Purchased a Changfa R165 watercooled diesel engine, question about flywheel play

[Jesse McB]

After some running of the diesel i check on the valves and torqued the head nuts abit more. I noticed the exhaust valve  had alot of clearance, way to much like 1/8" The problem is the valve tapet adjusting screws metal is to soft, the push rod  made a indent in it.  And the thing is This is not the orignal tappet screw that came with the engine, i damaged the original when assembling the engine bot long ago, and i have a few spares of these tappet screws but turns out they are hot hardened steel!!?  the intake valve still has its orignal tappet screw and its it perfect shape, and made outta hardend steel. I can tell by using a filer that original tappet screw is very hard steel it dont want to file, but the replacements i have are soft and file away easily. Any way to harden them? Im abit dissapointed lol! Heres a pic of the replacement tappet screw with its push rod indent. And then a pic of the orginal tappet , both have same hours of useage about 3 hours.

[mobile_bob]

i am not familiar with the type of screw/adjuster you have pictured

did you make them up after losing or damaging one?

not knowing the carbon content of the thing, you could try the following

use an acetylene torch (oxy/acet) and heat the end that needs to be hardened up to bright red heat
and immediately drop it in a small can of oil, anything will work, try some auto trans fluid.

then check to see if it hardened by using the file test... if it did not harden
reheat again and drop into room temp water... remember the thing has to be fully red hot, almost orange in low light conditions.  then recheck to see if it hardened... if it did... great... go on to the next step

if it hardened, it will likely be too hard.... you will need to temper it back a bit, or it might shatter in use
to do this polish up the end so that it is bright and shiny and then put it on a cookie sheet and place into a preheated oven. set to ~375F or so.... be sure to preheat the oven first

let the thing heat up in there for maybe 15 minutes or so... then take it out and take a look at the polished end... you want to see a dark straw color, almost a brown color would be about right.   if it is a light yellow...

it will still be a bit too hard, simply increase the oven to 400F and let it come up to heat, and bake the little fellow another 15 minutes or so... recheck the color... increase a bit at a time till you get to about dark yellow/brown color...

if there was sufficient carbon in the bolt you used, you might be able to get this to work, actually if there is sufficient carbon content it "will" work.

if you can't get it hard from the first or second quench, it is likely there is insufficient carbon content to harden properly, you are then faced with one of the following options.

1. get a replacement adjuster from the oem, or
2. make a replacement out of high carbon steel, such as a piece of spring steel rod, you can anneal it and machine as you need and reharden it, or...
3. you can case harden the adjuster you have now, that you will need to probably take to a local gunsmith to have done, as he will have the necessary stuff to do it and will have enough experience to do it right.

good luck

bob g

[Jesse McB]

I will try the harding methods you suggested bob, and i will order in a few hardend fine thread m8 allen bolts that i could drill a spot out for the push rod to set in and cut a groove in the back for the screw driver bit. Yes i think I like the "making it myself" way to solve this problem.  

[Jesse McB]

I found just what i need! If you kook at the pic of what the orginal valve adjuster looks like, it looks just like an allen bolt but the head is bored out for the push rod. And the good news is the M8 allen bolt is  exact same size and dimensions as the tappet screw. The diagram of the allen bolt is same dimensions pretty much for then tappet screw except the tappet screw head is in a cone shape.

[mobile_bob]

it is also possible to bore out the socket end and then install a hardened insert or cup to fit the pushrod end.

is the pushrod end spherical? or ball end?

if so you could use a piece of carbon steel rod, drill an indention, heat it bright red and drive a ball bearing into the
indention to basically forge the socket for the pushrod.

then machine it down to size, cut it off and insert it into the socket end of the bolt, and braze it in.

reheat and harden, then temper to suit.

or you might be fine leaving it hard as hell, as it will be fully supported within the socket head bolt and brazed in place.

there are flat tappets that have hardened faces that are brazed in place on the end of the tappet head. i see no reason why this wouldn't work, that is if you have the ability and/or a small lathe?

having said that, it would be far cheaper to just contact one of those chinese guys and get a replacement adjuster, but where is the fun in that?


bob g

[Jesse McB]

Now thats another good idea! I will try that aswell i got ball bearings that should be of size and can locate some carbon steel, im gonna try a few methodes, only thing about getting parts from china is you can think its carbon steel but it may not!?
So im going to make the parts my self, be alot better id say!
I dont have a lathe but i wish i had one! it would be so much fun to have, ill be making many parts and stuff with it lol. im going to try to find a small one thats can work with metal, be nice to have around wit what tools i have lol! Most of my tools are for wood, not many are for metal work, i dont even have a welder! 

