Apr 29

Were any Chandler designs used following the Hupp purchase?

There are similarities in engine size and appearance between the late Chandler eight engines and the new for 1930 365ci eight used by Hupmobile in their big model H and U. This has prompted some to speculate that Hupp may have piggybacked off of the prior work done by Chandler on the Royal 85 engine to develop this new engine. There are problems with the theory. There are a few details that are consistent with prior Hupmobile designs. Do any drawings or exploded diagrams of the Royal 85 engine exist that could be compared to see if there are any similarities in engine architecture? Did the Chandler eights use 5 or 9 main bearings?

Apr 29, 2026

Reply to Hupp31…

Replies (27)

· Apr 29

I have very little information on the Royal Eights other than this page from the 1927 brochure that introduced the model that specifies there were 5 main bearings.

· Apr 29

@Chandler-Six Interesting. So both engines used five main bearings, counter-balanced crank, full pressure lubrication, and had a stroke of 4-3/4”. The theory is at least still plausible.

· Apr 29

@Chandler-Six How many Royal Eight/Royal 85 cars survive?

· Apr 29

@Hupp31 as far as I can track there are just three left. I don't have much information on them at this point. This is one of the main goals of this website to collect and documnet these car and help their owners learn more about them. As a side benifit we learn more information about the Hupmpbile transition. I need to did into my files and see what I have about post-Chandler production.

· Apr 29

Here's a link with pictures of one we were introduced to while we were on tour with our 1914:
https://forums.aaca.org/topic/353283-found-a-1928-chandler-royal-8/

· Apr 29

@Chandler-Six Wow. With the level of rarity that cars on both sides of the buyout have, we may never truly know for sure. But based on what I can see so far, the theory still stands. The only real sticking point that I keep coming back to is whether there would have been enough time to make the changes to the existing design and retool between Dec. 1928 and late 1929 when the 1930 models entered production.

· Apr 29

@Chandler-Six That’s quite a project. But a worthy one.

· Apr 29

@Chandler-Six Wow. That is a big project. But I agree with Travis if there ar only 2 or 3 known cars.

Chris, did you invite him to join the new club site?

· Apr 29

@alsancle so if I remember correctly this car was given to him for free as it was such a large project. It’s in a hanger where as a vocation he builds wooden airplane parts like wings. The car is in good hands but no I didn’t invite him to join as he is one of those old timers that doesn’t do computers.

i need to get back there and check on his progress it’s been several years.

· Apr 30

@Chandler-Six Looks like he’ll likely be putting his woodworking skills to good use on that one.

Was it 1926 or 1927 when Chandler introduced their first eight? Weren’t there two different engine sizes?

· Apr 30

@Hupp31 In 1927 they introduced the Royal 8, continued that for 1928. In 1929 with Hupmobile now in charge they had two eights, the Royal Eight now called the Royal 85 and a smaller Royal 75 which was 3 x 4.5", designed and built by Chandler.

· Apr 30

@Chandler-Six Looks very similar to the the big 8. They probably just shortened it a bit to tighten up the bore spacing. I imagine being one year only, there can’t be many 75s either, right?

· Apr 30

I like this 75 coupe.

· May 1

@Hupp31 ironically they seem to have a better survival rate. I know one guy who has or had three of them at one time in California.

Here is one that was last seen in MO:

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· May 2

@Chandler-Six I would assume that for the 75, they followed the typical industry standard of using the six body and stretching the hood to fit the eight, right?

· Apr 29

There are undeniable similarities in appearance of the two engines. Even so, I would expect the blocks would need to be different to change intake/exhaust port locations for a downdraft carburetor.

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· Apr 29

There are definite similarities between the crankshaft designs. I would also suspect that they use the same firing order.

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· Apr 29

How many cubes was the Chandler engine and do any of those cars exist?

· Apr 29

@alsancle The Chandler engine was 3-1/4x4-3/4” bore and stroke. I believe that made it a 340ci.

· Apr 29

@Hupp31 So just a slighly larger bore on the Hupp block?

· Apr 29

@alsancle Yes, 3-1/2” bore.

· Apr 30

Correction, my math was off on the Royal 8 displacement. That would have been 315ci. The smaller Royal 75 engine would have been a 254ci.

· May 2

I’ll go one further than the potential Royal 8/Hupp 365ci connection. I have my suspicions that some of the design and tooling for the Royal 75 eight could have found its way into the Hupp model L eight of 1931. It’s not much of a stretch to say that the basic dimensions of the 3”x4-1/2” 75 could have been tweaked to 2-7/8”x4-5/8” to yield a displacement that would slide right in between the existing sixes and eights. And it just so happens that the 2-7/8” bore was enlarged to 3” for 1932. The real smoking gun would be if the cylinder bore spacing was identical between the two.

· May 2

@Hupp31 I would expect that since Hupmobile took over the factory they made the most use of the tooling and parts from Chandler that they could. After all the cars that Chandler were making were not of bad design or quality in the final years, just just had too models to support. Imagine two different sizes of six's and two different sizes of eights! Way too much variety for the limited size of the market they had. Of course they could not have predicted the stock market crash.

· May 2

@Chandler-Six Chris, the problem of too many models to support seems to have been a common problem.

· May 2

@Chandler-Six The other thing that supports some cross- pollination in the smaller eights it that the Model L would be built in Chandler’s Euclid Ave. plant and it wasn’t released until late spring of 1930 as an early ‘31 model. Plenty of time to make the necessary changes to tooling and cast a new block. From what I can find about the buyout there was a lot of rumor around it. There were repeated articles mentioning that Durant was behind it, which of course wasn’t true. Near as I can figure though, Chandler had assets valued at $16 million and Hupp paid $18 million. You don’t do that unless you’re getting something more than just empty factory space.

· May 2

@alsancle Absolutely. Hupp repeated the same mistake a few years after. Five eight cylinder and two six cylinder models within the 1932 model year. Everyone was trying to jump on the Durant-style, car in every price range bandwagon.