VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 1928 Chevy Four Cyl

I am looking for information and literature for a 1928 engine. I am also looking for a supercharger that will mate to it, for a speedster project. Can anyone on here help?

I was told many years ago that the 1925 K series engine was the best for a speedster. Supposedly because of having the strongest center main bearing ????

Yes, because the center main area is not cut away for
the oil pump/dist. drive. Weak area IMHO, is the cranks,
not the center main, even on '26-'28's. And I would not
use the stock (split at the wristpin) rods either, for
anything over a very mild engine. Model A rods are stronger,
and slightly longer, giving more (needed) compression.
Unless, that is, you can find rods from a Curtis OX5
aircraft engine. They are longer, stronger, and much, much,
rarer- being a WW1 item. Bob Rufi used these on his record
setting car.

Herb Kephart

Look at the Turbo that Chrysler used on their
2.2L four. Stay away from positive displacement blowers-
Roots, Judson, Mehile-Dexter, etc. And keep below
about 5-6 lbs boost. Please keep me informed on this project.
Good luck!

Herb Kephart

I tried looking on ebay for a photo, can't find one. Have you adapted one to a chevy? If anyone has photos of this type of conversion, it would help. I was hoping to find something that mounted between the carb and intake, as opposed to efi style turbos that simply pressurize the fresh air coming in. A supercharger would simply the plumbing problem.

I have one that I intend to use, but haven't done the conversion yet. Im not sure, but I think that mine is early enough to have come from a car without EFI (with carb.) I may be wrong, but I don't think that there are any significant differences in the turbos. In any event, I would mount the carb on the suction side of the turbo, as pressurizing a box surronding the carb leads to problems with keeping the fuel pressure above the manifold pressure by a constant amount. The turbo requires connection to lube oil pressure, feed and drain (more pressure than what the Chevy splash lube system puts out) and to engine coolant, in and out.
It's going to require making brackets, exhaust and intake tube
bending, plumbing etc. etc. You will have to be able to make all of this for yourself, or find someone who will do it for you.
Its a lot of work, but it can be done. In one of the Secrets of Speed magazines some one reported that he had done it to a model A, and was not only impressed with the performance, but also the improved fuel milage. If you want I will see if I can find the letter and it might have a way to get hold of him

Herb Kephart

I forgot to respond to your comment about a supercharger having less plumbing-- very true! However it requires a very significant amount of HP to drive one. A turbo uses the energy in the heat of the exhaust gasses, which is normaly wasted, to do the same thing, for free.
With the exception of the fuel dragsters, superchargers (AKA "huffers") are a thing of the past. Turbos are used on aircraft, nearly all diesel trucks, railroad locomotives, stationary powerplants etc. etc. If you insist on a supercharger, about the only that I know that is small enough would be one made by Judson, for the Corvair, and they were not all that trouble free.

Herb Kephart

It's all well and good to get your '28 performing better,but just how fast do you want it to go before it expires?And then you have to consider just how you're going to get it to stop!
A '28 engine with a few minor mods will perform really well without killing it.All I can see that will happen is that the oil pan will be there to catch everything when it breaks.
Why not just drop a 350 into it,disc brakes etc. and have a hotrod?

:eek: :eek: :eek:

Ok, what kind of mod's are you talking about? I am most interested in mod's to the head and intake. Increasing compression is a given, my engine will have about 6:1. Brakes are a good idea too. As for the 350 engine, it's not an option. Part of the motivation is the bragging rights to be earned. Bragging about a 350 engine in an old car is lame, anyone can do that. Bragging about how you got 100HP out of an 80 year old 4cyl engine is something different. It takes skill, not just a trip to the junkyard or a phone call to Jegs.

Mods like fitting super chargers/turbos blowers etc.The bottom end of these engines won't be able to handle the extra load on them.
Upping the compression ratio to 6:1,a good idea.That's what I did in my '28 truck engine,a full engine balance and maybe a diff ratio change.A decent updraft carb instead of the Carter that has an accellerator pump and a power valve,eg.TILLOTSON JR-1
or similar.
In other words,the use of "period" speed gear would suit the era of the vehicle,instead of modern turbos etc detracting from the look of the engine bay.

:)

As to the supercharger, try looking at a Judsen for a Corvair. It was for an engine about the same size, used a Sromberg 3-bolt style carb vs the smaller setup used on VW's. I haven't had one in my hands but I would think it would be a nice set up.
IF you have the $$$ to buy the Judsen and then make all the mods.

NOTE: The Bonneville record for that size of supercharged vintage engines is still below 100 mph.

I saw this thread and had to drop a question in. I have a 1925 K Series Touring with stock 4-cylinder. I live on an incredibly steep hill. It's 1 mile from the bottom of the hill to my house, but about 3/4 of the way up, the car started slowing down and I was afraid it wouldn't make it.

