COE Moving engine behind the cab

I have decided to move my engine to behind the cab. It is an 8.1 in the 2001 chevy 3500 cutaway frame. I would like any and all suggestions on what to do and what NOT to do. I have never done this and don't want to reinvent the wheel. Again, all suggestions welcome! Pictures would really be helpful. Dave

 

hmmmm... Is your frame fully boxed, front-to-back? If not, I'd box at least where the motor is going... Cooling... My setup works using the stock C5 dual fans, but it didn't work until I took fairly careful measures ducting the air back from the grille to the radiator which is mounted in front of the engine. I wonder if having the radiator up front might work even better....

 

Yes on the boxed frame. I did have room for both the radiator and air conditioner stuff up front behind the grill.

 

I was thinking I would keep the radiator up front. This thing has has engine cooler, oil cooler transmission cooler and power steering/ hydro boost cooler.

 

I wonder if the water pump will need some help in order to drive the coolant a further distance.

 

Good thought!

 

I had a Studebaker pick-up that I couldn't keep cool. I placed a second radiator under the box and ran coolant to both using the original water pump. I never had a problem with flow in that system! That second radiator cured the overheating

 

Will moving the engine to behind the cab affect my front end alignment, and if so how much?

 

Yes it will and quite funny you should ask... I had this discussion with my alignment guys last weekend for the CoroVette... I asked if they could do the alignment before the body was on for better access. They said it would not be set correctly without the added weight. I think it was the camber setting but don't quote me on that... These are the same guys that come highly recommended and aligned Buford for me.

 

Just one more thing to deal with.

 

All right folks, I am going to fess up. I am not totally new to this kind of work but I have never made my own engine mounts and certainly never moved an engine to behind the cab. Any and all advice is welcome at the most basic level if necessary. I have the welding skills and if necessary I have several friends with fabrication skills. Pictures are always appreciated. Dave

 

With my coe having a box rather than a pickup bed or flat bed the access to my motor will be a doghouse in the box. If the engine ever has to be removed though the frame was slightly notched (and boxed with 1/2” plate) so it can be dropped out of the bottom.

Image000000 by scott selvidge posted Oct 6, 2023 at 4:13 PM

 

I used the stock 2002 Dodge trans xmember for the engine and then fab'd a new trans xmember.

 

It was simple for me. the engine and frame donor was a mid engine fire truck and the engine (and radiator) is mounted in its original position in the frame on its original mounts. I did have to whack a couple feet off the front of the frame to match my cab.

 

What are your thoughts and suggestions? Should I try to replicate the angles and positioning of the engine and trans in the new position? As is the engine is offset toward the p***enger side, should I keep it that way? It has a 2 piece drive shaft and I will have to see if a single will work.

 

I think I should keep the weight as far forward as possible, how close to the cab should I get it? What have you folks done? Dave

 

Just some free thoughts!
I've always felt that following "Detroit engineering" as closely as possible helps keep one out of trouble. With this in mind, the offset drivetrain was to give driver (or other components) more room, with the engine set back, will this be necessary? (probably not) Do you want to keep driveline angles as original? Detroit spent lots of time getting them right, probably best ton follow their lead. Question: Is your differential pinion centered or offset? I would line up the engine/trans with the pinion.
I don't know your usage plan, but I doubt it will be heavy hauling where a forward weight bias will be balanced out by cargo. Ultimately you want a fairly equally balanced truck for best braking and handling. Most hot rod trucks are used more like cars, so balancing one like a car (50/50) would be my goal.

 

I agree with the Detroit engineering, I have very little experience as an educated engineer. Mine has been done with no formal training.

 

As far as the cab to engine, mock up with all the accessory drive in place and make sure that you can service and do repair to the front of the engine. For some help with the drive line angles ,down load the tremec app on your phone. You’ll be able to check the angles with the phone by using it as a smart level. It’s hard to explain and it free.

 

Will check it out.