Packard Forum Index » Post-War (1946-54)

Owen,
The reason for my doing the engine swap is due to finances.
I am not being sarcastic by any means but economics dictate what my options are.
Tommy

Understood, thanks for clarifying.

On the Cad 374 engine swap:
I don;t know how many engine swaps u've done so i'll just outline a few points to watch:
1. Steering gear clearence. This could be a major issue especialy with any big block.
2. Keeping centerline of engine crank and trans outpur shaft close to the same center line of the OEM engine.
3. Watch for any offset that mite be in the rear axle pig. If it sets closer to the left wheel it could create a bigger problem as stated in point #1 above.
4. I doubt that the any of the streight 8 or 6's were offset from longitudinal centerline of car. But something that needs to be checked. Otherwise drive shaft could be on an unusual angle.

Keep us posted on your progress. Interesting project.

Personaly i see no problem with the Caddy engine in terms of reliability relative to any SBC so roadside breakdowns are probably the least of worries. Especialy since u are getting an engine u already know.

PackardV8

Thanks for the info. I am capable of doing my own body work welding, using the english wheel, forming dollies and paint. I have built 3 Model A including a boat tail speedster from the ground up but that's the extent of my knowledge. Model A's and body work is pretty simple and somehow the engine swap of the Packard has be a little intimidated since from my world my group of close buddies call them moderns. I know from experience somewhat about gear ratios and alignment but on a Model A that part is simple as there are not as many variables as the Packard. I understand that the engine and trans. must be mounted level but driveline alignment has me a little bewildered as of yet. As I stated, I am wanting a daily driver and be able to drive 65-70 with a low engine rpm. If I had my druthers and the finances I would not change out the engine, however I must live within my financial situation. Again thanks to all for all of your input. I am sure I will want to pick your brains for info again.
Tommy

The driveline alignment concerns the angle of the 2 u-joints. To prevent driveline vibration the angle of each u-joint must be identical. A small tolerance is OK (say 1 degree) to account for measuring errors and suspension movement. If the engine crankshaft is perpendicular to the rear axle (viewed from the top) then the u-joint angle is measured in a vertical plane. Do not assume the crankshaft is parallel to the rear axle pinion shaft. On some cars the rear of the crankshaft is lower than the front to enable the drive shaft to sit lower in the car. That angle on the front u-joint is compensated for by tilting the rear axle housing to obtain equal angles on both u-joints. On many cars this rear axle tilt is accomplished by a locating pin welded to the axle housing. Be aware of these engineering requirements when swapping engines, drive shafts, and axle housings.

BEFORE removing the Packard engine and trans:
Pick some convenient point of reference such as a frame hole or original engine mounts. MEASURE from that point of reference to the center of the crank at the front of the engine. That gives a horizontal location. Do the same thing to get a VERTICLE measurement. RECORD the measurements.

Pick another frame point-of-reference near the output shaft of the transmission. measure from that point of reference to the centre of the output shaft or u-joint of the trans. GEt a verticle reference point to. Record those measurements.

Swing the caddy engine and trans into the car and position it as close to the reference measurements as possible. Block it up or hold in that position by some suitable means while other analysis and inspections are made. Exhaust routing, steering gear clearence etc are things to study and look at for an hour or two.

When making the mounts try to allow for some wiggle room incase the engine has to be shifted one way or the other from original plans.

Also plan ahead for possibility of power brake units (on firewall, Air-con, PS etc.

Just have to think it all thru. Don't rush the job. There is ALWAYS some unforeseen issue that can not possibly be blue-skyed during planning.

Effectively it is a cut-and-fit, cut and refit repeat process that is often repeated many times before final assembly.

Keep us posted. I can not say for sure but i think u are going run into steering gear interference problems. Maybe not.

There is much more to these engine swap issues than is ever revealed by those doing them on a regular or even semi regular basis.

The Caddy is a very large (of external, outer overall dimension) engine. Which can create swap problems in vehicles designed prior to the HP/V8 revolution of 1955.

Note that even the 1955 and 56 Packards have the engine setting about 1.5 inches toward the rite side of the car FOR STEERING GEAR CLEARENCE. This was common among many cars built up thru the early to mid sixties. Corvette is one other i can think of rite now.

However i have not yet measured the 55-56 rear axles to determine if they are offset or not. I mite try to do that this afternoon.

It is all of these kind of issues that, love them or hate them, makes the SBC so suitable for transplants regardless of any other likes or dislikes.

Decisions, Decisions. It will be an interesting project. Putting a 3 foot motor where a 4 foot used to be will have some challenges. PV8 has named a few. Another will be whether to set the engine/trans back to clear steering cross shaft and gear and take advantage of some easier mounting areas for trans which leaves the radiator way up front or move the engine up closer and then maybe have oil pan clearance issues with the steering cross shaft plus all the engineering for the mounts. I think it may wind up costing a fair bit either way you go. Maybe as much and as long a time as fixing originals.

On the alignment question, if it makes you feel better, Packard didn't get it quite right in 56 when first going to the Dana rear ends in place of using their own. A bulletin has the dealers install shims to tip the rear axle slightly or to change rear end ratio to minimize or change the start & duration point of a vibration period around 60 mph. Note minimize, not eliminate is the operative word. They cautioned dealers not to promise a cure. If it takes you a few tries, you're in good company.

I don't think I ever heard--what ails the engine in your car? A ring and valve job can be done with the engine in the car for about $300 for rings and gaskets and sundries. Or if yours is completely toast I'd dearly love to sell you a 50 288 that ran well when I took it out for $300.

What you are describing is a lot of work and not all that cheap either. You'll have $150 in the driveshaft before you blink, will need to ditch the heater etc, etc. Even when bucks down you still have to count your time as something. Just a thought.

Dear PV8, Fred or Ross or whomever,

I need to pick your brains again for more info. When setting the Cad motor in and replacing the straight 8: how critical is the location of mounting the V8 as far as dynamics go meaning engine weight, torque and other things I can presently think of. I know the steering box may present problems but my concern is the difference in the weight of the engines. When setting the front of the engine I understand I may have more clearance from the radiator or by moving it up I may have problems with the trans mount. I understand I can extend my driveshaft, however I feel it sure fit (in my feeble mind) more towards the middle to accomodate for the A/C or other componetry. How much will the weight difference make in the steering geometry? Please advise me as you guys seem to be gifted in the art of engine swapping theories.
Tommy