Are my flywheels typical?

[Barenburg]

I'm new here so Hello to everyone.

I have a 6/1 clone I've considered a Kit Engine for a while and have just found time to work on the thing.

I've stripped the castings down, and painted everything.  During the Flywheel inspection I was not impressed by the quality of the casting.  They do look good now with flash, sand and mis-matches ground out. 

In my effort to match them I made a 2" shaft with ball bearings and used that as an easy way to use the "string and bucket method" to match them.  Interestingly enough the key slots are in the correct location compared to the geometry of the wheel, however the both wheels settle to an awkward position.

I'm not sure if I figured out how to link a picture but the settle with the counterweight about 10 degrees from center.  It takes about 7 oz of lead at what should be the three o'clock position to get them close.

Other than that they ring OK and are within about 2oz of each other.  It appears to be a combination of mold mismatch and porousity in the castings.  As bad as they are, they are remarkably consistent.

Thanks,  Bill

[dieselgman]

I do not see any pictures, but by your description would certainly be considered "typical".

Sounds like you are on the right track to getting them checked out and properly balanced.

dieselgman

[BruceM]

Welcome, Bill
Sounds like you're doing a first class rebuild. Bravo.

+1  on Gary's comment:  7 oz to correct  a 10 degree error is normal, and consistency within 2 oz is exceptional.

Once you do your final  balancing under load, you'll appreciate 38ac's  method greatly, as I did.  Fore and aft movement of the head means you need to reduce counterbalance, up and down means add more counterbalance. In either case, 2oz to each wheel is a useful small increment.  Don't be shocked if it needs up to 16 oz per wheel.

Check that cam shaft for straightness and check the lobe timing too.  It's easiest to check lobe timing before adding the connecting rod, piston and cylinder; if you do find the wildly off blooper you're ready to correct the offending lobe without a lot of extra work and wasted time. A dial gauge on the valve lifters, TDC and BDC on your flywheel relative to the rack closer bolt center is all you need (plus a metric tape measure).

Best Wishes,
Bruce

[38ac]

Sounds like you have a typical set of Indian 'wheels to me.  I am also in the middle of adjusting a set of 8/1 type disk flywheels for a customer project.
 Its real important that the heavy spot in in the exactly opposite the crankshaft throw or weird things happen when you are trying to settle the engine down. Since the Indians rarely get the keyway in the exact right place a person  cannot rely upon the spokes or shape of the flywheel to get the heavy spot in the right place.  The procedure to get it right is a bit involved to write up but in practice doesn't take long and the results are quite satisfying. Here is how I do it. Some pictures might be helpful, let me know if you'd like them?
 #1 You need to have a a DEAD ON  TDC mark.
You do this by installing a piston stop. This need not be fancy but needs offer repeatable results.  I use a cross bar puller and the long head studs. You can put a 3/8" nut on top of the piston where it wont hit the valves or swirl chamber and bolt the head back on with a couple nuts. You also need a steady pointer. The fuel pump bolts and governor pivot bolt are handy places to a pointer. Install both flywheels and insert the Gibb keys far enough that they dont move.  Now turn the engine unit it hits your stop and mark the flywheel next to your pointer. Then turn it the other way until it hits and mark the flywheel once more.  Halfway between your marks is exactly TDC.  If using a nut or other somewhat flimsy stop be sure to turn the crank and check several times to be sure your result is repeatable.  Mark TDC and remove your stop.

#2  Place marks on the flywheels that are inline with the crank throw.
  This is easiest done with the engine sitting on the floor. It can be on a cart or skid but the base must be near level.  If you happen to have a drywall square it works great, if not you need a couple  of 4 foot 2x4 s and a framing square. You screw the 2x4s together making a  big "t" shaped square. If you happen to have half a sheet of plywood that was cut squarely it would also do the same thing. Place the engine at TDC and put your square on the floor, against the crankshaft  and up next to the flywheel and place a mark the width of the rim both on top and the bottom of the flywheel.  Now move it to the other side of the crankshaft and do the same thing. You now  have marks roughly 2" apart on opposite sides of the crankshaft that are in exact line with the crankshaft throw. Replete on the other flywheel.  Next place strips of masking tape on your marks and spray paint the area between the tape with easily seen paint, I use white. If your engine is painted and you dont wish to redo it then tape the entire area between the marks.
#3 now remove the flywheels and put them back on your balance stand then stand back and look at the areas you painted on the flywheels, they must be vertical. If not you must  add weight, grind or drill to correct. Again pay no attention to to the orientation of the spokes as they are irrelevant.
#4 Now you hang the can of weights and equalize the offset weight in both flywheels.
#5 Preform running tests remembering that all weight added or subtracted must be in line with or opposite the crank throw and NEVER anywhere else.

