Coming back after 2-1/2 years

[Lloyd-ss]

Things seldom turn out like we plan, but after two and a half years away from the HMEM forum, it looks like the opportunity to try building a diesel is finally back on. In the first post of the diesel project
https://www.homemodelenginemachinis...-x-66-56-4cc-4-stroke-injector-details.31110/it looks like I wanted to make a 2 stroke, then axed that idea and was going to try a 4 stroke instead. Then a month ago, I got to thinking about diesels again, and in particular, 2 strokes. At that time I had not re-read my post number one. But I was looking at the Detroit Diesel 2 stroke series with the roots blower and got the bug to give it a try. So, I have come back full circle. The 2 stroke is on again, for better or for worse. Hard headed or not.
My interest in diesels goes back to my early 20's when i was working construction and ran across a couple of unusual diesel situations. There was a mechanic for the construction company who had the gift. He could keep just about anything running. I remember he was trying to start a stubborn bull dozer and him yelling at the guy helping him, "No, put the gasoline on a rag and hold it over the air cleaner, don't pour the gas into the cleaner!" Luckily, the engine didn't explode.
They had a diesel powered pile driver for big timber pilings. It was like an inverted cylinder with a solid steel piston about 8" in diameter and 4 feet long fitted into it. To start the hammer, a cable lifted the piston, and then dropped it back into the cylinder with a tiny squirt of diesel fuel at the bottom.If it fired, the piston jumped back up under its own power, and then fell back down as a squirt of diesel was automatically injected to keep the cycle going. Brilliant in its simplicity!
Then, at a job in the Norfolk (VA, USA) shipyard, when ships were in drydock, they hooked up these old 2-stroke diesel generators, salvaged from ships, to power the ships during overhaul. The diesels were blown 2-strokes about 8 feet tall and long, and 3 feet wide. They ran 24 hours a day, sounding like an old Greyhound bus lumbering along. Fond memories.
So here we go on an attempt at continuing attempt number one.... with changes.
Thank you for providing this forum and sharing your knowledge.
Lloyd Sikes

 

[stevehuckss396]

Welcome back!

 

[johnmcc69]

As Steve said, Welcome back!

Great stories! hope to hear more about your endeavors!

John

 

[Lloyd-ss]

Thanks guys. Hard core craftsman hang out here! I am in awe at what the members do. Outside summertime work still takes most of my energy, but I still have some to spare.
Lloyd

 

[Thommo]

Hi Lloyd, I’m very much looking forward to seeing a blown 2 stroke diesel. Awesome!!

 

[Lloyd-ss]

Hi Lloyd, I’m very much looking forward to seeing a blown 2 stroke diesel. Awesome!!

Ha ha, yes. I anticipate making lots of scrap parts on the way to (hopefully, fingers crossed) maybe some success. There is a big learning curve and a long way to go.

 

[Nikhil Bhale]

Hi,
Welcome back to the forum.
I like 2 stroke engines.
Being a marine engineer working on ships, I work with them all the time.
With bore of 60 cms to 100 cms (about 24" to 40") and power of 30000kw to 75000 kw ( 50000- 100000 bhp) these are different beasts altogether.

Regards
Nikhil

 

[Lloyd-ss]

Nikhil,
I LOVE the huge marine diesels, but have never been in the engine room with a modern 2 stroke diesel.
The design for my 2 stroke diesel is still very fluid. I am starting with the easier parts first. The flywheel came out nicely. And I hope to test the Roots blower in the next few days. I really like the sound of a low speed engine, like the marine engines. I am still learning and having trouble finding out how the basic design of the engine influences the engine speed. I know that a longer stroke will help keep the RPM low. But what else can be done during the design phase? And I also have some doubts that the engine will work at all, but I have time to try many times. The plan so far is a 33mm bore x 66mm stroke with a crosshead slide. I had originally planned on a horizontal arrangement, but now I am thinking vertical, because the reaction forces to the foundation would be more manageable. Do you have any suggestions?
Thank you,
Lloyd

 

[Steamchick]

Tell us more, Lloyd, 'n all. Great tales of engines!
K2

 

[Thommo]

Hi,
Welcome back to the forum.
I like 2 stroke engines.
Being a marine engineer working on ships, I work with them all the time.
With bore of 60 cms to 100 cms (about 24" to 40") and power of 30000kw to 75000 kw ( 50000- 100000 bhp) these are different beasts altogether.

