Build Thread:: 1979 f150 7.3 IDI Conversion (Old Ironsides)

[laserjock]

Does your radiator have a trans cooler loop in it? Might be able to thread your sensor into it if it does. Not sure how it would read. Don't know if you would have to fill the loop with oil or if the air would conduct heat to the probe well enough. With the probe in the head, it will pretty much run all the time once it's up to operating temp. Did you do the 3G alternator upgrade? Two pusher fans are going to draw a lot of juice. If they run continuously, might toast your batteries. A simple temp switch is all you need or for that matter, you've with all the fab work you've done, you could just fab a mount for the one you have.


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[laserjock]

Or maybe this.

Hayden Automotive 3653 Economy Adjustable Thermostatic Fan Control by Hayden Automotive

http://www.amazon.com/dp/B000C39C6I/ref=cm_sw_r_udp_awd_QZV8sb05J3H3G


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[Old_Ironsides]

Does your radiator have a trans cooler loop in it? Might be able to thread your sensor into it if it does. Not sure how it would read. Don't know if you would have to fill the loop with oil or if the air would conduct heat to the probe well enough. With the probe in the head, it will pretty much run all the time once it's up to operating temp. Did you do the 3G alternator upgrade? Two pusher fans are going to draw a lot of juice. If they run continuously, might toast your batteries. A simple temp switch is all you need or for that matter, you've with all the fab work you've done, you could just fab a mount for the one you have.

Or maybe this.

Hayden Automotive 3653 Economy Adjustable Thermostatic Fan Control by Hayden Automotive

http://www.amazon.com/dp/B000C39C6I/..._QZV8sb05J3H3G

I do have the oil cooler in this radiator, and I haven't done the alternator upgrade either. I like that thermostat you linked to, that price is much nicer than the 110 or whatever it was on summit for one. I think that might be the way to go. If i can avoid draining the coolant I just put in there to move the sensor that would be a plus. Something that could be fine tuned like that would be nicer as well.. I'll keep that bookmarked, thanks

 

[LCAM-01XA]

Sensor is in the head, I put it in the unused hole towards the back on the passenger side. Some arrangement up at the radiator would be more ideal but this sensor is a NPT threaded one. I should have sprung for the more expensive adjustable thermostat kit, which had a threaded sensor but also an optional radiator probe sensor... Might still have to do that

IIRC front of engine is where the coolant is hottest, so by running switch in the rear ports you could be seeing lower temps which may work out better with the switch you have. But if you want it near the radiator you can grab one of these and drop it in your upper rad hose and go from there: http://www.glowshiftdirect.com/custom-water-sender-attachment.aspx
May have to redril and retap the sensor hole tho, that 1/8" port they say it comes with is a bit on the small side, most switches I've seen are 1/4" NPT or 3/8" NPT.

As far as fans efficiency, my truck tends to maintain 190-200F measured at the factory overheat sensor location in the front of the engine, this is just running around in cool weather with e-fans off. When worked harder she will run warmer, around 210, still with e-fans off. Once the fans are on (I have manual switches) they will quickly bring the temp to under 180F. So if I were you I wouldn't necessarily worry about the lowish CFM of the fans just yet, depending on your driving there's a good chance you may not even need them. Run what you got and see how it works, then make change as needed.

Also you are right about the lower rad hose, as short as those pieces are there's no need to mess with springs inside them. What I would be concerned with in this situation is vibrations from the engine transmitting to the radiator, and also the engine pulling on the radiator during high-load conditions that tent to twist it slightly in the motor mounts - do you think those can present an issue?

 

[Old_Ironsides]

IIRC front of engine is where the coolant is hottest, so by running switch in the rear ports you could be seeing lower temps which may work out better with the switch you have. But if you want it near the radiator you can grab one of these and drop it in your upper rad hose and go from there: http://www.glowshiftdirect.com/custom-water-sender-attachment.aspx
May have to redril and retap the sensor hole tho, that 1/8" port they say it comes with is a bit on the small side, most switches I've seen are 1/4" NPT or 3/8" NPT.

As far as fans efficiency, my truck tends to maintain 190-200F measured at the factory overheat sensor location in the front of the engine, this is just running around in cool weather with e-fans off. When worked harder she will run warmer, around 210, still with e-fans off. Once the fans are on (I have manual switches) they will quickly bring the temp to under 180F. So if I were you I wouldn't necessarily worry about the lowish CFM of the fans just yet, depending on your driving there's a good chance you may not even need them. Run what you got and see how it works, then make change as needed.

