the limitations of the belt tensioner and drive pulleys, of course...) I've run across the factory brackets (in other forums/posts) and am trying to construct a CAD file for the profile to make it easier for future conversions. The basis for my design is the 2-piece standoff (A/C & coolant-intake/idler/alternator) vs. the all-in-one plate that is found on the 12-v 5.9 cummins (1992ish) that come up on e-bay. Unless someone happens to know the P/N for the bracket i'm talking about, and it's reasonably priced, I'd rather invest my time and gain a little experience doin' it myself. ;)

Also, machining parts is expensive, so if there's a way to have a 'rough cut' a 1/4"-3/8" steel plate with some feet/spacers, i would imagine that's a much more viable (read cheap) option for other 4BT conversions.

Our heli-mechanic's 5.9 dodge has been sitting in the parking lot for the past week, so i've been taking measurements of the 'factory' brackets for a baseline... With the comments i've read here, it sounds like i might be better off putting the motor in first, and then making brackets to fit equipment after... I don't like the idea of cutting the frame too much, even though it looks inevitable with the starter motor, but who knows... if anyone knows, let me know! ;)

Has anyone experimented with different water-pump coolant intake diameters? The factory one is over 2", I want to be able to weld a nipple onto my new plate, but the largest i can find at a big-box store (Dome Hepot, wink wink) is a 1-1/4" fitting... will this flow enough coolant?

As for the full-sized K2500 IFS and 14-bolt 9.5" upgrades, those are 'phase 2' upgrades, but I will definitely post updates as to progress on those. My inspiration for the front-end upgrade came from a 6" suspension lift-kit for the S-10 that dropped the IFS and front control arms for what I was hoping was going to be a GM 6.2L conversion for my A/C equipped S-10.... (the 6.2 has been relegated to my non-A/C '84 jimmy) So i figured, with the under-vs-over spring slung axles (9.5 vs 7.5, respectively) instead of just dropping the puny front suspension (IMHO) with bolt-in brackets, I may as well use something from a heavy-duty full-size pickup, hopefully solving the lift and potential wheelbase increase required to keep the handling the same as before (with a few hundred extra pounds from the motor), but with adding a few more inches of clearance, and the capacity for a few more ponies.....

Something else I mentioned in a previous post that i've taken a good look at now is the 700R4 TV setup.... I realized that the throttle/cruise control work in a 'retraction' manner, while the TV cable works in an 'extention' manner..... That is to say (for people unfarmiliar with the system), as the go-pedal is depressed, the throttle cable retratcts, pulling the throttle 'arm' towards the firewall.... At the same time, the 700R4's TV (throttle valve) cable needs to extend the cable away from the firewall... Now, the TV cable IS adjustable, but from what i've observed, there is a minimum ammount of travel required, otherwise you risk burning clutches and all sorts of shift problems... (I'm planning on measuring the TV travel on my 4.3 to establish a baseline.) I may see a solution in a custom bracket attached to the opposite side of the VP44 throttle-arm, but it looks like I only have just over an inch of TV cable travel.... (I've smoked a 700R4 with improper settings right after a rebuild, so I'm leery about just allowing for an arbitrary ammount of TV travel....) I may end up building a 4L60E/4L80E transmission controller yet... I hate the thought of buying an 'off-the-shelf' unit for nearly a thousand bucks when I can build a 'custom' ECM/PCM/whatever-they-call-em-these-days for a fraction of the cost.

Oh, since the rear-axle is a phase-2 project (post 4BT) i'm thinking of fabricating the brackets to do a drum-brake conversion. If that is the case, I'll probably upload the CAD files to save others a butt-load of work ;)

Once again, always apreciate advice/input, and thanks.... (i'm all 'outa smilies)
 

·
Registered
Joined
·
127 Posts
just buy the tranny controller. By the time you figure out how to control the transmission properly you're money and time well ahead to just buy a box to do it.

I wouldn't even consider the IFS lift.
 
1 - 20 of 135 Posts
Top