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Author Topic: Icreasing rpm of 6/1 with SOM flywheels  (Read 3566 times)

BruceM

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Icreasing rpm of 6/1 with SOM flywheels
« on: January 11, 2018, 02:35:02 AM »
I'm thinking of leaving my 6/1 on diesel for now instead of doing a propane conversion.  My new SOM wheels are 25  inch diameter so I must increase the ST-3 pulley size.  Since it worked out well for my neighbor's machine, I'm going single B belt.

At the same time, I'm considering a modest increase in RPM- say to 700 (ish) rpm.  This will benefit my air compressor which was being driven well below it's max rated speed. 

Are there any hidden surprises I should be thinking of?  My 6/1 has the iron piston.  Adjusting counterbalance weights on the new SOM wheels for a smooth run isn't be a big deal for me.

The B belt riding flat on the flywheel gives it an effectively large diameter compared to belt on the pulley vee shoulder.  So 1800 rpm at ST3 over the pulley ratio of 25.6"(SOM flywheel effective dia with B v-belt and no grooves)/10 (pulley size at ST3) gives me 1800/2.56 = 703 rpm engine speed.  A 10.25" pulley should give me 720 rpm. Either would be OK for my air compressor speed with existing 19" drive pulley.

Any helpful thoughts or gotchas I'm missing?






« Last Edit: January 11, 2018, 05:37:26 AM by BruceM »

32 coupe

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Re: Icreasing rpm of 6/1 with SOM flywheels
« Reply #1 on: January 11, 2018, 04:10:31 AM »

effective diameter.... ??

My latest creation runs b belts.
I didn't have a clue how to measure for the belt so after a couple of hours
on the net i discovered the best way to measure for a b belt is a string around
the pulleys will give a precise measurement for the belt.

B belts are measured ID.... In my case I was only looking for "close" so driven pulley
ID / OD wasn't critical.  ( my engine is rated for 1000 rpm and I was shooting for around
700) so I found a SK pulley close to the desired size on the bay and ended up at about 720.

I am sure most know this but it was something new for me.


I think "horsepoor" is running his single 6/1 at 800 rpms, if I remember correctly,
so I don't see a problem there. Especially considering you are running those "good"
flywheels and he is running the Indian junk.

I have been waiting for progress on your install. Can't wait to see some pics !

Gary





Metro 6/1 turning a ST 7.5 KW gen head
Changfa 1115 turning a ST 15 KW gen head
Ashwamegh 2/25
John Deere 110 TBL
New Holland TC 30

"I was sitting here reading this thinking what an idiot you are until I realized it was one of my earlier posts !"

BruceM

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Re: Icreasing rpm of 6/1 with SOM flywheels
« Reply #2 on: January 11, 2018, 06:01:22 AM »
A change in type and dose of thyroid medicine has perked up my brain up and I've got some help available for the next couple weeks so I'm trying to get some projects done.

 I got the steel for a new seasonal tilt PV rack delivered today, tomorrow it gets drilled and welded and some holes dug.  Five new PV panels ordered today from Sunelec.com. $0.56 per watt for some 300 watt panels they had in their Phoenix warehouse.

Yesterday we got a Qumi Q5 LED pocket projector installed to replace my old SVGA pocket projector.  I've finally got WXGA resolution at my low EMF workstation and will be able to use most software.


38ac

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Re: Icreasing rpm of 6/1 with SOM flywheels
« Reply #3 on: January 11, 2018, 12:11:22 PM »


Just some food for thought. Lister changed the piston weight to aluminum for the 800 RPM versions. A person would have to guess that they had sound reasoning and engineering behind the change. Although I have never weighed one the aluminum pistons weigh about  1/2 what the cast iron pistons weigh.  Life of your internal wear parts will be affected but to what degree I cant say.

The flywheels would be the least of my worries personally. I would not run a well worn iron piston engine at 700 RPM, however one in good shape should be OK. Keep close track of play in the big and small end bearings and if play develops quickly that will answer your questions in a definitive manner ;)
 
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dieselspanner

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Re: Icreasing rpm of 6/1 with SOM flywheels
« Reply #4 on: January 11, 2018, 03:26:07 PM »
My -nominally- 6/1 is a complete bitza.

It came with a bottom end that, according to the spec plate started life as a 3/1 hopper cooled version and the bigger top end.

With an iron piston it leaped about spectacularly, whether the flywheels for the smaller engine have smaller built in counter weights I don't know but changing to an aluminium one made a vast difference, no balancing required to run at 620 rpm.

