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Buick straight 8 for straight 8 engine swap


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I've got a '37 Buick 46S Sport Coupe with a 248 straight 8, likely original to the car.  There is some serious internal problem going on.  Engine turned and started five years ago but there is problem deep in the engine - crankshaft, rods, piston - who knows?

 

Car has been held hostage due to a long running divorce - now five years and no end in sight, though I have been told by lawyers and court official to expect another 18 months.

 

However, I have been thinking of obtaining another straight 8 engine and having it rebuilt.  I am at the age where time is now more valuable to me than money.  I figure if I get a rebuilt engine, by the time it is ready I could have the car back, and "just drop the new engine in."  What could go wrong?

 

The engine I am looking at is a 1951 Buick 263 - with non-Babbited bearings, which makes it more attractive to me.  It's mated to a standard transmission in the donor car, and of course my '37 is standard transmission also.

 

Am I correct that the 263 engine swap for the 248 should be pretty straightforward?

 

 

 

 

 

DSCF3792.JPG

Edited by gregleck
typographical error (see edit history)
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Real handsome car you have! 

 

I may be wrong on the years, but i believe the later 1950+  263ci engines, used side motor mounts located in the middle'ish of the block  rather than a front timing cover mounting plate like the 1937 would have.  I'm sure its doable to build side mounts off of the frame to mount it, but sticking with the a slightly earlier 248 engine with the front mounting plate seems like it would be alot easier. The later mounting plates are shaped slightly different than the earlier horizontal ones that would sit directly on the frame, rather than in an engine cross member with slanted mounts. I believe the move from babbited bearings was around 1948? and if you are rebuilding the engine, locating some later connecting rods with insert bearings could be something to consider.   I have a 1947 engine in my 1937 Century, and had a hard time finding the correct earlier plate, so i modified the later one to work, but if you are swapping engines, you could swap your plate over as well if you are not able to find another one. 

Edited by Stooge (see edit history)
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Side front mounts from 1948.

My understanding 1937 front plate will bolt to the 1951 engine.  Does for 1939

May need to use the 1937 bell housing to have the rear mounts and transmission fit up

This conversion has been done many times before

Edited by 1939_Buick (see edit history)
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40 minutes ago, 1939_Buick said:

 

My understanding 1937 front plate will bolt to the 1951 engine.  Does for 1939

 

That's one that i wasnt sure of, if the earlier plates would fit under the timing chain and cover of the later side mount style engines

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I would suggest that it is likely fairly easy to break the original engine free. That would probably be easier than doing the swap. The basic process would be to pull the plugs, add solvent to the cylinders and allow them to soak for several days. When you pull the plugs, also pull the valve cover and push rod cover and make sure the pushrods and valvetrain are lubricated and free. Remove the flywheel inspection cover and you can likely use a small pry bar to turn the engine by prying on the flywheel ring gear against the side of the bell housing. If you want to go a bit further, you should also pull the oil pan so you can easily acces the underside of the pistons. You may find that there is some surface rust one or more cylinder walls (especially if the car has been stored in an non climate controlled location.) 

 

Dave Tacheny has told me that he has never found a seized Buick straight 8 engine that he could not break free. A friend recently purchased a car that had been sitting in a non climate controlled storage space for 16 years. We pulled the oil pan on that one, and found a bit of surface rust on one cylinder wall. A little bit of solvent and wire brushing that cylinder wall along with the previous solvent soaking and the prybar broke it free. It was running as good as new after just a short time due to using this process. 

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2 hours ago, MCHinson said:

I would suggest that it is likely fairly easy to break the original engine free.

Engine is free already, or at least it did a year ago.  As part of the divorce the car had to be valued and the evaluator said the car cranked but would not turn over.  Not surprising considering it was last started over 4 years ago.

 

But I do know there is a major problem and the engine needs to be taken at least partially apart to diagnose it.  But I cannot do anything with the car until the divorce is over, and that is going to take at least another year and a half.  That's why I thought I would move ahead with plans to build a new engine now.  

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Please explain what symptom(s) lead you to say, "there is a major problem and the engine needs to be taken at least partially apart to diagnose it". Also, If you need an engine, it would be much easier and probably cheaper to simply get the correct year engine to replace it. I suspect Dave Tacheny would have one if you need one. 

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Lots of loud noise.  Exhaust manifold is also cracked.

 

Someone who rebuilds prewar engines took a look at it - put a long piece of wood against the block to use as a listening aid and the knocking seemed to originate down in the crankcase.

 

I purchased a lot of odds and ends from Dave back in 2014-2015.  Is he still active?  

 

 

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You will need a 1937 intake-exhaust manifold as intakes starting from 1939 have a step. Repro exhaust manifold are made

To build a new engine for your car, based on a later block/head, will need various parts from a 1937 S40 engine

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3 hours ago, gregleck said:

I purchased a lot of odds and ends from Dave back in 2014-2015.  Is he still active?  

 

Yes Dave is still selling 1936-1941 Buick parts. You can probably buy a good 1937 engine from him cheaper than you can rebuild another one.

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During World War II many prewar Buicks were driven until the engines wore out. After the war Buick designed straight eights to double as replacements for worn out engines in prewar models and for use in new model post war cars. A 1951 263 will work in a 37 special by using a 37 timing chain motor mount and possibly the bell housing. Be sure the crank in the 51 is not for an automatic transmission. Too bad you live so far away, I may have a 37 short block.

                                       Thanks

                                           Leif  

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If you will you  decide to swap it,here my experiences :

I had done it too on my '38.

The old Frontplate will work fine on the 363,also the Flywheel (attention here,marking the location on the crank!,it will fit in all positions if you don't mark it).

All Aggregates from the 248 will fit,(also my better looking small '38 Fuelpump),

except the Waterpump,Thermostat housing and its tubes, that you need with the Engine.

The 2 upper threads from the 263 sidemounts you must block with its srews, because they goes into crankcase,and starts otherwise to leak.

May be you have problems with the position of the crankcase ventilation tube on passenger side, the rocker cover from the 248 looks like similar but doesn't fit to the 263.

But this is peanuts ..;-)..

 

M2C

 

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On 1/11/2021 at 3:33 PM, 1967 - 1997 Riviera said:

 

Whatever you do, please do not scrap the engine that is in the car now.

Wouldn't dream of it.

 

Once it is out I will tear it down to see what happened, then have it rebuilt.

 

I actually found a 1937 248 engine.  It is running but I will still take it apart to replace the babbited pistons and use metal insert bearings.

 

Thanks to all for the tips and tricks!

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