Nemett Lynx 15 cc 4 Stroke I/C Petrol Engine

[gus]

Simple looking aluminium piston took 3 hours to complete in the morning and another 2 hours to fit into crankcase and cylinder assembly.

Honing done with brake drum cylinder hone and Makita Cordless drill.
At last the rotating and reciprocating portions done and Gus could spin the crankshaft with the piston moving up and down.Piston rings will get done tomorrow. And from here will be moving upwards into valves and cams.

Took darling boss out for Indonesian Medan Food. See food and piston in the cylinder sleeve.
We had Rendang Beef,Rendang Chicken, Soto Ayam Soup and Deep Fried Pork Belly.Good eating but health hazard.

 

[BaronJ]

Hi Gus,

Coming along nicely ! I have one of those hones. Where do you get your spare stones from. The ones supplied with mine didn't last ten minutes. They wore away at one end despite being full in the bore.

I got another wiper motor this morning. Getting on with MK2 !

 

[Swifty]

Baron, you might have difficulty getting replacement stones, the hones are virtually a throw away item. Despite this, you could try any good Toolmakers supply shop, they should have a good range of polishing stones, usually in 6" lengths.

Paul.

 

[gus]

Had to make new con-rod. After fitting in con-rod with piston on to the crankshaft into crankcase, I had difficulty cranking over.
During the process of pressing in needle bearing on to big end,same got mis-aligned and would respond to re-alignement.
Make new rod. Four jaw chuck did not have the capacity to hold off-set rod blank. Tried a very odd way of job holding with the three jaw chuck.Surprise.Surprise.It worked. Re-discover I could reduce blank thickness by turning on the lathe and much faster than end milling.

 

[bmac2]

Hi Gus.
Was reading Swifty’s build and you had said you had no way of measuring accurately on the Z axis on your mill. This is the cheap, quick and dirty method I’ve been using on my mill almost since I got it home. It’s just a clamp that fits on the column and holds a dial indicator. No fancy angles just cut to fit and bolted tougher out of whatever you have around. You should be able to rig up something so it can read off the quill. The bolt sticking out of the bottom is so I don’t smash into the indicator when I move the head up. Best of all it’s dead accurate and . . . . . . . NO BATTERIES Thm:

 

[gus]

Hi Gus.
Was reading Swifty’s build and you had said you had no way of measuring accurately on the Z axis on your mill. This is the cheap, quick and dirty method I’ve been using on my mill almost since I got it home. It’s just a clamp that fits on the column and holds a dial indicator. No fancy angles just cut to fit and bolted tougher out of whatever you have around. You should be able to rig up something so it can read off the quill. The bolt sticking out of the bottom is so I don’t smash into the indicator when I move the head up. Best of all it’s dead accurate and . . . . . . . NO BATTERIES Thm:

Great idea. But have modify to suit round column pillar.

 

[gus]

The Timing Gears and belts came in. Will be busy over next two weeks. But I thought I am taking my sweet time so why rush.
Hi Paul.
Its fishing time today. Not too bad but I lost three with 20 lb line breaking off. This gentleman nearly had a heart attack with this
Diamond Trevally.Fishing again tomorrow.

 

[BaronJ]

Baron, you might have difficulty getting replacement stones, the hones are virtually a throw away item. Despite this, you could try any good Toolmakers supply shop, they should have a good range of polishing stones, usually in 6" lengths.

Paul.

Hi Paul,

That is what I suspected may be the case. I don't think the ones that I bought were very good at all !

Your right its in the scrap bin they go...

Thanks:

 

[BaronJ]

Hi Gus,

Very pretty ! I mean the engine, not the fish

 

[gus]

Timing Gears bored,reamed and mounted. Spacers on Crankshaft done. Will assemble tomorrow into Bearing Housing.
New Con-Rod done. No more obstruction when I crank shaft and piston.
Gus down with a very mild flu.Recovering fast.No worry.

 

[BaronJ]

Timing Gears bored,reamed and mounted. Spacers on Crankshaft done. Will assemble tomorrow into Bearing Housing.
New Con-Rod done. No more obstruction when I crank shaft and piston.
Gus down with a very mild flu.Recovering fast.No worry.

Sorry to hear that you're not so well. A glass or three of the good stuff will help with that.

That engine cylinder looks very mean with that lot up top. I assume that is the drive for the camshaft. Looking forward to seeing it running.

 

[gus]

Sorry to hear that you're not so well. A glass or three of the good stuff will help with that.

That engine cylinder looks very mean with that lot up top. I assume that is the drive for the camshaft. Looking forward to seeing it running.

Have a problem drinking. Not enough.I can't sleep. Just enough.I fall asleep and wake up at 3 am.Drink too much,I can't sleep. But two glasses of Red works.
Will do that tonite.
Did some improvement on the idler pulley bolt. Machine a brass hex bolt to improve aesthetic.


