1947 to 1952 Engine Swap

A

ailimac

Member
Help please. I am new to the forum and also new to Buicks (my last project was a 36 Dodge D2). I recently purchased a 1947 Buick Special Sedanette Series 40. The car needs a total rebuild. As far as I know it has the original 248 staight 8 in it, which I have already removed. I got some advice from another forum and was told I can use any 263 straight 8 from 1947 to 1952. So when I came across a running 1952 263 engine I bought it (stamped engine ID 56094594, casting number 13880207). I was told I would just have to switch the front mounting plate from the 47 to the 52 and remove the side mounts on the 52. My 47 has a manual transmission. Now I am told that the 52 engine, which had an auto trans on it won't fit the 47 transmission. Is this true? If so is there anything I can do. The auto trans from the 52 is available to me if I want to buy it but will that fit in my 47 without any major modifications?
And what about switching the front mounting plate. The harmonic balancer doesn't have any holes to use a normal balancer puller. I tried using a hydraulic gear puller but only got it to move 3/16" (on the 47). I think I may be fighting the balancer against the hydraulic jack now. Before I continue to try and get the balancer off I would like to find out if I can even use the 52 263 engine.
I would greatly appreciate any advice.
Pete
 
Pete,
Use the front mounting plate from the earlier engine on your 263. Swap it out with the plate that's under the 263's timing gear. You may have to look at the 263 block, compare the holes in the two plates, and drill extra hole(s) in the earlier mount plate... Not a big deal. After drilling the hole(s), chamfer the edges slightly to remove any drilling burrs.
Use the 248's bellhousing on the 263 block. You'll need this because it's what the 3 speed tranny is bolted to, and there's rear motor mounts that attach to said bellhousing. The 248 bellhousing bolts directly to the 263 block.
If your 263 was originally equipped with a dynaflow you'll need to remove the adapter extension bolted to the back of the 263's block in order to bolt up the 248 bellhousing. The extenson was used to bolt the dynaflow tranny to. In this case you should obtain a 263 flywheel, which may need it's cener hole enlarged to physically fit on the 263 crankshaft rear snout. You'll also need to have a pilot bearing adapter machined to fit in the dynaflow equipped crankshaft, as the hole there is larger in order to mate to the dynaflow torque converter.
You can eleminate steps in the 3rd paragraph by using a 263 that was OEM equipped with a 3 speed. However, the 248 bellhousing is required. Early 248's had 4 engine motor mounts and a tranny mount. The latter 248 and all 263's have 2 motor mounts and a tranny mount.
To remove the front dampner, I used a gear puller that had claws on it. Once the dampner begins to move it should wiggle off the crankshaft snout. Practice with the 248 engine 1st and pulling the one off the 263 will be a snap. However, clearly mark them as you do not want to mix them up. John
 
Last edited:
Thanks John. Sounds pretty straight forward. For a minute I thought I may have had to sell the engine. Once again, thanks very much.

Pete
 
Pete-
The reason for the issues with the switch the engine from the automatic to the three-speed transmission is that Buick used different crankshafts, depending on the type of transmission. The Dynaflow flexplate connects to the crank with machine screws, and the flange on the rear of the Dynaflow crankshaft is thicker to accomodate the threads for the machine screws. The three-speed crankshaft uses bolts through the flange, which are inserted from the front, with washers and nuts snugged to the flywheel.
I recently converted a 51 Special from automatic to three-speed. When faced with the same set of problems, I located a crankshaft from a three-speed 263, and avoided all of the issues with mating the automatic crankshaft to the three-speed. And, because I tore apart my 263 to switch cranks, I discovered it was running fine, but with six cracked pistons. Who knew?
--It may be possible to use the machine screws that originally connected the flexplate to the crankshaft to bolt up the flywheel. i did not try this as the machine screws are a good deal less stout.
--In order to bolt the flywheel to a Dynaflow crank, you will need to drill out the existing threads, and also remove the pan and rear main bearing cap to insert the bolts. I am unsure of the effect, if any, of the difference in thickness of the Dynaflow crankshaft flange (thicker) and the three-speed crankshat flange on fitting the clutch. It is pretty tight within the Buick bell housing.
-- As JR9162 noted, the snout of the Dynaflow is much larger than the front shaft on the three-speed, and you will need an adapter to mount a pilot bearing. I located a shop in Florida that makes these adapters for the nailhead v-8s, and was told by the owner that the adapter should work with the straight eights. Because I changed my crankshaft, i never followed up, but could probaly find the contact information if you are interested.
Good luck with your 47.
'51 Special
 