[BruceM]

Thanks for this update, Butch.  Not trusting the crankshaft keyway location is something I didn't understand before.

[38ac]

Some pics to make it easier to digest.
This is my preferred design easy to make pointer. Remove and drill the governor pivot bolt about 3/8" deep with a #7 bit. Do not go too deep as it will weaken the shank. Then tap with a 1/4 -20 tap, you will need a bottom tap for this due to the shallow hole. Next you need a 1/4" cap screw long enough that it has an unthreaded portion. Cut the threads so only a 2-3 remain.  then cut the head and shank so what remains looks like the picture. Round it some and install .  Once you find TDC  Mark it at the pointer with a square and marker then stamp it in the flywheel with a chisel so it is permanent. The other mark is 20 degrees prior to TDC and used for timing the start of fuel injection.


This is what I was talking about on how to mark the flywheels. The engine does not need to be leveled however the bottom of the square must be in the same plane as the base. mark each side with a marker then fill in the middle so it is easy to see. In the picture it is evident that the key way is not perfectly aligned with the opening on this 8/1 flywheel. Lots of grinding was required to get the marks to sit straight up and down on the stand.  This is why step one is mandatory to achieve good balance and one of the things that makes the guess and place methods so hard to achieve good results with.

[mikenash]

Sounds like you have a typical set of Indian 'wheels to me.  I am also in the middle of adjusting a set of 8/1 type disk flywheels for a customer project.
 Its real important that the heavy spot in in the exactly opposite the crankshaft throw or weird things happen when you are trying to settle the engine down. Since the Indians rarely get the keyway in the exact right place a person  cannot rely upon the spokes or shape of the flywheel to get the heavy spot in the right place.  The procedure to get it right is a bit involved to write up but in practice doesn't take long and the results are quite satisfying. Here is how I do it. Some pictures might be helpful, let me know if you'd like them?
 #1 You need to have a a DEAD ON  TDC mark.
You do this by installing a piston stop. This need not be fancy but needs offer repeatable results.  I use a cross bar puller and the long head studs. You can put a 3/8" nut on top of the piston where it wont hit the valves or swirl chamber and bolt the head back on with a couple nuts. You also need a steady pointer. The fuel pump bolts and governor pivot bolt are handy places to a pointer. Install both flywheels and insert the Gibb keys far enough that they dont move.  Now turn the engine unit it hits your stop and mark the flywheel next to your pointer. Then turn it the other way until it hits and mark the flywheel once more.  Halfway between your marks is exactly TDC.  If using a nut or other somewhat flimsy stop be sure to turn the crank and check several times to be sure your result is repeatable.  Mark TDC and remove your stop.

Hey Butch, excuse a stupid question - but this works on the assumption that the keyways cut in the crankshafts are at zero degrees.  Is this reliably the case?  Cheers

#2  Place marks on the flywheels that are inline with the crank throw.
  This is easiest done with the engine sitting on the floor. It can be on a cart or skid but the base must be near level.  If you happen to have a drywall square it works great, if not you need a couple  of 4 foot 2x4 s and a framing square. You screw the 2x4s together making a  big "t" shaped square. If you happen to have half a sheet of plywood that was cut squarely it would also do the same thing. Place the engine at TDC and put your square on the floor, against the crankshaft  and up next to the flywheel and place a mark the width of the rim both on top and the bottom of the flywheel.  Now move it to the other side of the crankshaft and do the same thing. You now  have marks roughly 2" apart on opposite sides of the crankshaft that are in exact line with the crankshaft throw. Replete on the other flywheel.  Next place strips of masking tape on your marks and spray paint the area between the tape with easily seen paint, I use white. If your engine is painted and you dont wish to redo it then tape the entire area between the marks.
#3 now remove the flywheels and put them back on your balance stand then stand back and look at the areas you painted on the flywheels, they must be vertical. If not you must  add weight, grind or drill to correct. Again pay no attention to to the orientation of the spokes as they are irrelevant.
#4 Now you hang the can of weights and equalize the offset weight in both flywheels.
#5 Preform running tests remembering that all weight added or subtracted must be in line with or opposite the crank throw and NEVER anywhere else.

[dieselgman]

I have not seen a faulty crankshaft keyway (off of 0 degrees) before... this does not by any means indicate that it does not happen.