Also you are right about the lower rad hose, as short as those pieces are there's no need to mess with springs inside them. What I would be concerned with in this situation is vibrations from the engine transmitting to the radiator, and also the engine pulling on the radiator during high-load conditions that tent to twist it slightly in the motor mounts - do you think those can present an issue?

That would be good if it is cooler towards the back.. would make sense too since the coolant back there would not have been through any of the head yet, where it will pick up the majority of its heat. That inline adapter looks like a good possibility too, but do you think it would still ever get cool enough in the upper hose? once the truck is up to temp seems like there would always be a little coolant still flowing past the thermostat, even if it is not all the way open. I don't know that it would ever see 185 up there. Bottom hose I'm sure is the ideal solution, given the room to do it... in reality I could weld a sensor bung into my elbow... not that I want to drain all of the coolant and take that apart again though, especially when I have no leaks going. But yea, like you said I'll just have to run it and see what happens for now, might work out fine.

On that lower hose I was a little concerned about that to start with, but once I got everything together there is still enough flex between the hose pieces that I don't see it posing a problem. I definitely would not have wanted to go any shorter on the hose pieces though.

 

[laserjock]

The reason I suggested the trans cooler bung is its not tied to the antifreeze. Wouldn't have to drain anything. Just have to stick a plug (albeit quickly) in the port on the head and then you can move it around. Bottom line is, drive it a little and determine if you have a problem before you go about fixing it.

 

[Old_Ironsides]

The reason I suggested the trans cooler bung is its not tied to the antifreeze. Wouldn't have to drain anything. Just have to stick a plug (albeit quickly) in the port on the head and then you can move it around. Bottom line is, drive it a little and determine if you have a problem before you go about fixing it.

Right, that is true.. I'll have to eyeball that and see what the size of the fitting is going into the cooler.

 

[dirtbiker]

Thanks! Yea that radiator was a bit challenging to fit in there but I am happy about how it turned out. Originally I was planning on using the '79 radiator, which probably would have worked out since it had the "super duty cooling system", but that radiator was very weathered and as I found out, had very brittle tubes. I did it in when I was taking the bumper off, and I tapped the radiator with the ratchet handle right on a tube, split it open, and got a bath. It probably is better that I did not take that route anyway since if I hadn't done that, it probably wouldn't have been long before the radiator let go on its own, in a less convenient place.

This here was my first experience with electric fans, and they don't seem to push quite as much air as I was hoping (even though they are supposed to be 2300 CFM each, they were some of the highest CFM rated among 12 inch fans) but I think once I get some sort of shroud made to get more of the air going through the radiator they should be pretty sweet. I may have screwed myself a little with the thermal switch to activate them though, since it is a 195 on/185 off. I neglected to take into account that these engines have a 190 thermostat, so my fans may never turn off unless the switch is calibrated a little high... might be something ill have to take care of eventually, but if the fans only are going to come on a couple times during the really hot days in the summer, I can probably live with them running until I shut the truck off. If they are coming on all of the time though I'll have to do something.

I should be able to get a first drive video, I have a holder for my phone that I can suction cup to the windshield to do that with. You're right, that would be pretty difficult videotaping and diving at the same time with a standard while holding the camera

Sure thing, it's good to see what my other options are for the future (even though my radiator was new when I put it in). Gotta love a good ol coolant washing, I got mine when I was changing my block heater and forgot to drain the block

2300 should be plenty, though it may provide less cooling than a pull setup. That's okay though, I still think you'll be just fine. Once you get it running and driving, you can see how everything actually does. It may be perfectly fine, it may need adjustment. I personally have my fan on a manual switch so I can't really say one way or another, just see what it does.

Nice! I didn't even think about that, actually I don't even think I video'd my first drive because I was just too excited. I have tried to take videos while driving though and it does NOT work well with having to shift and steer lol

 

[Old_Ironsides]

hey everyone

been a while since I've checked in but here is another update.