Thanks for info 51.
Let me ask you this. What if I used the auto transmission instead of trying to adapt the manual transmission. Would it fit in relasonship to the drive shaft or motor mounts? Would I be looking at any major modifications down the line? The person I bought the engine from still has the auto trans and is willing to sell.
Thanks again.
Pete
 
ailimac said:
What if I used the auto transmission instead of trying to adapt the manual transmission. Would it fit in relasonship to the drive shaft or motor mounts? Would I be looking at any major modifications down the line?
Click to expand...

Adapting the Dynaflow crank to the manual flywheel will be MUCH less work than trying to install a Dynaflow in a 47 or earlier car. You can do any necessary mods on the crank flange without having to remove the crank from the engine. On my swap I kept the threads in the flange and made new bolts that go through the flywheel from the clutch side.

Your major challenge with the Dynaflow is that it has no provisions for attaching the 47 rear mounts. If you compare the Dynaflow and manual bellhousings, the difference will immediately be evident.

Ray
 
Last edited:
ailimac said:
Thanks for info 51.
Let me ask you this. What if I used the auto transmission instead of trying to adapt the manual transmission. Would it fit in relasonship to the drive shaft or motor mounts? Would I be looking at any major modifications down the line? The person I bought the engine from still has the auto trans and is willing to sell.
Thanks again.
Pete
Click to expand...

Pete-Sorry to take so long to respond. I was off-line for a few days. Raycow is absolutely correct about the problems with stuffing a Dynaflow into your car. He didn't even get to issues with finding and switching in a later steering column, and that no one manufactures a floor shift conversion for the Buick manual transmission. Ray's suggestions for connecting a flywheel to the Dynaflow crank make a lot of sense, and would be a good bit simpler than what I did.
 
Tranny Issue

Now that I have decided to go with the manual trans I began trying to get the trans off the old engine. I have been trying for 3 days and can not get the trans off the motor. I got it to move about 3/4 of an inch and thats it. I've been soaking the shaft thru the bell housing with rust desolver but nothing. I can spin the transmission around but the shaft stays stationary. I've tried prying it with an 8 foot bar. This tranny doesn't want to come apart. I'm trying not to destroy anything. Wednesday I am going to hang the engine by the transmission on an engine hoist and try and use the wieght of the engine and the pry bar to get it to separate. I am definetly going to video this, just in case I crush a leg or something.
I double checked all my manuals to make sure I didn't miss any hidden bolts or set screws but found nothing. As anyone had this type of issue before?
Pete
 
ailimac said:
I've tried prying it with an 8 foot bar. This tranny doesn't want to come apart. I'm trying not to destroy anything. Wednesday I am going to hang the engine by the transmission on an engine hoist and try and use the wieght of the engine and the pry bar to get it to separate.
Click to expand...

Don't apply force on the bellhousing to adaptor ring joint or you will damage the converter. The same goes for the case to bellhousing joint. I mentioned both of these because I'm not sure where you are prying just now.

The Dynaflow is unlike any other automatic transmission that you have ever seen or worked on. To get it off the engine, you will need to remove the bolts around the edge of the converter that hold it to the flexplate. There is a hole in the adaptor that will give you access to the bolts. Drain the converter first or else you will get very wet. There are two plugs on the converter about 180 degrees apart for this purpose.

Once you get the transmission off the adaptor, unbolt the flexplate from the crank. You will then be able to get to the inside bolts that hold the adaptor to the engine. The rest of the bolts are on the front side where you can see them.

If you want to get the converter off the transmission, you first have to take the transmission off the engine as described above. Then take the converter apart from the front.

Ray
 
Last edited:
raycow said:
Don't apply force on the bellhousing to adaptor ring joint or you will damage the converter. The same goes for the case to bellhousing joint. I mentioned both of these because I'm not sure where you are prying just now.

The Dynaflow is unlike any other automatic transmission that you have ever seen or worked on. To get it off the engine, you will need to remove the bolts around the edge of the converter that hold it to the flexplate. There is a hole in the adaptor that will give you access to the bolts. Drain the converter first or else you will get very wet. There are two plugs on the converter about 180 degrees apart for this purpose.

