I have a build thread started in the 73-79 area. https://www.ford-trucks.com/forums/1...l#post16629434

Just wondering about engine mounting angles. I've read ~5°tilt back. Where's this # come from? Is it relative to the position in the chassis or is it because of oil pickup/flow?

I see some people have offset the engine left/ right for clearance. Is the whole engine/ tranny/t case offset, or is it just the front of the motor, so it's sits slightly angled in the frame? how does this affect driveline angles?

I'm assuming mounted straight, inline with the rear axle input would be ideal. What's acceptable variances?

I'm also swapping the rear axle out for a DANA 80. I need to see if the pumpkins are in the same location. I just want to make sure all my driveline angles are good.

 

I haven't got into my cummins swap yet so this is just some hindsight mixed with a tad of common sense with a blind fold on... But!
Did you get any angles from the motor in the stock location / donor by chance? I'd suggest trying to go with exactly how it was intended. Although I've swapped a many motors into vehicles that was never produced and have ended out with some engine tilt, I would recommend as flat and straight as you can possibly get it. You got to keep in mind the oil is going to want to go to the rear of the motor naturally, so the less tilt the better.
Driveline angles will work up to a certain angle (depending on u-joint size) but the straighter the better there as well for u-joint wear. A u-joint that doesn't move, rarely needs replaced. Where as one with a 30 degree angle is every other year.

Good luck and looking forward to watching! I plan on using the common highboy frame that's down to a science now. The 78/79 F250 frame is a tad narrower / tighter. So not so much of a science yet.

 

That's the plan, measure and mark the position of the stock powertrain in the chassis for reference and try to get as close to that as possible, lower or further back would be a plus.

I'm mainly wondering what u joint angles are like in trucks where they installed motors offset from the stock centerline. A driveshaft lined up with the rear axle really only travels in a up and down axis, with slight side to side from axle movement, which the u joints can compensate for. Offsetting the motor is going to permanently set a second axis of motion on the driveshaft. I don't belive single ujoints are designed to handle 2 axis motion, only cv's, double cardons,etc. I might be totally wrong, it's been a long time since I actually had to worry about driveline angles.

 

Just put it in as level side to side and front to rear as possible. Make sure you have the axle you want to use in the truck before installing the engine.

I put a 12v in my 96 this summer and the engine and rear diff. is off center. Most of the Dana 80's I saw are pinion centered.

I used electric cooling fan mounted on the front side of the radiator and moved my engine as far forward as possible. I have alot of room at the back of no. 6 valve cover, and didn't have to do any body work to make clearance.

 

I think you've got the degree range right. Mine came out to about 3-4 degrees.

My driveline isn't straight front-to-back. I'm using a 2 piece driveline. I drove it around for a few months with a slight vibration when I took off from a start. But I ended up lowering my carrier bearing and now it doesn't have that vibration.

Ryan

 

When I did my 04 F-450 the mounting kit had the engine setting at 5 degrees with the fan above the radiator, they listed a custom shroud for the fan but I didn't like the way things looks.
We took the mounts off and lowered the engine until the fan was centered in the factory shroud, this had the engine at 2 1/2 degrees and we modified the mounting brackets to get the engine setting at that angle.
This did get the oil pan with in a 1/2" of the cross member and required some notching of the cross member for AC compressor clearance.
With the trans mounts inline with the original holes and the fan centered in the shroud the engine is offset to the passengers side a little, but most Ford engines are, the offset is made into the cross member.
15k miles so far and no drive line vibrations.
I'd rather shim the rear axle to correct the ujoint phase angle than have the engine all jacked up or slammed down not lining up with anything under the hood.
When most guys look under the hood of my truck they ask if the 5.9 Cummins came in the truck. That was my goal when we started the conversion

 

 

5 degrees is about right for tilt. It is just a practice that the car companies have used. It reduces the angles needed in the drive train to the back wheels which helps with vibrations.

I have done a Cummins swap as well in my 79 F250.

Even from the factory most engines are off center to the passenger side. Not sure why , but I know I put my Cummins off center that way as well. That is not just the front of the engine, but the entire engine and transmission that is to the passenger side but also parallel to the frame centerline.

 

I know the engine it's self can be installed level. I worked on offroad equipment that had these engines in them and they were all sitting in there level.

The reason they have such a deep sump in the oil pan is for when they are driven on the sides of hills so they keep oil on the pickup.