[Jesse McB]

I bought a bunch of electronic  guages and safty shutoff equipment for the little diesel! All on ebay! I already designed a electronic diagram for the comtrol box. Its made in a way if the engine overheats it will shutdown the fuel supply with a fuel shutoff solenoid i purchased aswell!  If the power cuts off for any reason the engine will shut down with the fuel solenoid. I bought 2 temp meters that will shut down the engine incase it overheats, if one frys or disconnects the other temp meter will keep going. Also i got an hour metre, rpm guage and volt amp gauge. Just right now im doing final painting touchups on the engine, and just waiting for over a dozen of them little china packages to come in after the holidays and i can complete this little money sucker!  

I cant wait till spring ill use it for a few things, im lookimg forward to making a little gokart with it! Ive used small 2.5 hp has engines but this will be like a 5hp gas engine buring off melted lard and baon fat!

[veggie]

Project is coming along nice Jesse !

A word of caution with your controls.
Make sure that your temp switches can handle the amperage of your Fuel Cut Out solenoid.
In your wiring diagram I did not see any relays.
Most automotive type temp switches can switch around 4 amps (or less).
Many fuel Solenoids use 20 amps to pull-in and 5 to 10 amps to hold-in.

cheers
Veggie

[Jesse McB]

Thanks for the feedback veggie! I do have a breaker switch just for the temp switches so I will include that into my control panel!

[Jesse McB]

I rotated the air intake port so its sticking straight up,  it adapts to the 32mm standard air filters that are easy to get.  I used 4 washers with 1" holes for full air flow. The intake is 1" as well so have to match them, it was a puzzle to do this but I figured it out after a little thinking. This was made with just a drill press. 4 large washers,  and 2 extra m6 hex bolts

[Jesse McB]

R165 Air Intake

[mobile_bob]

i wouldn't be afraid of the chinese when it comes to carbon steel, they understand it and its uses very very well.

as an example, i bought a set of rough forged chisels and gouges, and they came about as rough as anything straight out of
a back yard forge ever was... san's handles

iirc it was ~75 piece set and took me another 3 hours each to finish, make handles and fit them, and then to temper and sharpen and hone...

i would put them against anything from any first world supplier, beit swedish or japanese, from england or the good ole usa... they can take an edge every bit as sharp as a razor and hold that edge wonderfully.

you only get that if you have carbon steel, and you only get the necessary toughness by having the right amount of carbon in the mix.

the materials they seem to understand, but in order to keep costs very low, they like everyone else cut corners on fit and finish... apparently labor costs are getting higher over there.

as for you adjuster, i would be shocked if they sent you anything other than a serviceable part.

bob g

[Jesse McB]

I got a control panel made for the engine! Well its not finished yet but its on its way!!  Its gonna be on about 3 feet of bundled nerve lines so it can sit on the ground or wall and stay outta the vibration zone. 

I had to make my own tappet screw! The ones they sent were way to soft! So i modified the high carbon 8mm Allen bolt and its perfect! The hole bore for the rounded end pushrod is perfect it feels fluid like when moving the pushrod on it.

The control panel i made is simple, still needs the lights switches wiring and relay switch.  Its got 2 digital programable thermostats, for shutting down the engines fuel if it overheats, I got 2 just incase if one fails.  A digital RPM guage that uses the magnet and proximity   sensor, a DC voltage and 100 amp amperage guage, and a hour meter to top it all off! Nothing wrong with having a way to see the engines brain waves lol.

[Jesse McB]

Here is a pic of the sensor for the 2 digital thermostats. Made from a hollowed out fan switch, 2 thermostat sensors and some epoxy.

[Jesse McB]

Im working on making a remote oil filter, first thing is i need to rig up an oil pump since this engines oil transfer system is centrifugel splash and mist. So on this magical site in china that sells all things for these engines, and all other things sells these small universal trochoid oil pumps for a good price! Only $32 canadian, shipping included! They have an 8mm shaft, ebay i can get a small 12v dc motor for $20 and a coupling and ill have a oil pump for a good price!  ill get a remote filter adapter and oil filter cheap on ebay, and he. This engine will have a way to have cleaner oil and longer oil usage! 

 Oh and to mention ill equip it with an oil sensor to shut it down if it ever leaked out!