It is likely a safe assumption to make, that ALL assembly parameters could be questioned. Perhaps they should be? I don't know the exact machining order of operations for those cranks, but if someone set up the equipment in less than a fully accurate manner... all bets are off. Butch's marking method would certainly be dead-on accurate for TDC on the conrod throw, at least that would NOT be dependent on keyway placement.

I also know that the crank pinion gears are pressed on the shafts without any alignment keyway... that would be another place where typical Indian QC could easily fall short or fail. Lister used, and uses, very elaborate and precise jigs to assemble things like cam gears (and crank pinions) that also lack any alignment reference points. These things are at least in part dependent upon a highly skilled and attentive operator.

dieselgman

[BruceM]

Simple enough to locate the proper counterbalance location independent of crank keyway, now that Butch has shown us how. Best to assume nothing from Rajkot and then be pleased; they do get many things right, you just can't predict which ones.

[38ac]

Gary, The way the crankshafts are made and assuming how they are held for machine work the crank key is easy to get in the correct place, Not so with the flywheels. I have never seen a crankshaft with a keyway in the wrong place  but have only seen a couple flywheels that did have  them in the correct place. None the less when installed and marked on the engine it matters not other than the grinding one must do to get the offset weight in the correct relationship to the crank pin.  Building 'roids would be boring if there wasn't for corrective work to do, LOL

[Barenburg]

Thanks for the warm welcome!

I don't do much social media. How are you hosting pictures so the show up? I tried putting picture on Google Share, but I've obviously done something wrong

TY

[cujet]

Hi there!

I balance helicopters for a living, the lister is child's play. I understand single cylinder engine balance quite well. I've come to the conclusion that the balance of a single cylinder engine really needs to be done while running. While not required, it might be slightly better to do it at partial load. If both flywheels are consistently made, they then any unbalance will offset each other. As they are mounted opposed.

Install 'em, run the engine and then balance it, via the methods contained in some threads/posts on this forum. If you balance the flywheels first, you have not accomplished anything helpful on a single.

Briefly: A Lister's single piston's inertia can be offset by a 100% counterweight. However, that full counterweight will then cause horizontal "shuffle", as there is no horizontal opposing force to that counterweight. Picture the counterweight at the same level as the crank, it's inertia will pull the engine that direction!

Soooooo, a counterweight is generally "about" 50% of the reciprocating mass. For many single cylinder engines, a 53% "balance factor" works well. This results in an engine that has equal up/down and fore/aft vibrations. And done correctly, is generally considered comfortably smooth.

A single will never be vibration free without some form of trickery! (for example, a single or better yet, pair of counter-rotating balance shafts) There are other ways to make a single mostly vibration free. None of these methods apply to us, ignore them.

[cujet]

When we dynamically balance a conventional single, we mount accelerometers vertically and horizontally. In relation to the cylinder. We then compare the readings between the two. The goal is simple, match as closely as possible the two readings. We find that overall vibration, measured in IPS (inches per second) decreases significantly when the two are matched closely.

It is typical to find many production engines underbalanced, as weight is expensive and/or takes up room. Single cylinder engines from lawn mowers, to dirt bikes and listers all suffer from production quality issues. Most are assembled from parts within a set of specifications or limitations. Very, very few are actually balanced dynamically prior to leaving the factory.

[mikenash]

Hi there!

I balance helicopters for a living, the lister is child's play. I understand single cylinder engine balance quite well. I've come to the conclusion that the balance of a single cylinder engine really needs to be done while running. While not required, it might be slightly better to do it at partial load. If both flywheels are consistently made, they then any unbalance will offset each other. As they are mounted opposed.

Install 'em, run the engine and then balance it, via the methods contained in some threads/posts on this forum. If you balance the flywheels first, you have not accomplished anything helpful on a single.

Briefly: A Lister's single piston's inertia can be offset by a 100% counterweight. However, that full counterweight will then cause horizontal "shuffle", as there is no horizontal opposing force to that counterweight. Picture the counterweight at the same level as the crank, it's inertia will pull the engine that direction!

Soooooo, a counterweight is generally "about" 50% of the reciprocating mass. For many single cylinder engines, a 53% "balance factor" works well. This results in an engine that has equal up/down and fore/aft vibrations. And done correctly, is generally considered comfortably smooth.

A single will never be vibration free without some form of trickery! (for example, a single or better yet, pair of counter-rotating balance shafts) There are other ways to make a single mostly vibration free. None of these methods apply to us, ignore them.

I predict there will be discussion on this question . . .

[Barenburg]

OK, another attempt to add the pictures after 7oz of weights added at about 3 o'clock

I guess you can teach old dog new tricks...........