VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 Anyone out there with a '25 car with a '28 motor??

Howdy guys,
Was hoping I could find someone that is running a '28 motor in their '25 car. I have a '25 4 door sedan.

I ordered an exhaust system from the FS, they have called me back and told me their supplier (I believe it's Waldron's), refused to make my exhaust because the '28 exhaust isn't compatible with the '25 model body. I can't for the life of me figure out why the it wouldn't work at least as far as the exhaust manifold connection down to the straight sections, I could understand that underneath could be a little different, but I could have that portion rebent or remade by a local muffler business.

What say you?

Thanks

There is a fellow in our region (CRR) who has one but it is an open touring car so may be a little different. This car was put together by long time member Red Frey (sp?). It has been updated to hydraulic brakes and 28 running gear. It has been on numerous 4 cylinder tours all over the West. Look through the registry and you should find the new owners contact info.

Jeff you might want to try Gary Wallace. He sells exhaust systems.
http://earlychevyparts.com/

Hi Jeff,

The supplier likely had this come up and maybe the purchaser complained when the header was made too short or too long due to the difference in locations of the two different manifold exit points. I think if you just ordered one for a 28 you can make or have someone make any further alterations needed.

Roger

I was thinking that too Roger. The '25 stops just after the muffler and the '28 extends back to the next cross member. My '25 sedan extends all the way past the body.

Hey guys, I'm pretty sure you are correct. I told Dan @ FS to go ahead and just order it for the '28, but he said they wouldn't do it now that they know I have a '25 body. To be clear, it's not FS, it's definitely the supplier putting the halt on it.

May have to just use a different name and address to get it.

I did call FS back today and asked them if they could just get me the first section from the exhaust manifold to muffler which would include the stove, I could get the rest of it bent at a muffler shop here somewhere, haven't heard back from them yet. I should just order it with the long section straight and not bent at all.

Steve,
Are you referring the length of the straight pipe after the muffler? If so, I don't believe that's what they are concerned about, I think it's more in the engine bay area, but I could be wrong. I was reading here somewhere today where someone was mentioning the length of the straight pipe, how it once stopped just in front of the axel and mid year they changed it to run out the back of the car.

Jeff,
Yes, the 25 ended at the rear of the muffler. You could probably modify a '28 set up to fit your '25. The pipe between the muffler and manifold would definitely be different.

The major difference in the exhaust system in the 1925 versus 1928 is the provisions for the carburetor heating and air filtering. The 25 takes the heated air from the stove and routes it behind the motor to the carb. The 28 has an air filter mounted on the heat stove and a hose that takes the hot air across the back of the engine to the carb.

The fact you have a 1925 vehicle is information overload to the people that make the exhaust system. Order a 1928 exhaust system if you have a 1928 engine. You can make any modifications from the end of the muffler to the end of the car.

Ray,
Thanks so much for the info. You are correct in that I probably should not have provided the info of having the '25 body to the FS, my reasoning for doing so was so that they could alert me if there were major differences. In hindsight I should have brought that question here instead, then ordered the exhaust. Oh well, live and learn. I've got one on order now from Gary Wallace.

I think I can answer your question..the engine compartment on the pre 28s is shorter. The 28 exhaust will hit the firewall.. I saw a pic on here where the firewall had been cut and recessed. The longer 28 engine comp. was in prep for the 29 6 cylinder.. Is that a wrong assumption?

I'm not totally sure, but I'm thinking that the engine sits in roughly the same place 25 vs 28. On the 28's the extra space (originally meant for the larger 6 cyl engine) is between the fan and the radiator (I believe). That's why there is a larger fan shroud on the 28's.

But I'll report back soon, as soon as I get mine installed.

I agree, Jeff. I think the extra engine space in the '28 cars (and 1/2 trucks) was added to the front of the vehicle, thus the one-year only fan shroud.

The engine compartment of the '28 one ton trucks did not get elongated. So, no fan shroud, and yet the '28 exhaust fits okay.

Below are a couple of photos that illustrate the relationship of a '28 exhaust manifold and '27 firewalls.

Keep in mind that these pics are trucks (1/2 ton (same as car, but different firewall) and one ton). I do not know the dimensions or configuration of the earlier firewalls, which is what your question is all about.

Cheers, Dean

Here is a pic of my engine bay, '28 motor with '28 exhaust in my '25 sedan.