Hopefully a 6/1's flywheels won't be over weighted with the lighter piston.

Does anyone know if the various models had vastly different counter weights?

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

dieselgman

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Re: Icreasing rpm of 6/1 with SOM flywheels
« Reply #5 on: January 11, 2018, 03:41:42 PM »
Pretty sure the 3/1 flywheels will be different (lighter) than the 6/1. I have some here and will compare side-by-side when I get a chance. It seems that the smaller cast iron 3/1 piston might be closer to the weight of the 8/1 alloy piston. Lister had Many changes in flywheel designs over the years.

dieselgman
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BruceM

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Re: Icreasing rpm of 6/1 with SOM flywheels
« Reply #6 on: January 11, 2018, 03:57:44 PM »
Thanks for the good thoughts, 38AC. My 6/1 has about 3000 hrs on it so not pushing the rpm on the iron piston is probably best.  I'll determine the effective pulley size of the flywheel by measuring rpm ratio of my neighbor's 8/1 b-belt setup.  9.75" pulley on the generator should be close but I want to double check and only buy one QD hub pulley.






38ac

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Re: Icreasing rpm of 6/1 with SOM flywheels
« Reply #7 on: January 11, 2018, 07:40:30 PM »
Be sure to watch ebay for the hub and pulley they are often found on that venue for a song
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32 coupe

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Re: Icreasing rpm of 6/1 with SOM flywheels
« Reply #8 on: January 11, 2018, 09:57:33 PM »

Those darn pulleys are expensive.

I bought my 8.5 qd on the bay for $20 with $10 shipping. It was NOS.

I thought that was a bargin.


Metro 6/1 turning a ST 7.5 KW gen head
Changfa 1115 turning a ST 15 KW gen head
Ashwamegh 2/25
John Deere 110 TBL
New Holland TC 30

"I was sitting here reading this thinking what an idiot you are until I realized it was one of my earlier posts !"

BruceM

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Re: Icreasing rpm of 6/1 with SOM flywheels
« Reply #9 on: January 12, 2018, 12:00:30 AM »
I can reuse the existing QD hub so I will be out just for the pulley.  $35 at Zorro , but I'll try to find a bargain somewhere.  Expensive enough to want to get the size just right!

We got the new 5 panel rack put together and painted today.  Monday it will be hole digging and concrete for the support posts.

About $320 for steel angle and square tube and hardware for one 200 inch long rack. Upright posts are angle iron, 3x3x1/4".  I'm going to revise and remount the old 5 (175 W) panel rack with my new design which allows a one man seasonal tilt change.  The old panel rack was a tough lift and hold for even 2 guys.

« Last Edit: January 12, 2018, 12:11:28 AM by BruceM »

dieselspanner

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Re: Icreasing rpm of 6/1 with SOM flywheels
« Reply #10 on: January 12, 2018, 06:46:10 AM »
Hi 38ac &co

Small question, is the QD hub and fitting you are refering to in 'American' the same thing as I call a Taper Lock in 'English'?

Looking up QD hub only gets me wheels for my old BSA A65, it already has some of those!

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

dieselspanner

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Re: Icreasing rpm of 6/1 with SOM flywheels
« Reply #11 on: January 12, 2018, 06:47:18 AM »
Hi 38ac &co

Small question, is the QD hub and fitting you are refering to in 'American' the same thing as I call a Taper Lock in 'English'?

Looking up QD hub only gets me wheels for my old BSA A65, it already has some of those!

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

dieselgman

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Re: Icreasing rpm of 6/1 with SOM flywheels
« Reply #12 on: January 12, 2018, 10:09:20 AM »
QD refers to quick disconnect, taper lock is another variation.

dieselgman
ALL Things Lister/Petter - Americas
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38ac

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Re: Icreasing rpm of 6/1 with SOM flywheels
« Reply #13 on: January 12, 2018, 01:44:48 PM »
As Gary said what most people refer to as a taper lock is actually a QD type bushing

This is a QD


This is a taper lock
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listard-jp2

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Re: Icreasing rpm of 6/1 with SOM flywheels
« Reply #14 on: January 12, 2018, 06:02:54 PM »
Although I have never weighed one the aluminum pistons weigh about  1/2 what the cast iron pistons weigh.

Approximate weights (using OEM parts) Cast Iron 4.5Kg, Aluminium 2.5Kg. Indian cast Iron pistons are heavier when compared to an OEM item due to the more cruder nature of the casting, and also the wall thickness of the piston been greater in the skirt area of the casting.