Not a very productive morning in term of work quantum.
Just discovered how to fit in timing belt. Both have to be pulled together.

Timing system fitted in. ;D

Moving on to piston rings. Reading up now and jotting down work instructions and make sure I have the required tools/cutters to do a good job once and not two/three times.

 

[gus]

Breather line fittings done and figuring out how to connect and look good. May have to do it my way to make easy/direct/good looking. Been a long long not done control piping. I have a DIY tube bender made 10 years ago.

There are some forum members omitting the breather line which is required to oil cams,cam-shaft and tappets. Crankcase pulsation is just excessive and must be balanced out.

 

[Swifty]

Hi Gus, where did you get the fittings for the breather, are they a standard hydraulic fitting?
I assembled the rings to my piston tonight, and fitted it into the cylinder, lots of pressure when I cover the end with my hand.

Paul.

 

[gus]

Hi Gus, where did you get the fittings for the breather, are they a standard hydraulic fitting?
I assembled the rings to my piston tonight, and fitted it into the cylinder, lots of pressure when I cover the end with my hand.

Paul.

They were DIY from samples but modified. The Cap-Nuts were 10mm Brass Hex with M8 and the nipple M5 make. I still had some olive sleeves left.
See fotos-------DIY tube end fittings and engine breather tubing done. Too many bends will redo my way with one clean bend. May be running short of olives. No Problem.DIY olives. Tube bender is also DIY.

Not happy with too many bends. Redo breather tube to 2 bends that is a big bend and small bend. Now breather tube looks plain and simple and was easy to bend with plenty of lee-way to play with and then lock on.



Lotsa pressure .Thats good and this is because piston/rings and cylinder seating
well.

 

[gus]

Well. The mild flu is about dead and gone and Gus still alive. Went on at 4 pm to cut piston rings.
Since I have 6------20 mm twist drills,bored ID with 6mm pilot hole and from with incremental of 2mm to 20 mm with 3 mm
to hit 23mm I.D.
See fotos. My first C.I. Ring. SWMBO boss just called,''Gus take a rest.''


Paul,
1. Were you using a MT3 shank to split rings. Looks like I have to buy or DIY same.
2. Please advise OD of heat-treatment holding device. I am worried about deformation and ring
OD gone oval.

Went out to buy 4 mm OD copper tubing and also to get my ''71' young system tuned up after
the flu.Good reason why I could cut one blank ring.

 

[Swifty]

Hi Gus, the redone breather tube looks great. I used a 3MT shank to split the rings, although you could turn up a tapered shaft to split them on, just polish the surface so there are no snags, I used some 1" OD copper tube to push the rings evenly.

The heat treatment fixture had a diameter of 24mm to hold the rings open, this worked well, the rings fit really well. When I hold my palm over the cylinder and move the piston, there is lots of pressure.

Not much done the last couple of days, I just made the tensioner pully. I went flyfishing again today to the same place as last week, best I could do was to lose a fish when the fly broke off the line, I always check my knots carefully, but it broke anyway.

Paul.

 

[gus]

Good to take break and recharge batteries. SWMBO suggest I take a break from fishing to fully recover. No fishing this Saturday and Sunday.
Its Neap Tide and fish won't bite.S$45 Diesel x two days saved.
Will make the 3MT if I have the material.
Have a good fly-fishing trip.

 

[gus]

Best to use Malcom's method of mounting piston ring blanks on a no. 3 MT mandrel to split same. I have no 3MT sleeve or shank. Made a short mandrel using recycled off-cuts. The mandrel really help give a clean break with little filing to finish up,
Made heat treatment clamp to clamp rings. The DIY rings turned out to be equivalent bought out piston rings.
Making and heat treating rings now no longer a black art.

 

[BaronJ]

They were DIY from samples but modified. The Cap-Nuts were 10mm Brass Hex with M8 and the nipple M5 make. I still had some olive sleeves left.
See fotos-------DIY tube end fittings and engine breather tubing done. Too many bends will redo my way with one clean bend. May be running short of olives. No Problem.DIY olives. Tube bender is also DIY.

Not happy with too many bends. Redo breather tube to 2 bends that is a big bend and small bend. Now breather tube looks plain and simple and was easy to bend with plenty of lee-way to play with and then lock on.



Lotsa pressure .Thats good and this is because piston/rings and cylinder seating
well.

Hi Gus,

It looks a lot better in that last picture. It needed the elbow to make it look right.

Fine about your home brew bender ! It looks similar to one I made years ago when playing about with cars. I no longer have it ! It got wet and went rusty. It resides with the scrap man now, along with various other old tools that got a soaking in water.