Two unknown engine cylinders

[Larrythepilot]

Our museum has an old furnace room full of WWII aircraft parts that were buried after the war, and then dug up 50 years later, in the late 1990's. A lot are engine parts, and many of them are engine cylinders. We have succeeded in identifying most of the cylinders, but there are 2 of them we need help with. Our President, Joe C. has just taken photos of several views of each of the two cylinders. Can any of you help us to learn what engines these cylinders came from? Thanks.

Our goal, by the way, is to create a cylinder display, consisting of about 10 different cylinders. Each cylinder would have an accompanying written description, a photo of the whole engine, and a photo of the airplane in which it was used.

 

[mjfur]

The black cylinder is Japanese based on the Chrysanthemum stamping.

 

[mjfur]

The second badly worn cylinder appears to be for a version of the Bristol Mercury engine. Your cylinder has a direct injection hole on the front.

Edit: Direct Injection https://de.academic.ru/pictures/dewiki/66/Bristol.mercury.arp.750pix.jpg

 

[Larrythepilot]

Mjfur, thank you for identifying the one cylinder as being from a British Bristol Mercury engine. I have made notes, and copied one of the pictures you sent along. I see that the Canadian Air Museum in Langley, BC has one of the engines in a plane in their museum. I get out that way occasionally because my wife's son lives near Seattle. I may pop across the border and have a look.

Now, if somebody comes up with more complete information about the other (black) cylinder, I'll be in really good shape. Your note that it is Japanese is a good start.

 

[mjfur]

Based on the air scoop in the original WWII photo I'm guessing the aircraft was an H6K Mavis. Kawanishi H6K - Wikipedia

https://c8.alamy.com/comp/D40TAA/kawanishi-h6k-mavis-D40TAA.jpg

Engine types listed in link.

 

[Engineman]

Hi Larry,
The "Bristol Mercury" cylinder could also possibly be a Bristol Pegasus. These two engines were very similar, both with 5.75inch Bore, but the Peggy with 7.5inch stroke compared to the standard Mercury with 6.5inch stroke. The stroke might not be simple to measure on your bore, but possibly it can be? If the bore condition is not good enough to measure the stroke, you might have to try finding someone with a Pegasus or a Mercury to compare the cylinder. Certainly 1 inch longer stroke is a fair amount that should make measuring fairly easy.
Sorry I don't have measurements for the cylinders. You would get info from emails to the Bristol branch of the RRHT.
Cheers

Eng