I have finished up the truck in the past few weeks here, and I am quite happy with it. I do have some driving video for those who want to see that, and I'll upload it soon when I have a chance. I also will throw up some more pictures of it all said and done later on too. No major surprises so far with 170-180 miles on it. One thing that i do need to take care of is getting the front axle centered back up, as the truck pulls slightly when going down the road. I still have the original track bar, and did not get a drop bracket of any sort, so I have coming an adjustable track bar, since I really don't know exactly how much lift over stock the truck has now to just use a drop bracket.

Have a few minor fuel leaks to take care of too, at the fuel heater plug, and it needs to be treated to a return line kit before too long also. Neither is bad enough to cause starting issues yet, but they are noticeable, especially the leak at the fuel heater. Its also needs a CDR valve, since it is definitely pushing some oil. Wish they were easier to come across, but I'll have to stop down at my local IH dealer sometime this week and hope they know what i am taking about.

Otherwise everything seems to be working very well, and fuel economy looks promising too just by watching the fuel gauge. The next fill up will tell for sure.

 

[SHARPIE]

Nice lookin build you got going there, If the truck is bump steering the track bar won't fix that it only centers the wheels you'll need to change the C bushings to 7* negitive, you'll only need to drop the track bar if you added a drop pitmen arm, FYI the HD rad works great with the diesel set up but yours being so far fourward it may not fit and you have welding skills what I did was modify the stock booster brackets to except the 90 booster works great if you want Ill pop up some pixs.

 

[Old_Ironsides]

Nice lookin build you got going there, If the truck is bump steering the track bar won't fix that it only centers the wheels you'll need to change the C bushings to 7* negitive, you'll only need to drop the track bar if you added a drop pitmen arm, FYI the HD rad works great with the diesel set up but yours being so far fourward it may not fit and you have welding skills what I did was modify the stock booster brackets to except the 90 booster works great if you want Ill pop up some pixs.

Thank you. It doesn't have any bump steer to speak of, since I haven't put on a drop pitman arm, and the drag link and track bar are still parallel. The pull I have is when just going down the road in a straight line without braking or hitting any bumps, when the wheel is let go it want to go right a little bit. Driving it is not really noticeable when holding onto the steering wheel, since it is not a severe pull, but it is enough that it isn't going to do the tires any good wear wise. I am attributing this to the axle being off center, since the truck did not pull at all before, and this is really the only thing that has changed as the height went up. Not even toe has changed since on this the tie rod on this connects right from knuckle to knuckle. C bushings should be alright at 4 degrees, since the springs were 4 inch to start with, and with the weight over the front I would say they are definitely more in the 3 inch range. The steering returns to center quite well too, so I think they are right on. The truck also sits a little lower on one side in the front, which from my reading looks to be another symptom of an off-center axle.

The HD radiator was a consideration of mine, and honestly would have been easier, although I would have still had to use a pusher fan setup on the front with the limited clearance on the engine side. The reason I didn't take that path was because the cost to replace the HD radiator with a new one was actually going to be more that getting a new early style IDI radiator like I did. Since this was the case I decided to go with the diesel rad, even though it required a little more fabrication to get it in place.

That sounds like another good solution to the booster clearance problem, being as those are so much smaller diameter. You are more than welcome to put up some pictures if you would like, I'm sure there are others who would like to see that approach also. The more ideas on here the better, for anyone else who might take on a project like this.

 

[Old_Ironsides]

Here is some driving video I took. Its not too exciting, and my phone didn't pick up the sound all that well, but I also had the windows up. When it warms up outside I'll get some better video of driving it, but this is something at least for the time being.


http://www.youtube.com/watch?v=lSRhcOLf5G4

 

[laserjock]

Love those old trucks. Doesn't sound too obnoxious in the cab. I always wanted to go find a clean 79 and put modern running gear under it. Congrats on a nice build! Now it just needs to whistle a little.


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[trackspeeder]

Here is some driving video I took. Its not too exciting, and my phone didn't pick up the sound all that well, but I also had the windows up. When it warms up outside I'll get some better video of driving it, but this is something at least for the time being.


http://www.youtube.com/watch?v=lSRhcOLf5G4

Sounds good.

Thanks for the ride.

 

[Old_Ironsides]

Love those old trucks. Doesn't sound too obnoxious in the cab. I always wanted to go find a clean 79 and put modern running gear under it. Congrats on a nice build! Now it just needs to whistle a little.


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Thank you! It really isn't as loud as I though it might be in the cab, which I am happy with. Can still listen to the radio comfortably anyway lol.

It may develop a whistle sometime down the road