Regards
Nikhil

Hi Nikhil, I was a marine engineer in the navy for many years and whilst I was primarily on steam powered ships I did spend a lot of time on largish Detroit generator engines, but my favourite diesels were a couple of 6 cylinder Scott Sulzer 6 cylinders on one of our supply ships. I used to love reversing the cams on the old girls. I remember standing on the pistons while we scrubbed the bores with floor sized steel brushes as the pistons were raised and lowered lol.

 

[Nikhil Bhale]

Nikhil,
I LOVE the huge marine diesels, but have never been in the engine room with a modern 2 stroke diesel.
The design for my 2 stroke diesel is still very fluid. I am starting with the easier parts first. The flywheel came out nicely. And I hope to test the Roots blower in the next few days. I really like the sound of a low speed engine, like the marine engines. I am still learning and having trouble finding out how the basic design of the engine influences the engine speed. I know that a longer stroke will help keep the RPM low. But what else can be done during the design phase? And I also have some doubts that the engine will work at all, but I have time to try many times. The plan so far is a 33mm bore x 66mm stroke with a crosshead slide. I had originally planned on a horizontal arrangement, but now I am thinking vertical, because the reaction forces to the foundation would be more manageable. Do you have any suggestions?
Thank you,
Lloyd

Lloyd,

I appreciate the vote of confidence in me. I am a "maintenance engineer" who don't have any say in the design.
I can give you some pointers.
Modern marine engines are uniflow design with scavenge ports and a single exhaust valve.
They have bore to stroke ratio of 3-4. This gives more efficiency, helps in burning heavy fuel and have lower rpm of 70-110.
They have crosshead design and are vertically oriented. Same as you have in mind.
I will suggest to get a look at some proven 2 stroke model engine plan and tinker with it according to your needs.

Regards
Nikhil

 

[Nikhil Bhale]

Hi Nikhil, I was a marine engineer in the navy for many years and whilst I was primarily on steam powered ships I did spend a lot of time on largish Detroit generator engines, but my favourite diesels were a couple of 6 cylinder Scott Sulzer 6 cylinders on one of our supply ships. I used to love reversing the cams on the old girls. I remember standing on the pistons while we scrubbed the bores with floor sized steel brushes as the pistons were raised and lowered lol.

Hi Thommo,

And to go inside the scavenge spaces for cleaning it. Or to go inside the crankcase to check the bearing clearance.

Regards
Nikhil

 

[Lloyd-ss]

Tell us more, Lloyd, 'n all. Great tales of engines!
K2

Wow, the enthusiasm on this forum is self perpetuating! I love it! Totally geek stuff.

My first engine experience happened when I was 8 or 10. An older man (I would call him younger now, LOL) who lived down the street did a lot of small engine repair. He gave a pair of worn out engines to me and my brother (who was a year and a half younger than me) to do whatever we wanted to do. Very cool! I can almost picture it now: sockets and wrenches and screwdrivers taking mine all apart. The bearing journals were still all shiny and oily. The crank and conn rod were particularly intriguing. I think I checked out an Audels small engine book from the library. The covers of the books were always orange and black. Learning about the valves and the 4 stroke cycle. So in a matter of a few days mine was all apart and I understood how it worked. My future was cast in stone.
My brother, on the other hand, got frustrated with his engine, and after about 30 minutes, got our dad's biggest ball peen hammer and smashed it to pieces. Oh well. But I did learn from his engine that the wall thickness on the engine castings was only about a eight of an inch think. There is ALWAYS something to learn.
Lloyd

 

[Lloyd-ss]

Hi Nikhil and Thommo,
Thanks for you thoughts and insight and stories.
Ships are tying us all together. I worked for Sperry Marine where we designed and built and serviced marine navigation equipment, including the inertial navigation systems, from spinning mass to ring laser to fiber optic. Cool stuff and it made the job exciting.

