Search results

Help Support HMEM:

  1. Parksy

    Radial engines

    Hi all I was wondering how people go about machining the cam ring in four stroke radial engines. A conventional cam is relatively straight forwards to machine using a mill and rotary table. Can a cam ring be done in a similar fashion? Things I've learnt so far are that a 9cylinder radial has...
  2. Parksy

    Parksy's V4

    Hi all It's fair to say that I've finished my v4 engine. I did get it running using spark plugs, but the glow plugs are so much easier... https://www.youtube.com/watch?v=7s75C8vj90s&feature=share Here is a link to my build thread...
  3. Parksy

    Electronic headaches

    Hi all If I have 2 dual output coils running four spark plugs, both coils being run by a driver each but all share the same common ground and power supply, is it possible that while one coil fires, a stray voltage could be sent to the non firing coil? One of my coils has stopped working and...
  4. Parksy

    Piston to head clearance

    Hi all I've almost completed my v4 engine and attempted a start. While it does fire, it isn't self sustaining and I've attributed this to a low compression ratio. I'm not familiar with what my compression ratio is as I don't know what capacity I've machined the chamber in the heads, but I...
  5. Parksy

    Spark plug boots

    Hi all I've got an idea for making some spark plug boots, starting with a brass cap and the lead soldiered to the cap. Then heatshrink over the lead/cap and insulator. I was just wondering if there's anything I need to know regarding the leads. Specific grade of wire, insulation thickness...
  6. Parksy

    Wasted spark ignitions

    Hi all I was planning on running a wasted spark system on my v4, but I may have issues with this. The plan was to run a dual output coil on each bank with 2 sensors on a wheel located on each camshaft. So both spark plugs running off the one coil on each bank. But I've realised that there is...
  7. Parksy


    Hi all I have turned some tappets for the v4 engine using an unknown material that i had lying around the shed. My suspicions are that it was stainless, but it didn't appear to be a drawn rod, but ground. Does stainless come supplied as ground rod? Is stainless a poor material to use as...
  8. Parksy

    Confirmation on cam timings

    Hi all I have several questions that are important and I hope they make sense. When talking about cam duration, this is measured using crank degrees and not cam degrees? So if I want a duration of 220 degrees for example, I'd be leaving 110 degrees of material if I used the rotary table and...
  9. Parksy

    Valve seat cutting

    Hi all I have some 90 degree chamfer mills and was wondering how well these would work at cutting valve seats into lg2 bronze? Will they cut concentrically? Will they actually cut or would I need to grind a bigger relief behind the cutting edge? Thanks all Andy
  10. Parksy

    Securing a gear to a shaft

    Hi all I was wondering what methods everyone uses to positively secure a gear to a shaft? Previously I'd just use a grub screw against a machined flat. A woodruff key would be nice but I won't go this option. Are there any other methods that I don't know about? Thanks all for reading. Andy
  11. Parksy

    Firing orders

    Hi all This part of multi cylinder building always leaves me scratching my head. I'm building a v4 with a 90degree v block and crank throws 180 degrees apart. If I plan to have the engine run counter clockwise when viewing from the front the firing order will be 1 4 3 2. Now the part that...
  12. Parksy

    Hall effect ignition systems

    Hi all For my current v4 project id like to employ Hall effect ignition. As it has two camshafts, I'd like to have two sensors running off each camshaft to run two spark plugs. This would mean I'd have a wasted spark. The main reason for this is so I don't have to run a distributor. Does this...
  13. Parksy

    Making spur gears

    Hi all For my latest project I plan to use spur gears to run two camshafts on either side with the crankshaft run in the middle. I haven't given any thought with regards to the distance between the crankshaft and camshaft and the gears required to rotate them. What is the best way to...
  14. Parksy

    Piston ring failure

    Hi all Something that has intrigued me is when people say they haven't had any luck making cast iron piston rings. I have done the research and am aware of the different methods everyone employs when making them. My last engine employs piston rings and works nicely with good compression, at...
  15. Parksy

    Parksy's v4

    Hi all I've started another project, this one being a v4. There aren't any plans as I'm designing it on the fly as I did with my last engine. So far I've drilled and bored the crankshaft/camshaft tunnels and cylinder bores. The cylinder bores will be sleeved with cast iron liners. I've...
  16. Parksy

    V4 engine

    Hi all I'm after information on a V4 crankshaft configuration. Does it only have two throws(two rods per throw)? Are they 180 degrees apart? For an even firing pattern, what angle is the V in the block? I'm assuming 90 degrees, but I'd like to make sure first. Thanks all Andy
  17. Parksy

    Hand starting an engine

    Hi all I feel stupid asking this question, but what is the technique to hand start a four stroke engine by hand? I mean, what position is the crank at? I've tried bottom dead centre on the compression stroke and tried flicking the flywheel over and I can get a few pops. Any other position of...
  18. Parksy


    Hi all A couple of random questions regarding fuels. I've run one of my engines on pre mixed nitro fuel bought from a hobby shop which is a blend of nitro and oils and other things and I've noticed that the blow-by which is mostly oil by the looks tarnishes metal. What is causing this? I...
  19. Parksy

    Basic Hall effect question

    Hi all Quick question on Hall effect ignition systems. Which way does the magnet have to face the sensor? Does it matter? I've got some small disc shaped neodymium magnets which I intend to use, are the flat sides the N and south poles? Does the flat section need to face the sensor? Or will...
  20. Parksy

    Taper locks

    Gday all Can someone please explain or show me with some pictures the taper lock system used to secure flywheels to shafts. I have a vague idea on how they work, but I'm just curious what components need to be made and what locks into what. I hope this makes sense Thank you all Andy