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Engine Swaps: How "universal" are various motors and chassis?

I always wondered how people installed an engine from another car (same make, but not the identical motor, that is)

Within a make of car, do all/most engines have the identical mounting points?
If not, how can this even work?

One the engine is seated/mounted, is the rest very hard to fit? Or does it require some custom work / jerry-rigging)

Hoses to radiator may now vary? Cut to length?
Some wired connections might need to be extended?
Exhaust manifold might need a new clamp installed?
etc?

Just how crazy does it get when you install a random engine into a car?

How crazy?
If you are dealing with a donor engine and a “recipient” vehicle from the era of ECMs and TCMs, it can be crazy enough to make it virtually impossible.

Back in “the old days”, it was possible to buy adaptor plates that would enable you to mate an unmatched engine and transmission. Some guys were even able to create engine/transmission adaptors on their own, if they were very talented. Unfortunately, I don’t think anyone nowadays can get a modern engine to run properly unless it is installed along with the correct ECM. And, even then, that ECM might not communicate properly with a “random” TCM.

Todays emissions laws and electronic engine controls make it almost impossible to create hybrids like a Fordillac and a Studillac or dropping a 394 cu in Oldsmobile J-2 V8 into a 2-door Chevy…Those fun days are OVER…

Money and Time is all it takes. With a welder , steel and tools to cut it you can make it fit. Their are company’s that make wiring harness for most any engine. If I wanted to put say 2011 Chevy 5.3L V8 in say a 2008 Mustang. I could do it. Why does not matter it can be done and it will run fine. As to how its done. You cut out the old mounts and make new ones. Make or have made a new drive shaft. A custom wiring harness will connect to the computer and the car. Custom radiators can be ordered. Like I said time and money.
Caddyman is right the fun days are over for the old swaps. Now days if you want to make more HP you work with what you have.

Oh, it can be done. Just takes a little more work and time. I know some MR2 guys who are running modern V6’s in place of the original 4. It involves replacing a lot of stuff you wouldn’t even think you’d have to replace, such as throttle cables, etc, but it can be done.

As to the OP’s original question, the easiest way to know if a swap is going to be a direct bolt-in, is to see if the donor car was sold with the same motor as the recipient car (for instance, the stock 2nd gen NA MR2 motor was also in the Camry, which means the two cars are interchangeable in the engine department (but not necessarily transmission).

For motors that aren’t direct bolt ins, if it’s a common swap, there are often kits available. For instance, a common swap for a CRX is to drop an Integra engine into it. There are (or at least were, not sure if they’re still out there) kits with all the different engine mount hardware pre-made for you.

Well, with HUGE money it’s physically possible, but it won’t pass any inspection (modern car), so there’s no point.

For what engine will fit what car without a whole lot of work and money, take a look at www.car-part.com That’s what I generally use as an interchange manual. If you have a car and engine in mind, it will tell you whether it’s practical or not.

Anything before the OBD-II era (beginning in 1996) will be hard to make work in a later car, even of the same model. It’s a computer issue.

There are two types of motor swaps. 1 is where you replace a blown motor with the exact same motor from a salvage yard or remanufactured motor. The other type is putting a bigger motor in a vehicle that the motor it came from the facotry with. This is customizing and that is a whole nother animal. In states with rigid emission rules it really isn’t possible anymore. If you are drag racing or track racing you can do what you want, but if you want to register the car and drive it on normal roads you’ll have to meet DMV and emission requrements that can be outrageous.

I remember back in the 1950s seeing a Buick V-8 engine installed in a 1953 Studebaker and a Cadillac V-8 installed in a 1951 Mercury. These installations required some modifications to the engine compartment and some welding.
Engine swaps for a different engine were not always easy. I owned a 1947 Pontiac with a 6 cylinder engine. When I discovered that the block was cracked, I thought about an engine swap. The only engines I could find were the inline 8 cylinder engines in the local wrecking yards. I talked to a mechanic that worked at the Pontiac agency and even this was not a drop-in swap, and was not really feasible for a car that I bought for $75. I bought a can of K & W seal for less than $5 and it held for the year that I owned the car. Two years after I sold the car, it was still on the steets and I doubt that the engine was replaced.

Ok, forget engine swaps from different makes.
And good point about ECU compatability.

What about something like a 1989 Chevy motor into a 1995 Chevy?
What about something like a 1998 BMW motor into a 2003 BMW?

Is this possible? Are THOSE motors generally identical in mount points?

Computer problems would likely prevent those, 5 years is HUGE in engine electronics development. But that’s where the ‘exchange manual’ comes in, it’ll give the accepable options.

Manufacturers tend to keep successful engine designs for a fair number of years…The Chevy V8 being a prime example, the basic design unchanged for 58 years… Ford has used it’s “Modular” engines since 1992…But other manufacturers will change their powertrains every few years, bringing out a whole new “family” of cars with new engine designs…Interchanging parts between these different “families” is almost impossible even though the basic design is the same…A bigger problem is the electronic interfacing which can change every 6 months if a manufacturer is having emissions or drivability problems…

It’s always the same question…“Speed costs money…How fast do you want to go??”