Author Topic: 6/1 and 3.5/1  (Read 921 times)

mikenash

  • Hero Member
  • *****
  • Posts: 542
    • View Profile
6/1 and 3.5/1
« on: July 28, 2018, 06:41:54 AM »


Hey there experts & knowledgeable folks . . .

I have a couple of 6/1s, but also the bottom end of a 3.5/1 in the yard as well (I gave the barrel and heads to some bloke for his one)

The 3.5/1 piston is a bit lighter, I guess, so maybe the counter-weights on the wheels are different - does anyone have any experience around the interchangeability or otherwise of these, I wonder?

What started this train of thought is that the mains are probably the same bolt-hole pattern so the case could be a donor "spare", cleaner-upper for one of my 6/1s

Then I started wondering about the crank . . . am I right in thinking maybe there were two sizes journals of 3/1 big-ends and maybe (a later?) one is the same dimension as the 6/1?  Or maybe that's wishful thinking?  What excited me there is one of my 6/1s has buggered Gib keys with the heads snapped-off and is going to be challenging one day; but the 3/1 bottom end has good-looking keyways and gibs

Apart from all that, it seemed to me that if you took the 3/1 wheels off and put them on an axle in a pair of rollers and cut off the balance weights carefully until they were "neutral" balance-wise; you could just about run two flywheels on both sides of one of the 6/1s as an experiment in rotating-mass and anti-flickering and stuff like that?  (After all, the one with the buggered gib keys is never going to want to yield its flywheels so I could trim what little is left of the heads of the gibs back to nothing without being any worse off - and snug-up another pair of flywheels

Just an idle thought-train of a cold Saturday evening with the fire going and peace-and-quiet here to allow the brain to wander . . .

Cheers

EdDee

  • Hero Member
  • *****
  • Posts: 741
    • View Profile
Re: 6/1 and 3.5/1
« Reply #1 on: July 28, 2018, 07:54:01 AM »
Hey Mike...

The double flywheel setup works very well.... My APC UPS's wouldn't sync to my 12/1 when i ran below about 700 rpm.... I neutral balanced a spare set of scrap quality flywheels after a thorough checking and installed them as close to the crankcase as I could... Even  notched the heads of the inner set of gib keys to get the gap to less than half inch... The nett result is pretty much flicker free running at to below 500 rpm...And the ups's sync nicely too...

It works well indeed... when you get to below the 500 mark, it is sometimes needed to retard the injection slightly to lessen the knock and jerk... this was mainly for ups syncing. Above 500 and it makes little difference... If i remember correctly, my double wheeler is running about 550 rpm with no ill effect as yet... it pushes 4kw with reasonable ease and is pleasant sounding to boot...

Regds
Ed
12/1 750RPM/9HP Roid 5kVA- WMO Disposal/Electricity & Hot Water Gen
12/1 650RPM/8HP Roid 4.5kVa - Demon Dino
Chinese Yanmar - Silent Runner with AutoStart
Classic Komatsu 1963 Dozer/Fergusson 35 Gold Belly ...
Bikes,Cars,Gunsmithing & Paintball...Oh yes, a 5Ha open air Workshop to play in!

mikenash

  • Hero Member
  • *****
  • Posts: 542
    • View Profile
Re: 6/1 and 3.5/1
« Reply #2 on: July 28, 2018, 08:01:54 AM »
Thanks, Ed.  I have a project I'd like to run the #2 CS at about 580 rpm under about 3kW load - so that sounds hopeful.  Cheers

listard-jp2

  • Hero Member
  • *****
  • Posts: 580
    • View Profile
Re: 6/1 and 3.5/1
« Reply #3 on: July 28, 2018, 08:20:50 AM »
The 3.5/1 crank is identical to the 6/1 crank, in that it will have the 2.1/2" diameter big end journal diameter. It is the earlier 3/1 engines that are not inter-changeable as they will have the 2.1/4" journal diameter and will use the thick wall bronze backed shell bearings.
However having said that the 3/1 crankshaft is also inter-changeable with early 5/1 engines.

dieselspanner

  • Hero Member
  • *****
  • Posts: 571
    • View Profile
Re: 6/1 and 3.5/1
« Reply #4 on: July 28, 2018, 12:38:43 PM »
Hi Mike.

