1991 Ford IDI engines/trucks for towing

[ognend]

I have an opportunity to get a 1991 F-350 SRW IDI truck, it is in good shape and I have some extra money to spend on fixing it up.

How are these for towing? I own a 2016 F-250 6.7L Ford and I already know that it will be night and day. However, I am the kind of person that does not fly when towing since I tow horses - when I am in that mode, I never go over 65mph- getting somewhere in a hurry is just not on my agenda, so long as I get there at some point and in one piece.

I know the old trucks are loud, the exhaust smells - but overall - can a truck like a 4x4 F-350 with an IDI engine from 1991 tow a, let's say 12,000 lbs gooseneck horse trailer that weighs 2500 or 3,000 lbs on the hitch?

I am not considering this truck for a primary tower, just a backup right now at least.

Thanks!

[FishOnOne]

Grit dog wrote:

ognend wrote:
From what I can tell, you can also put an aftermarket turbo on these. Not sure if you gain a lot from doing so, but there is that too...

Thank you everyone for sharing your experiences/knowledge. I think I am going to go and take a look/test drive.

It could be a good reliable work truck, but you keep throwing in the heavy towing duty that you want to accomplish with the truck and this isn't the truck to do that unless you like going REAL slow...especially now that you're hauling in the pseudo mountains and not board flat sea level.

If you want 1980s performance, it may be your truck. If you actually want to get somewhere, it is not.
1. I don't recall auto or manual. undocumented 30 year old auto = potential $$ and it is not a good choice for towing with an underpowered old low rpm diesel.
2. Now you're talking about pressing an OLD truck into heavy service (you don't like the 6.7 issues, want some old iron to replace it with etc etc)
3. You mention learning how to turn a wrench with this truck. Great idea and goal. Not a great idea to learn on the side of the highway pulling a grade with your horses in the Blueridge mtns.

If you actually want a capable/reliable, simple tow pig and are set on going backwards 20-30 years in technology to circumvent the "issues" with new trucks (why folks always think the grass used to be greener is beyond me, but, whatever floats your boat), then find you a 2nd Gen Dodge. 12V or 24V manual trans. Pay a few bucks extra to get a nice one with decent miles and well maintained.
Then it's an easy job to get 21st century power and relatively good drive train (NV4500 or NV5600) in a simple, easy to understand and repair type of truck.

Or step up to a mid 90s Power stroke, manual trans. Same deal and they will fetch a premium for the same reasons as the Dodge.
Any pre turbo Corn-binders (Ford/IH) or 6.5 Detroits (GM) are not worth it for real work duty.

JMO

LOL... Says the guy who recently purchased a 1980's Chevy truck.

JMO... JK

[Grit_dog]

Groover wrote:
I had a 1991 with the 7.5 gasser. As I recall the diesel was only rated for 14,000lbs GCWR. Since the truck that you are talking about weighs over 6,000lbs its trailer tow rating is less than 8,000lbs. Having said that, I have seen people pull much much more than that and get away with it. The other other question is How much do you want to pull up a hill with only 150hp? I remember driving a friends F350 1992 diesel and it didn't have much get up and go without a trailer.

Yeah, you hook 12klbs to it and try to pull a hill, you may need to chalk the tires or paint some lines across the road to actually see it moving!

[Groover]

I had a 1991 with the 7.5 gasser. As I recall the diesel was only rated for 14,000lbs GCWR. Since the truck that you are talking about weighs over 6,000lbs its trailer tow rating is less than 8,000lbs. Having said that, I have seen people pull much much more than that and get away with it. The other other question is How much do you want to pull up a hill with only 150hp? I remember driving a friends F350 1992 diesel and it didn't have much get up and go without a trailer.

[Grit_dog]

valhalla360 wrote:


At that point, would you be better off getting something significantly newer. The only complication being are you dead set on Ford, I would be a little hesitant of the 6.0 but really a 15yr old 6.0 has likely been bullet proofed or never exhibited the problems. The incurable ones are likely in a junk yard by now.

But the OP has stated he doesn't want the complication of high pressure injection motors.
Good suggestion and I'd run a bulletproofed 6.0 all day, but it would have to come at a serious discount to a Cummins or Duramax of same era.

[Grit_dog]

ognend wrote:
From what I can tell, you can also put an aftermarket turbo on these. Not sure if you gain a lot from doing so, but there is that too...

Thank you everyone for sharing your experiences/knowledge. I think I am going to go and take a look/test drive.

It could be a good reliable work truck, but you keep throwing in the heavy towing duty that you want to accomplish with the truck and this isn't the truck to do that unless you like going REAL slow...especially now that you're hauling in the pseudo mountains and not board flat sea level.

If you want 1980s performance, it may be your truck. If you actually want to get somewhere, it is not.
1. I don't recall auto or manual. undocumented 30 year old auto = potential $$ and it is not a good choice for towing with an underpowered old low rpm diesel.
2. Now you're talking about pressing an OLD truck into heavy service (you don't like the 6.7 issues, want some old iron to replace it with etc etc)
3. You mention learning how to turn a wrench with this truck. Great idea and goal. Not a great idea to learn on the side of the highway pulling a grade with your horses in the Blueridge mtns.

