VCCA Home Forums GENERAL DISCUSSION General Discussions 1928 Chevy coupe motor swap

1928 Chevy coupe .... Can a person swap out the 4 cylinder original motor for a 6 cylinder? If so what has to be changed if anything at all? Thank you !

It can and has been done, but why? A stock 28 Coupe is a fun vehicle to drive and own in the original stock condition. Before you make any moves that are non-reversable talk to owners of stock 4-cylinder vehicle, in fact, you can probably find someone who has one that will let you take it on a test drive. I think you will be pleasantly surprised.

Hey Dion,

Welcome to the VCCA's Chatter forums.

Are you contemplating purchasing the car or is it already yours? Either way, I agree with AntiqueMechanic's suggestion.

If it is yours, drive it stock for a while before making any decisions. These old cars and trucks have great personalities and the general public loves to see them in action. Especially as a survivor.

Cheers, Dean

A word of caution when swapping an engine on a pre 55 vehicle. Most states used the engine number on the title as the VIN through 55. IF that vehicle has the engine number on the title and the engine is removed from that vehicle you'll have a dickens of a time ever transferring ownership in the future. Every state has a method of retitling after an engine swap so the issue can be fixed but you need to take that into consideration.

as noted above anything is possible, just depends on time money and knowledge

these early Chevrolets are not completely interchangeable, so much was changing each year that not everything is.

in regards to a 1928 AB if you were to swap the easiest would be to a 29 AC, per the interchangeability chart i have the 1928 AB has a longer chassis that was used in 1929 for the 6 cylinder. and would have to swap the engine, trans, and probably the torque tube. probably have to create mounts to bolt up the 29 AC driveline into the 28 AB since the 4 is shorter than the 6.

6 cylinder motor will not fit in 1928. On 1929 the firewall is recessed to fit 6 cylinder.

I own one but yet to have it out on the road. I was told by a few people that I would not like the speed of the car and to put a 6 cylinder in it. I guess I will wait until spring to run this ole girl. I am just checking my options over this winter. I will make up my mind when I can take it out. How fast does this car go? I was told it tops out at 30 mph... Thanks for your reply!

We have a 28 Coupe and take it on 4 cylinder tours. Ours will cruise at 45 I have had it over 50 but remember the rest of the car is not designed for much faster.

Ray and Dean are right try it the way it is before any modifications. Many 28 owners keep their cars at 45mph or less. That is a good speed for the time WHEN a moron pulls out in front of that slooooow old car. You will have to get it stopped right away. Notice that is when not if, because EVERYONE knows that old cars are slow. That being said it will do 50 without hurting it. Really noisy and humming but not being hurt. With a 27, or 29 rear end gear set it would do 55 without damage, but that would be faster than the brakes can safely stop it. Just plan your route wherever you are going to keep on the back roads and enjoy the ride. As is it is a cool old car. Once modified its just another hot rod, you know - a belly button car.

Art

The 28’ engines are the only engines chevy put aluminum pistons in stock with both prior and many later years being cast iron. The 28’ engine is “snappy” on throttle response and and makes the car a fun driver. They will easily cruise 40-45 all day if the motor is in good shape. Oil the valve train prior to every drive and there’s no upper oiling system. There is usually a felt/canvas pad that sits on the rockers under the valve cover that helps hold the oil and its oiled through the holes in the valve cover. Make sure you have the air intake metal flex hose from the carb to the exhaust air can/breather/filter. The 28’ is prone to icing up the intake and the exhaust to intake hose is critical for preventing the issue especially at higher speeds. When the intake ices up, the fuel doesn’t atomize correctly and the car won’t run well or not at all. Here in New England with the summer’s being hot and humid, the icing was a real issue with my 27’. With the correct flex hose and exhaust can, it went away. If your Stewart vac fuel pump doesn’t work or has been bypassed with an electric pump, the Carter carbs can only take 3-4psi before the float is overcome. You need a quality regulator if you go the electric pump route. The 28’ is a four wheel braked car so if they’re adjusted correctly and in good shape, you have the best year 4 cylinder chevy to have. Was it model T Ford guys who told you that? The 28’ chevy is a similar type driver but it’s so much nicer and I’ve owned both. They’re just jealous and are going to hate you driving by them!????

I have a stock '28 Coach, and due to the stock carb being worn out I replaced it with a Zenith 267, which is a great improvement, and makes it feel more powerful.

Then in a moment of stupidity which a man of my age should have grown out of, I put my foot down on a straight stretch of road and my phone speedometer app showed it holding 61 mph! This got properly scary and not recommended even for a minute or so.

The motor was quite worn at that time, so a good one should be even better.

Therefore before replacing the stock engine I would consider fitting that carb, you won't regret it. Maybe keep your original one on a spare manifold to refit if you want to show the car as original.

As others have said 45 mph is just about right, you can stop ok ish at that speed.