Once you get the transmission off the adaptor, unbolt the flexplate from the crank. You will then be able to get to the inside bolts that hold the adaptor to the engine. The rest of the bolts are on the front side where you can see them.

If you want to get the converter off the transmission, you first have to take the transmission off the engine as described above. Then take the converter apart from the front.

Ray
Click to expand...
Im sorry Ray I didn't make it clear that I was trying to separate the manual trans from the old engine. I removed the 4 tranny bolts and am prying between the trans and the bell housing.
Pete
 
Now that is really strange. It sounds like the transmission input shaft is rusted into either the clutch disc or the pilot bearing. How long has it been since the car was last driven?

Ray
 
Ouch! Well that explains a lot anyway, except for how to get the thing apart.

You said the transmission is about 3/4" away from the bellhousing. If you hang the engine/transmission assembly with the input shaft pointing down, do you have enough room to get in there and dribble penetrating oil down between the shaft and the release bearing support sleeve? Maybe use a piece of small diameter flexible tubing on the spout of your oil can?

Don't forget to drain the oil out of the transmission before you hang it. Probably a good idea to drain the engine too.

Ray
 
Last edited:
Pete- From my experience removing a manual transmission from a '50 Super that had sat belly down in the dirt for many years, and mice had nested within the bell housing, I believe the clutch driven plate in your '47 has rusted to the front shaft of the transmission. I assume the engine is frozen, and that you cannot effectively depress the clutch pressure plate with the peddle. It may help to get the clutch release yoke out of the way. That helps if you are trying to pry between the throw-out bearing and pressure plate. Also, before you follow through on the idea of hanging the engine and transmission, remove the torque ball (so you can get a grip), put the tranny in gear, and try to turn the shaft back and forth to break up the rust. if you must hang the engine and transmission from the transmission, you need to lift it so the bottom of what you are lifting clears your floor by only an inch or so. And stand well back if you attempt any prying. If it comes apart, you are going to have close to half a ton of iron trying to find a place to be. '51 Special
 
ailimac said:
Im sorry Ray I didn't make it clear that I was trying to separate the manual trans from the old engine. I removed the 4 tranny bolts and am prying between the trans and the bell housing.
Pete
Click to expand...
For my understanding,You mean the 4 Bolts from the Bell to the Engine,or the 4 Bolts from Tranny to Bell ? I ask,because between the Bell and the Engine are 2 Bolts from inside the Bell to the Engine. You can only loosen they when you first put out the Clutch and then the Flywheel. Maybe Anybody in the past Time has "forgot" this 2 Bolts then you have now with the Clutch and Flywheel on theyr Place the Problem like you described....only an Idea from me ..
 
Last edited:
51 Special, you out there?

I was wondering if you have the contact info for the guy in Florida who makes the adapter you spoke of (dybaflow crank to 3 speed manual).

Thanks.
Pete
 
Pete, does this mean you were able to separate the trans from the engine? If yes, how did you do it?

Ray
 
Oh yeah, it separated. IMG_2481.jpg After 2 wedges and 20 or 30 wacks with a sledge it finally snapped. IMG_2510.jpg I had to cut the broken end of the trans shaft out of the bell housing with a cut off wheel. The broken end of the trans shaft is still and will forever remain stuck in the clutch. IMG_2518.jpg Oh, I also had to remove the crankshaft to get at the flywheel, clutch and pressure plate because of all the rust. I have the new engine, and the trans is rebuilt, all I need is the adapter to get the manual trans to the Dynaflow crankshaft. Unless I find a manual 263 crankshaft. IMG_2469.jpg IMG_2744.jpg I have some feelers out for the adapter cause I'm told there's a few shops that make them but have not had any responses yet. IMG_2278.jpg I've completed most of the front end so has soon as the engine and trans are ready I can drop them right in. IMG_2732.jpg Pete
 
WOW! In my entire lifetime of working on cars, I have never seen anything like that. Now I understand why you had to sacrifice the bearing support.

Since you are painting the trans case, does this mean you have already found a replacement input shaft?

Ray
 
Yes, found another 3 speed and harvested the internals an did the rebuild myself. The spare trans I bought didn't have the bolt holes on the casing for the trans support so that's why I had to swap the internals.
 
You must log in or register to reply here.
Back
Top