If you actually want a capable/reliable, simple tow pig and are set on going backwards 20-30 years in technology to circumvent the "issues" with new trucks (why folks always think the grass used to be greener is beyond me, but, whatever floats your boat), then find you a 2nd Gen Dodge. 12V or 24V manual trans. Pay a few bucks extra to get a nice one with decent miles and well maintained.
Then it's an easy job to get 21st century power and relatively good drive train (NV4500 or NV5600) in a simple, easy to understand and repair type of truck.

Or step up to a mid 90s Power stroke, manual trans. Same deal and they will fetch a premium for the same reasons as the Dodge.
Any pre turbo Corn-binders (Ford/IH) or 6.5 Detroits (GM) are not worth it for real work duty.

JMO

[valhalla360]

ognend wrote:
From what I can tell, you can also put an aftermarket turbo on these. Not sure if you gain a lot from doing so, but there is that too...

Thank you everyone for sharing your experiences/knowledge. I think I am going to go and take a look/test drive.

It's more a question of does it make sense financially.

At that age in good condition, I would be looking at under $5k to buy...are you really going to dump another few thousand into upgrading it after market? DIY you might be able to make sense but paying a shop to do (and do it right) could be more than the truck cost.

At that point, would you be better off getting something significantly newer. The only complication being are you dead set on Ford, I would be a little hesitant of the 6.0 but really a 15yr old 6.0 has likely been bullet proofed or never exhibited the problems. The incurable ones are likely in a junk yard by now.

[blt2ski]

ognend wrote:
From what I can tell, you can also put an aftermarket turbo on these. Not sure if you gain a lot from doing so, but there is that too...

Thank you everyone for sharing your experiences/knowledge. I think I am going to go and take a look/test drive.

As I said earlier, fish also I'd staying, don't out a turbo on it unless you go thru the engine and make it new! IT WAS NOT DESIGNED for a turbo!!!! I may do it to mine someday. IF and when I can plan on a new motor while it. Doubt my 30yr old motor would like a turbo!

Marty

[FishOnOne]

ognend wrote:
From what I can tell, you can also put an aftermarket turbo on these. Not sure if you gain a lot from doing so, but there is that too...

Thank you everyone for sharing your experiences/knowledge. I think I am going to go and take a look/test drive.

I wouldn't recommend putting a turbo on one these trucks unless your prepared to deal with the head gaskets either proactively or reactively.

[ognend]

From what I can tell, you can also put an aftermarket turbo on these. Not sure if you gain a lot from doing so, but there is that too...

Thank you everyone for sharing your experiences/knowledge. I think I am going to go and take a look/test drive.

[Green_Goblin]

From my knowledge you have picked a great choice. Yes diesel smells but you want these mid 90's diesel trucks. There is a difference between the 91 and the 97 AFAIK, but you don't want any modern diesel because of the emission controls are terrible. I just bought a 2008 F250 superduty gasser, its a bit underpowered (but I have not put my 2000# camper on it yet to really see what it will do) but the weight hauling/towing capacity when it comes to suspension should be able to handle anything I throw at it.

I think you made the right choice. A dually would be able to take weight better but will be harder to drive, especially in bad weather. You should be happy with your single axle.

I hope this helps

[valhalla360]

ognend wrote:
I have an opportunity to get a 1991 F-350 SRW IDI truck, it is in good shape and I have some extra money to spend on fixing it up.

How are these for towing? I own a 2016 F-250 6.7L Ford and I already know that it will be night and day. However, I am the kind of person that does not fly when towing since I tow horses - when I am in that mode, I never go over 65mph- getting somewhere in a hurry is just not on my agenda, so long as I get there at some point and in one piece.

I know the old trucks are loud, the exhaust smells - but overall - can a truck like a 4x4 F-350 with an IDI engine from 1991 tow a, let's say 12,000 lbs gooseneck horse trailer that weighs 2500 or 3,000 lbs on the hitch?

I am not considering this truck for a primary tower, just a backup right now at least.

Thanks!

We had a 1992 F250 7.3. It had it's good and bad points.

Good:
- Awesome fuel economy 20-22empty and 12.8mpg towing a 9k 5er.
- Started easy in cold weather (even at 250k miles)
- Sold it at 265k miles and the couple were immediately headed cross country.

Bad:
- You aren't going to win any drag races.
- With no turbo, in the mountains it will get you up the hill but not very fast.
- With no exhaust brake, you get almost no engine braking.
- It has a really narrow power band (1600-1800rpm) outside that it really struggled.

If I recall correctly, at 9k we were at the official tow limits of the truck. 12k would be a big jump from there.

Flat land it's a good option if you get it at a good price (it is a 30yr old truck). Mountains, I would want a later model that at least has a turbo if not an exhaust brake.

[mkirsch]

If the truck is structurally sound and mechanically sound, then there is absolutely no reason it can't do what you're asking.