I have a 3.5, 6, 8/1 bitsa

The 'plate says it started life in the early '30's as a 3.5/1 hopper cooled, when it got to me it had a 6/1 top end.

Someone had poured sand in the crank case, honest!, and then it had been topped up with grease, I pulled it completely to pieces and boiled the crankcase and sundry bits in a 40 gallon barrel with a couple of kilos of caustic soda and started again.

The mains and big end were wrecked, so, having had the big end reground to suit a hugely undersized Rajkot bearing I eventually I fitted taper roller bearings, with plenty of Loctite (620, I think).

It was massively out of balance (I did the Butch bucket and string test but can't remember the details, they're on one of my previous posts, I think) so I sent off for a Rajkot 8/1 Aluminium piston. With no other counter weights it runs like a Swiss clock, well nearly!

There's a massive difference in weight between the iron and the allu pistons, again I can't remember how much, 25%?, maybe I should document more.......

Here's a link I've posted before, of it pulling 2.3 KVA

https://www.youtube.com/watch?v=js3zz6CECqY


It starts to get excitable around 675 rpm, so hopefully, when it goes into off grid duty, at around 625 rpm, in the next couple of years or so, it'll be fairly long lived.

Cheers Stef





Tighten 'til it strips, weld nut to chassis, peen stud, adjust with angle grinder.

mikenash

  • Hero Member
  • *****
  • Posts: 542
    • View Profile
Re: 6/1 and 3.5/1
« Reply #5 on: July 28, 2018, 05:09:02 PM »

Steph, thanks very much

That's an absolute beauty - especially the finish

I hadn't considered the alloy piston as an option - but I guess with such a "cold" engine their durability is good

(the 3.5/1 came with some random English truck piston fitted, and it had run on-and-off for years like that.  The guy I bought it off was in his '30s maybe, and his grandfather had fitted it "years ago")

Is there a body of experience/school of thought around the longevity of the alloy pistons?

Cheers

glort

  • Hero Member
  • *****
  • Posts: 2744
    • View Profile
Re: 6/1 and 3.5/1
« Reply #6 on: July 29, 2018, 12:23:12 AM »

Not only is the engine a beautiful runner and great to look at, that shed is fantastic.

Here in Sydney, if you had a space like that for sale, it would go for $1m  ( and I'm serious!) just because of the look of the timber and stone.
I have seen smaller places in no where near the same condition go for more in the inner city. They build cafes and trendy place to look exactly the same as that here and spend big $$ to get the look.

Stef I reckon you should clear a corner of your shed, put the engine in there, take Pictures and sell  posters or the digital files.
I'd buy one!
Better still, pay for my flight over there and I'll come do the pics for you!  :0)
Reckon I could wear a couple of bodies and lenses out in a week shooting around where you are from what you have shown here.


I have been looking for a 6/1 for so long here.  I really want a genuine engine but the ones that come up are VERY rare in 6 hp versions, ALWAYS an impractically long way off and typically overpriced.  There is a 3/1 up for sale 1000Km away for a reasonable price. Maybe I should just grab that and be happy?

ajaffa1

  • Hero Member
  • *****
  • Posts: 1198
    • View Profile
Re: 6/1 and 3.5/1
« Reply #7 on: July 29, 2018, 09:34:58 AM »
Well done Stef, what a beautiful piece of machinery, an absolute credit to you and your skill and perseverance. Loved the video well done with the star wars style intro.

Can`t wait to get back to my rebuild, I`m going to collect a new 5KVA generator head next weekend. Wish I could afford a Stamford, even second hand. I had to settle for a cheap Chinese made ST head. I`ve ordered some decent bearings for it and will true up the slip rings on the lathe before putting it into service.

