Gears

[PeterT]

Yesterday morning greeted us with a blustery cold snap & skiff of white stuff on the ground. Leaf raking has been postponed. So I took a drive to Bomber Command Museum in Nanton on 'shop day'. Took my camera along & had some nice chats with a few friendly volunteers. One of the sleeve valve radials was opened up displaying its impressive gears. Practicing my photo fx mojo.

 

[Bandit]

Yes I had to take a picture of that setup too. I did not realize those engines were sleeve valve units. Sometimes the engines used are very amazing. The Merlin’s overhead cams with shaft/gear drives too.

 

[PeterT]

I think its a Bristol Hercules but dont want to speculate.

 

[Elektrishun]

Yesterday morning greeted us with a blustery cold snap & skiff of white stuff on the ground. Leaf raking has been postponed. So I took a drive to Bomber Command Museum in Nanton on 'shop day'. Took my camera along & had some nice chats with a few friendly volunteers. One of the sleeve valve radials was opened up displaying its impressive gears. Practicing my photo fx mojo.

View attachment 87975

That should be framed and hung on your shop wall. Very cool image.

 

[skippyelwell]

I wouldn't want to do the timing on that engine.

 

[YotaBota]

Coward, no sense of adventure? LOL

Make one hellova project for the apprentice machinist.

 

[jorogi]

I wouldn't want to do the timing on that engine.

Think of the poor sod with the slide rule.

 

[PeterT]

Hope I'm not barking up the wrong tree misidentifying. Anyway, this video is interesting as it pertains to Bristol's sleeve valve aero engines. The animation shows the funky cylinder sleeve movement.

 

[djberta]

Sleeve valve engines just don't fit in my mind. They have some plus's but they have some big minus's as well.

 

[BMW Rider]

I was down at the museum last month when they fired up both the Lancaster - all four engines, and the Hercules engine on the stand. Pretty impressive amount of noise.

 

[SightlessSeer]

Great pic of the Hercules Valve drive. I actually volunteer with them at the little satellite hanger in Arnprior where we're working the structure for the replica Halifax that those engines are destined for. If you want to learn more about it the website is halifax57rescue.ca . This post has some decent pictures of what's going on at the Arnprior hanger. About 2/3rds down the page there is a picture of a pile of ribs for the flap assembly. I made several of those and machined the flaring dies (dimple dies?) to flare around the lightening holes.

 

[PeterT]

@SightlessSeer thanks for link!

@BMW Rider good reminder. I need to put the engine run dates on my calender for 2027. Apparently they do/did a night show of the Lanc runup because its even more thrilling with short flames crackling out of the exhaust stacks

Another angle of the engine

 

[Bandit]

The Lancaster fire up is always impressive. One I seen, three engines fired up fairly quickly, the 4th didn’t, there were flames all over the exhaust ports and appeared to be starting to spread. Some people were getting a bit excited, I remarked to my brother in law, that when it does catch, it would blow the flames all out. I got a few looks from people around me. Yes, it did that.
It’s impressive these engines running 80 +/- years after they were designed and made.
Not sure how many less gears would be used in a single row Hercules engine.

 

[PeterT]

Its peaked my interest more out of morbid curiosity

 

[Upnorth]

Yesterday morning greeted us with a blustery cold snap & skiff of white stuff on the ground. Leaf raking has been postponed. So I took a drive to Bomber Command Museum in Nanton on 'shop day'. Took my camera along & had some nice chats with a few friendly volunteers. One of the sleeve valve radials was opened up displaying its impressive gears. Practicing my photo fx mojo.

View attachment 87975

When I saw the photo I immediately knew what it was. I'm an airplane mechanic and thankfully I never had to work on one of these. If I remember correctly this style of engine was used in the Hawker sea fury. It seemed odd to me to make such a complicated engine. Depending on who you believe some claim the sea fury was the fastest single piston engine plane so maybe they were on to something.

 

[SightlessSeer]

The Lancaster fire up is always impressive. One I seen, three engines fired up fairly quickly, the 4th didn’t, there were flames all over the exhaust ports and appeared to be starting to spread. Some people were getting a bit excited, I remarked to my brother in law, that when it does catch, it would blow the flames all out. I got a few looks from people around me. Yes, it did that.
It’s impressive these engines running 80 +/- years after they were designed and made.
Not sure how many less gears would be used in a single row Hercules engine.

There is no single row version of the Hercules, but you can see how it would work from PeterT's picture above. The outer ring of gears as one gear per cylinder, with each shaft of the inner ring driving two gears of the outer ring. If you were to remove the second row you would lose half of the gears of the outer ring (7 gears total). You might also be able to eliminate the inner ring in that case, but I'm not sure if you'd have enough room to do that and still get the ratio you need.

If you look at the wikipedia page for the Bristol Perseus engine, you can see a nice picture of a cutaway engine that shows how they did it for a single row 9 cylinder engine.

When I saw the photo I immediately knew what it was. I'm an airplane mechanic and thankfully I never had to work on one of these. If I remember correctly this style of engine was used in the Hawker sea fury. It seemed odd to me to make such a complicated engine. Depending on who you believe some claim the sea fury was the fastest single piston engine plane so maybe they were on to something.

Close. The Sea Fury used a Bristol Centaurus, which is one of the next generation of sleeve valve radials from Bristol and looks quite similar. These guys were used in the Handley Page Halifax, Handley Page Hastings, the Shorts Stirling, Bristol Beaufighter, Bristol Freighter, and some early versions of the Avro Lancaster to name a few. Very successful and widely used engine. (Can you tell that I love piston aero engines 😉). The Centaurus was also a great engine, but didn't see the same widespread usage and development due to the end of the war.