The huge marine diesels that are connected to the props without gear boxes blow my mind. And changing the direction of engine rotation to go into reverse, wow. Thommo, is that what you were talking about with reversing the cams?

So much to learn!
Lloyd

 

[deverett]

A couple of old war stories:
I started life in the British merchant navy and as a deck cadet, we were expected to know a bit of what happened below decks. So, into the crankcase of the Doxford engine I was sent to undo the big end bolts and nuts using a 7lb short handled sledge. The engineers then scraped the new big end bearings and I then had to knock up the bolts for them so that they could take 'leads'. The bolts were hammered up until they rang - no torque wrenches in them dark days. They were then undone and the leads measured. This was done a couple of times until the clearance was satisfactory. The engineer would give the final knock to the bolts/nuts.
Not all vessels had gyro compasses. The modern ones that did were equipped with Sperry Mk.XIV gyros. These had a 56lb wheel and spun up to 7000 rpm (I think). The transmission was done by trolley and contactor and the outer frame used to see-saw backwards and forwards clacking away while the compass stabilised.

Dave
The Emerald Isle

 

[Lloyd-ss]

A couple of old war stories:
I started life in the British merchant navy and as a deck cadet, we were expected to know a bit of what happened below decks. So, into the crankcase of the Doxford engine I was sent to undo the big end bolts and nuts using a 7lb short handled sledge. The engineers then scraped the new big end bearings and I then had to knock up the bolts for them so that they could take 'leads'. The bolts were hammered up until they rang - no torque wrenches in them dark days. They were then undone and the leads measured. This was done a couple of times until the clearance was satisfactory. The engineer would give the final knock to the bolts/nuts.
Not all vessels had gyro compasses. The modern ones that did were equipped with Sperry Mk.XIV gyros. These had a 56lb wheel and spun up to 7000 rpm (I think). The transmission was done by trolley and contactor and the outer frame used to see-saw backwards and forwards clacking away while the compass stabilised.

Dave
The Emerald Isle

Dave, great story about precision torquing of bolts. No wasting time with strain gauges or measuring bolt stretch, ha ha. I guess that almost everything was over-designed/over-built with plenty of safety margin back then.

Sperry Mk 14, huh? I am by no means young, but when I retired about 7 years ago, we were building the Mk49. There is a characteristic of gyroscopes that I wasn't aware of until I took a course in navigation theory at work (geek fun). That fact is that when a gyroscope (not a gyro compass) is spun up to speed, it always wants to point to the same place in the universe. Not north or south or anywhere in particular on the planet. That is why those old gyro compasses were so huge. There was al sorts of magic performed to get them to actually point north on the planet, instead of some finite direction in the universe. Maybe the Starship Enterprise uses a gyroscope, LOL.

We had the good fortune to visit your beautiful country a few years ago. My wife's grandmother was born in County Fermanagh but emigrated to the US with her mother and sisters when very young. My wife wanted to try and find where they had lived, and she had found some family graves at the Catholic church on a previous visit. This time, with the help of some wonderful people in the area, and a genealogy expert from Enniskillen Castle, she was successful at finding where the home had been. Beautiful area on a beautiful day. Quite an emotional experience.

(I hope this isn't straying too far from the intent of the introduction forum.)
Lloyd

 

[Steamchick]

Keep writing (Lloyd, 'n all)... it is all part of the pallet of colour that enrishes our lives...
K2