I just bought the car and have a few things to do. Right away I am going to rebuild the carb (the car backfires and stalls at times) and adjust the timing.

Assuming the carb needs a rebuild and the timing is off, do these adjustments have the potential to add enough power to make the hill with confidence? I don't need much more, about 5% to 10%. Otherwise, I guess I'm looking at a compression increase, or other engine mods/updates, and wondering what's recommended and how hard these are to do. Thanks.

Before we can give you any sound advice we need a bit of background information. Is the engine a 1925? Does it have a modern or original coil, are you using the vacuum tank fuel system? Is the hot air system set up? Is the carburator a Carter and what model?

Data plate information (from the plate on the end of the front seat), numbers from the flat boss on the engine. Date of the engine which is located under the single exhaust port. All numbers and dates from the head.

Give us some info and we will tackle the problem.

OH! and MERRY CHRISTMAS AND A HAPPY NEW YEAR.

Hi Ray,

Here's what I've got so far:

- Coil is replacement, brand "Standard" marked "UC-14"
- Vehicle has vacuum tank fuel system installed and appears to be operative
- Not sure how to identify whether there is a hot air system, assume there is not
- Engine block flat boss is stamped: 2127524
- Data from under single exhaust port, three lines of data:
K 2 5
344624
12
- Data from head, two locations:
J 29 5
344128
5

Carb is Carter CRX-0

Can't locate data plate on end of front seat, may have been removed or obscured by previous owner. If I find it, I will post the data.

Appreciate the help. Merry Christmas and a Happy New Year to you, as well!

Hi jrp,

Your head is dated J 29 5 = October 29, 1925

Your block is dated K 2 5 = November 2, 1925

Your motor number, 2127524, would probably be stamped on the head under the exhaust manifold. If those two numbers match, it would indicate you have an original combination of head and block.

The hot air system, and is very important, is a flexible tube that goes from the intake on the carburator to the heat stove on the exhaust header pipe.

The coil is obviously an aftermarket solution to the ignition system.

The Carter CRX-O, is the correct carburator for the 1925 engine.

The vacuum tank is most likely a Stewart Warner. This is a very good fuel pump for your car. The key to the system is that it must be free of any vacuum or fuel leaks. If there is a very small leak in the system you would notice the results you have mentioned.

If you are able to find your data plate, or if the information is on the title, it can be replaced.

I would recommend a careful tune-up to include valve adjustment.

Timing is very critical to get the last once of power from your engine. After the tune-up, I would recommend you attack the hill and adjust the spark for maximum power. Your controls, spark and throttle, should be located below the steering wheel on the dash.

Hi Ray,

Thanks for the great info. I will look again to see if I have matching head and block. Based on your description, I do have the hot air system, didn't know what to look for before.

Is there any point in replacing the coil? How do I test the vacuum system for leaks?

I'm definitely doing the tune-up and valve adjustment. Is there any reason to use a timing light or should I just find top dead center with the #1 spark plug out and a screwdriver in the cylinder like the manual says? (And is the cylinder closest to the radiator #1? Dumb question, I know, but I can't find this in the manual.)

Last time I drove up the hill, I adjusted the spark, the throttle and the choke constantly to get the best settings, and wouldn't have made it if I hadn't. (Nice of Chevrolet to put those on the dash and allow manual adjustment!)

Any way, have a great New Year and thanks for your help. It'll take me a couple weeks to get everything done and I'll let you know how the next hill climb goes!

Joel

There are no dumb questions, at least I have not heard any.

Yes, #1 is at the front of the engine near the radiator.

As to the vacuum tank: Put a wrench on every connection from the fuel tank to the carburator.

As an experiment, you can remove the top of the vacuum tank, fill the tank almost full of fuel and then try your hill. You can get about 7 miles from the tank of fuel.

A timing light can be used for timing the 4-cylinder engine. I have the best results from listening to the sound of the engine.

I may have not been clear on the matching numbers. You must remove the exhaust manifold and the number should be stamped on the flange that was covered by the manifold.

Don't hesitate to "come on back" with more questions.

I still don't have all my parts in one place yet, and still considering options. Has anyone installed a CHEAP fuel injection setup on these engines? I know Moon or Retrotek make a new stromberg setup, way too much money for me. I'm hoping someone on here can give me a blow by blow on how to install something out of a junkyard that will work reliably. Anyone?

Is this for your Poor Mans Rajo (Chevrolet head cobbled onto the Model T engine)?

http://gen3antiqueauto.com/PoorMansRajo.html

That is a rough mockup I did for someone that wanted photos, yes. The actual engine is still in the works.