Need Help: IDI vs IDIT

[pescadolips]

I own a 91 E350 4x4 with a 7.3 IDI. The original engine was pretty tired as it suffered as a forest service van in a previous life. I ordered a reman engine from Promar and had it installed last summer - along with a new IP, injectors, glow plugs etc. The IP has been troublesome (lack of power) and a couple of days ago I took the vehicle to a local diesel specialist. He stated that the new engine is an IDIT (turbo) version with less compression and power than the original non-turbo. So my question is, since I don't have a turbo, what are my specs? I've searched everywhere on line and can't find any stats that compare the two engines in terms of horsepower and torque. If anyone can give me some info on this, it would be greatly appreciated.

 

[bikepilot]

I'm virtually certain that the turbo IDI motors have the same compression, cam specs and all that as the N/A. They do have stronger pistons, larger pins and stuff like that so they can take more stress and higher egt without dieing. Running an IDI turbo long block as a N/A motor shouldn't result in any less power than running the N/A long block.

The Turbo injectors and IP are designed to squirt in more fuel than the N/A ones and I'd think you might get a bit of smoke and possibly excessive EGTs on a N/A truck.

Its possible I suppose that its running aftermarket high performance pistons which would be lower compression and would hurt performance on a N/A truck, but seems unlikely.

For the IP trouble, I'd make sure its getting good clean, air-free fuel (make sure lift pump is good, retun lines and caps aren't leaking, filter is fresh) then get it timed correctly and it should work fine. If it smokes when you go full throttle turn it down a little or just be judicious with your use of the go-pedal.

In terms of HP/Tq I think the turbo was rated for only a few more hp as its pretty choked up and doesn't rev out very well. It does make that hp over a wider range and when driving the two it feels like its quite a bit stronger to me - don't know if the specs were pessimistic or if its just a breadth of power curve thing. IIRC the turbo is rated at something like 190hp and 380 or 400ft/lbs. Its power comes in at less rpm than the N/A I think.

 

[towcat]

i posted in your other post.
time for you to find a diesel specialist who knows something about these IDI motors. there is no difference in compression between the turbo and non-turbo motors.
there are structural differences in the parts where you should not interchange the parts but that's all.

 

[iverger]

I'd go to the horses mouth. They should be able to tell you exactly what you have.

http://www.promarengine.com/

 

[pescadolips]

Thanks for the input. Regarding the rest of the system, yeah I've already replaced pretty much all the fuel lines, converted to an electric fuel pump, replaced orings in the filter header and the lines to the IP, switched to Raycor filters - including adding one at the tank.......But when it comes to IP diagnostics, I'm out of my depth. I didn't want to contact Promar unless I actually could come up with different specs for IDI vs IDIT as they've been great to deal with in every respect. The engine showed up well packed, super clean, fired right up, and got shipped fast. So far it sounds like it's a non-issue, but if anyone else wants to chip in or has some specs I'd appreciate it.

 

[icanfixall]

What a bunch of crap your "specialest" is feeding you. You can't see nor measure any differances in these motors. Lets start with the crank... All the idi cranks are the same... Even the part numbers are the same.... Thats 6.9..7.3 & 7.3 turbo.... All the 6.9 and 7.3 none turbo rods are the same.... Even the part numbers... The turbo rods have a larger pin diameter at 33mm compared to 28.. All the cams are the same too. All the blocks have 4 bolt mains. All the intakes are the same. A turbo pump is calibrated differantly. It has a higher pressure on the injectors... The turbo injectors "G" codes are not very good for power nor mileage but they cut down on the polution so don't use them... Use a new set of BB code injectors. There is a differance in headsfor the 6.9 and 7.3... The turbo heads have a better exhaust vlave. Its made from inconel material. It will handle the heat better but... I ran my non turbo 89 rig for 200,000 miles with a Banks sidewinder turbo boosting to 13 lbs and never had an issue. The turbo blocks serial numbers start at 1,116,331 and have all 1/4 inch oil ports but the 6.9 and non turbo 7.3 have 1/8 inch oil ports. Not a big deal. We can get anything we want that will screw into either size ports. They all have the same compression ratio but... The very early 6.9 motors had a slightly lower ratio. No big deal but I felt it should be noted. The turbo heads can be used on non turbo motors and vise versa.... There has been some talk about differant flywheels and crank balancers but if you build a motor it needs to be balanced. So thats just being posted here so others wont come along and add something that isn't exactlly correct. Now the bottom line... Nobody can just look at a motor and tell you its a turbo motor unless they have exray vision. Reading a serial number only tells you its a turbo block.... So what.. Now tell me its a true turbo motor internalyy.... It can't be done unless its being taken apart. I'll bet you Promar rebuilt a turbo block to non turbo standards. Theres nothing wrong with that either but... For someone to tell you its the wrong motor for your rig..... I call .... Promar does good rebuilds too.