I`m with Glort on the quality of out buildings in France, I`ve been planning to build in stone but finding the time and energy is a struggle, even with the stone just lying about in the fields waiting to be used.

Bob

dieselspanner

  • Hero Member
  • *****
  • Posts: 571
    • View Profile
Re: 6/1 and 3.5/1
« Reply #8 on: July 29, 2018, 09:45:15 AM »
Hi Glort

You'd love a mate of mine, Sylvain, he's the leader of the local hunt and an ultra keen wildlife photographer

https://www.google.fr/maps/uv?hl=en&pb=!1s0x12a839137cdc5c81:0xded2a09f835974bc!2m22!2m2!1i80!2i80!3m1!2i20!16m16!1b1!2m2!1m1!1e1!2m2!1m1!1e3!2m2!1m1!1e5!2m2!1m1!1e4!2m2!1m1!1e6!3m1!7e115!4shttps://lh5.googleusercontent.com/p/AF1QipO6v-UsMwbwh3xzpsnNVmr-91h2F2JhuLIlhAV8%3Dw375-h250-k-no!5ssylvane+de+payolle+-+Google+Search&imagekey=!1e10!2sAF1QipO6v-UsMwbwh3xzpsnNVmr-91h2F2JhuLIlhAV8&sa=X&ved=2ahUKEwidp4jv8sPcAhVNzRoKHSJhBesQoiowCnoECAoQCQ

A bit of a long link but I'm not too computer literate!

He spends hours up in the hills and is fascinated with all aspects of life up here , for ther first time, this year hehas an exhibition in a local bar.

For photo's of us look up Chalet Tourmalet on Booking.com, most of them were taken by my other half. For something stunning in real time, assuming decent weather conditions, check this out,

 http://picdumidi.com/fr/live-conditions/panoramique

It's about 5 miles from here, as the crow flies. it's live and sometimes the sunsets are awesome. We get all of our media via an android box and the internet, when we have guests we use it as a screensaver whilst the radio is playing through the tv.

Not sure if this counts as 'guerrilla advertising'. Ade, you can delete the first couple of paragraphs if it crosses the line!

Why not get the 3/1 and scrounge around for the bits to change the top end? At the worst way you could order a barrel, ally piston, rings ect from Rajkot, I don't know if the head is the same, I believe there's a difference in the rocker arrangement but if the cylinders fit the stud pattern then there's a good chance it will go, someone please correct me if I'm wrong.

You wouldn't damage anything, so in the - very unlikely - event of them becoming the collectors piece they deserve to be, your investment would be safe!

Cheers Stef
Tighten 'til it strips, weld nut to chassis, peen stud, adjust with angle grinder.

listard-jp2

  • Hero Member
  • *****
  • Posts: 580
    • View Profile
Re: 6/1 and 3.5/1
« Reply #9 on: July 29, 2018, 09:49:22 AM »

There's a massive difference in weight between the iron and the allu pistons, again I can't remember how much, 25%?, maybe I should document more.......


If we are talking about OEM pistons, then the weights will be:

Cast Iron piston 4.5 Kg

Aluminium piston 2.5 Kg

However from what I have seen of Indian versions of the CI piston, it's going to be slightly heavier, as the piston casting is somewhat more crude, with more material in the lower skirt area of the piston.

dieselspanner

  • Hero Member
  • *****
  • Posts: 571
    • View Profile
Re: 6/1 and 3.5/1
« Reply #10 on: July 29, 2018, 10:28:40 AM »
Hi Listard.

The flywheels would, I presume (always dangerous, a little presumption!) be weighted for the smaller piston of the 3/1 so the difference in weight (3/1 iron piston versus 6/1 ally piston) would not be quite as dramatic.