It's a whole other ball of wax if the frame is rotten from rust, or if the engine is tired and the suspension is all wallowed out. If you think the truck is in good shape, though, then it's capable. All you can do is try it out and if it falls on a pile, it falls on a pile. Then you simply didn't do your homework and ended up buying a heap. Has nothing to do with the capability of the truck as designed.

The only thing that can be said about it is, it won't be anything like your 6.7PSD, but you already knew that. There really is nothing else to be said.

[blt2ski]

First off, I've found STEEP 25+% grades here in Seattle at basically sea level. Freeways ie interstates are legally per federal law limited to 6%,with short stretches to 8%.
It has as I noted half or less of the HP/torque of a 2915 or so any brand diesel. This motor was a farm truck staple, school bus for many years doing things at speeds to 40-60 mph.yes it will pull up to mid 20,000 gvw/gcw pretty well in my truck to around 50-55. It can do 60 on a level, in my case that is about 134-150hp from doing some figuring. I also have a computer print out from a dealer showing that to ba about maxed out. Most motors averaged about 100,000 miles doing the kind of work it did. A friend of mine doing lawn spray apps, would rebuild at 5000hrs, or 40'ish thousand miles. He did a lot of idling running pumps. He went by hrs more than miles.
I have around 150k.had heads redone. No other major work yet.....
If it leaks around injectors. A $5 o ring kit will solve that. Put new typical fuel rubber hose and close at the same time. $25 maybe total. I did a few weeks ago. My first time personally doing. Very sole. While at it, change glow plugs. As two need fuel line loosened and remove.
Glow plugs box and wires are semi known issues too. Easy to do.
As are injectors. If you've wrenched gas motors from that time frame, or pre 72 emissions motors. About that open and simple
Power wise. Because of the high compression, off the line I've heard a few say it's better powered initially than t444. Once turbo spools up no comparison.
You will probably find yourself in 4lo a lot pulling off road, I do well with just a red. But I have a 45-1 overall low in first gear. Most pickups even with the typical 4spd auto at that time are around 25-1, auto mid teens to one. Hence why I choose the 7spd vs 5 or 6 so manual, or 4 sp direct drive Allison. All trans options were direct drive in the IHC models.
Marty

[ognend]

blt2ski wrote:
Have that motor in my 92 IHC dump flatbed.

Hopefully it has the manual vs auto. You need ALL the gears and gearing you can get. IIRC, it was in the 180'ish/380'Ish range for HP and torque. Max for IHC built trucks is 175/335 which I have. There was also a 125 and 150 or there about version too. Made initially for school bus's. This and the 6.9 were what was initially used when IHC went to ALL diesel motors and shut down the gas offerings. Both the 6.9 and 7.3 had gas versions. Lots of power or so I've een told, but broke cranks a lot. IIRC they were known as MV404 and 445.
I have a 7spd manual, with a 10.08-1 LOW first gear, add in 4.33's in the rear with a 31" tire, it moves a lot, not fast, or can pull 40K lbs up an 18% grade barely. lower the weight it can pull steeper grades yet. Being as you appear to be in FLorida, not sure you have the steep local grade hills some of us have in other states.
If you decide to turbo it, get the specs from the T444E/7.3 PSD motors, rebuild the block accordingly, or put a t444e block in the place of the idi block. use the same turbo, inner cooler etc. Lower the compression from around 22-1 to 18-1. This motor despite MANY putting turbos on it, NEVER was intended or designed to have a turbo. If the motor is original, definitely, rebuild before adding a turbo!
The F350 from that time is better than the 250. The 250 uses a twin traction beam front end, the 350 a typical solid axel. 350 can out turn the 250 too. Or the GM IFS front ends too. Hind sight, should have gotten one of those instead of my 96 6.5TD. In 96 it would have been the T444E version.....another issue.
Have fun with it!

Marty

Thanks! I am in Virginia and yes, we have some hills around here (Blue Ridge mountains). Not Colorado, however (thank God 😉 ).

What I am reading in your post is that it will do the job, just will be slow. I don't mind slow. I have a 6.7L Ford to go fast 😉 and this IDI truck would be more for farm work - hauling as many hay bales as I can put on a gooseneck trailer and maybe hauling horses as well. To be honest, I have had quite a few issues with the 6.7L and am a bit sick of it and all its finickiness (if that's a word). I can afford to "trade up" to a 2021 gasser (like the new 7.3 Ford or the 6.6 Chevy) or even to a new diesel like any of the three, and I would not even have to borrow money to do that but I have lost faith in the "new stuff" a little. I could go back to a pre-DEF/emissions truck like the 2006 Duramax I owned but difficult to find one that was not beat up and not pay a fortune in the process as well and you still get a somewhat complicated engine.

So, I am looking to learn how to turn a wrench on an old and mechanical engine like the IDI that is supposedly much easier and cheaper to fix, and most importantly - to understand - as well.

[ognend]

FishOnOne wrote:
It will tow your suggested weight but not like a 6.7PSD. We had one years ago as part of our family farm/ranch of 1,400 acres. As for our trucks it got the snot beat out of it, but it just kept on running till it needed injectors and a transmission at which point we decided to sell it to another farmer.

Yeah, doesn't even compare, I understand that much :). Thanks!