 

[pescadolips]

What a bunch of crap your "specialest" is feeding you. You can't see nor measure any differances in these motors. Lets start with the crank... All the idi cranks are the same... Even the part numbers are the same.... Thats 6.9..7.3 & 7.3 turbo.... All the 6.9 and 7.3 none turbo rods are the same.... Even the part numbers... The turbo rods have a larger pin diameter at 33mm compared to 28.. All the cams are the same too. All the blocks have 4 bolt mains. All the intakes are the same. A turbo pump is calibrated differantly. It has a higher pressure on the injectors... The turbo injectors "G" codes are not very good for power nor mileage but they cut down on the polution so don't use them... Use a new set of BB code injectors. There is a differance in headsfor the 6.9 and 7.3... The turbo heads have a better exhaust vlave. Its made from inconel material. It will handle the heat better but... I ran my non turbo 89 rig for 200,000 miles with a Banks sidewinder turbo boosting to 13 lbs and never had an issue. The turbo blocks serial numbers start at 1,116,331 and have all 1/4 inch oil ports but the 6.9 and non turbo 7.3 have 1/8 inch oil ports. Not a big deal. We can get anything we want that will screw into either size ports. They all have the same compression ratio but... The very early 6.9 motors had a slightly lower ratio. No big deal but I felt it should be noted. The turbo heads can be used on non turbo motors and vise versa.... There has been some talk about differant flywheels and crank balancers but if you build a motor it needs to be balanced. So thats just being posted here so others wont come along and add something that isn't exactlly correct. Now the bottom line... Nobody can just look at a motor and tell you its a turbo motor unless they have exray vision. Reading a serial number only tells you its a turbo block.... So what.. Now tell me its a true turbo motor internalyy.... It can't be done unless its being taken apart. I'll bet you Promar rebuilt a turbo block to non turbo standards. Theres nothing wrong with that either but... For someone to tell you its the wrong motor for your rig..... I call .... Promar does good rebuilds too.

Icanfixall - thanks for the input. That is the information I was after, and I really appreciate your going to the trouble to lay it out there. I chose Promar because of their reputation - and being in the trades myself, I take that sort of thing pretty seriously. When this kind of conflict comes up, my approach has always been to learn as much as I can before I make any kind of decision or judgement. I ran out of options searching the internet and so trying to get to the bottom of it on my own had reached its limits. Cheers.

 

[icanfixall]

A turbo motor can't have less horsepower than a non turbo motor. Even Banks advertisement says they add around 164 hp to the non turbo motors... They really don't add that much... Just a sales pitch. The factory differance in turbo and non turbo was very small. I think it was around 10 hp less than the psd motors and around 10 hp more than a na motor. Now if you replaced the turbo housing and the smashed flat turbo down pipe you got lots of hp gain. Then use BB injectors... Then a 4 inch straight pipe exhaust without a muffler.... Now your adding up the hp.... You having a turbo block but no turbo means nothing as far as hp goes. What you actually have is a non turbo 7/3 motor... Nothing wrong with that... Just run the legs off it and enjoy.... Add a turbo down the line and then you really can enjoy the ride...

 

[oldmisterbill]

And in the begining all IDIi's were created equal !

 

[Agnem]

A turbo pump is calibrated differantly. It has a higher pressure on the injectors....

Rumor control here.... just to clarify, yes they are calibrated differently, but there are no changes to the internal parts. Just the fuel screw setting. All IP's inject fuel with the same amount of force, accounting for wear.

 

[Agnem]

I own a 91 E350 4x4 with a 7.3 IDI. The original engine was pretty tired as it suffered as a forest service van in a previous life. I ordered a reman engine from Promar and had it installed last summer - along with a new IP, injectors, glow plugs etc. The IP has been troublesome (lack of power) and a couple of days ago I took the vehicle to a local diesel specialist. He stated that the new engine is an IDIT (turbo) version with less compression and power than the original non-turbo. So my question is, since I don't have a turbo, what are my specs? I've searched everywhere on line and can't find any stats that compare the two engines in terms of horsepower and torque. If anyone can give me some info on this, it would be greatly appreciated.

If I had to bet money on it, I'd say the biggest issue you have, is that your pump has not been timed properly. Neither Promar, nor your installing dealer had the necessary tools and knowledge to do it.