I did, whilst rebuilding my bitza, ask on here if any one knew of the difference in the cast in counterweights of the 3/1, and 6/1 (and by extension 8/1) but don't recall seeing an answer.

Cheers Stef
Tighten 'til it strips, weld nut to chassis, peen stud, adjust with angle grinder.

dieselspanner

  • Hero Member
  • *****
  • Posts: 571
    • View Profile
Re: 6/1 and 3.5/1
« Reply #11 on: July 29, 2018, 11:01:23 AM »
Hi Bob

Thanks for the 'chuck up', it's not all it seems, I made most of the standard cock ups on the way, but at least I overcame my fear of stripping down injectors and pumps!

The paint came out of aerosol cans from Lidl's (a Europe wide chain of supermarkets that have 'specials' every few weeks designed to appeal to blokes─ every thing from spray paint to chainsaw sharpeners) I always have a few cans around for brackets of what ever else I'm knocking up, and when they came aroundas I started the CS the green was almost a dead ringer so I banged a dozen into the weekly shopping trolley, much to the surprise of the Mrs!, it seems to be as durable a 'Smoothrite' and around 3 a pop. I'm down to the last can now and waiting for them to come around again.......

The Star Wars theme was my mates idea, I did read on here that the rebuild is not complete until you've put up a video, I'm a self confessed technophobe, so my mate volunteered but went a bit wild with the artistic content!!

Don't get too carried away with the 'quality' of French barns, it's got no foundations and the level is almost half a meter different from any two opposite corners, that having been said, it's stood for a couple centuries, half way up a range of mountains that are being buggered about by the tectonic plates that trying to shove Spain into France, with an earthquake every few months, it must be doing ok!

Cheers Stef
Tighten 'til it strips, weld nut to chassis, peen stud, adjust with angle grinder.

glort

  • Hero Member
  • *****
  • Posts: 2744
    • View Profile
Re: 6/1 and 3.5/1
« Reply #12 on: July 29, 2018, 12:08:50 PM »

 it's stood for a couple centuries,

That just makes my head spin right there.
I'm a dreamer and soft touch and when I hear things like that I get shivers. I wonder who built that, what did they do, what was life like then? Did the thing have planes flying over it in the war or did people Hide or shelter there? Any one famous been in it. What has been in it? Old cars and machinery, what has it seen and what stories could it tell.....
If you think my posts are long,  you should hear what goes round my head with stuff like this.

Just fascinates me.

I know my roid has a cast piston, I wonder if putting an ally one in it would make it more stable.

Is there a benefit or drawback to the heavier pistons?  Thoughts are it may give more reactive power through increased reciprocating mass, other is more wear in bearings due to higher end loads especially.

Quote
However from what I have seen of Indian versions of the CI piston, it's going to be slightly heavier, as the piston casting is somewhat more crude, with more material in the lower skirt area of the piston.

I wonder if that is why a lot of roids are out of balance?
They copied the the original flywheel size and weights ( sorta) but made the piston heavier upsetting the apple cart.

BruceM

  • Hero Member
  • *****
  • Posts: 2550
    • View Profile
Re: 6/1 and 3.5/1
« Reply #13 on: July 29, 2018, 04:55:49 PM »
The Rajkot aluminum alloy piston in my neighbor's 8/1 from DES looked like a good job of casting and machining.  If your Listeroid is a hopper it can only help, significantly.  Note that the rings aren't all the same as the cast iron piston, so plan on getting a ring set for it.


ajaffa1

  • Hero Member
  • *****
  • Posts: 1198
    • View Profile
Re: 6/1 and 3.5/1
« Reply #14 on: July 29, 2018, 10:13:32 PM »
Hey Glort, if you still want a CS have a look at this, https://www.gumtree.com.au/s-ad/petrie/other-antiques-art-collectables/lister-cs-diesel-vintage-stationary-engines-x-8-from-200-each/1191047222

Lister diesel porn, only risk one eye or you`ll go blind. Priced to sell from the look of it.

Bob