richardm
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Post by richardm on Feb 14, 2024 16:52:35 GMT -5
I dont think they resistive. Resistors in spark plug are meant to reduce radio interference . Aviaviation igniters are shielded.
I have a couple of jet engine igniters one is brand new and I never got it to spark with my exciter but it puts scary sparks out of an ordinary car plug... sparks strong enough to get slight visible erosion on the electrode Go figure ..
Also by using a car spark plug you dont need the spark gap tube as the plugs gap does the job
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richardm
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Post by richardm on Feb 14, 2024 17:01:44 GMT -5
I have just adde some pictures of my ignition system on my " fuel pump" thread for you to see
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richardm
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Post by richardm on Feb 14, 2024 17:47:53 GMT -5
I would also add that the capacitors we are using are rated to about 2 kV with is way below what most aircraft turbine ignitors needs to jump their gap. May be some older igniters work at such a "low"voltage but mine dont. Aircraft mechanics are warned about working on ignition system can kill em if not properly handled.
You need about 3kv to jump a one millimeter gap in dry air. Personally I wouldn't try to push my luck to far by overcharging a microwave capacitor way above its rated voltage and make it explode I did explode some smaller electronic caps Not an enjoyable experience
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Post by wannabebuilderuk on Feb 16, 2024 17:34:27 GMT -5
andym for this rate I'm guessing you're using 3 or 4 modules? youtu.be/SnTSst5cHi8Was thinking of getting this as works out cheaper if some fail instead of the 2 for £8 you sent. amzn.eu/d/eQxgCv4Also I wonder if you wired two capacitors in parallel would the spark have more energy since higher capacitance, think I could fit 4 modules and 2 caps in my box 😁
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richardm
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Post by richardm on Feb 16, 2024 17:41:02 GMT -5
2 caps in parallel would give you more energy at the expense of a slower spark rate as it takes longer to charge em up
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richardm
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Post by richardm on Feb 16, 2024 17:56:52 GMT -5
2 caps in parallel would give you more energy at the expense of a slower spark rate as it takes longer to charge em up
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richardm
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Post by richardm on Feb 16, 2024 18:11:26 GMT -5
Only one cap on mine and good ignition I dont think your problem resides there What kind of plug are you using? Is your diode still good? I d rather try to work on the placement of the plug I did experiment by spraying fuel in open air and placing the plug at the end of stick to see if it ignited at all If it does then you have enough energy. It is then a matter of placement air and fuel flow
Again from literature despite calculations etc it still has a little black magic to it Once you get it right it becomes PFM Pure F....g Magic
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Post by andym on Feb 17, 2024 12:11:36 GMT -5
andym for this rate I'm guessing you're using 3 or 4 modules? youtu.be/SnTSst5cHi8Was thinking of getting this as works out cheaper if some fail instead of the 2 for £8 you sent. amzn.eu/d/eQxgCv4Also I wonder if you wired two capacitors in parallel would the spark have more energy since higher capacitance, think I could fit 4 modules and 2 caps in my box 😁 always good to have spares, which drop down transformer have you used...... 3 high valtage units.... but the spark gap also changes the rate of fire....
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Post by wannabebuilderuk on Feb 17, 2024 13:28:08 GMT -5
andym for this rate I'm guessing you're using 3 or 4 modules? youtu.be/SnTSst5cHi8Was thinking of getting this as works out cheaper if some fail instead of the 2 for £8 you sent. amzn.eu/d/eQxgCv4Also I wonder if you wired two capacitors in parallel would the spark have more energy since higher capacitance, think I could fit 4 modules and 2 caps in my box 😁 always good to have spares, which drop down transformer have you used...... 3 high valtage units.... but the spark gap also changes the rate of fire.... Going to see what the current draw is for 3 of them but guess probably 2a each so a 10a supply should do the trick even if it's closer to 3a although this could work and is cheaper www.ebay.co.uk/itm/266624168027
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Post by wannabebuilderuk on Feb 18, 2024 7:44:48 GMT -5
Was thinking about electric start and it's just occurred to me the shaft is right hand thread which is opposite of what it should be for direction? ![](https://i.ibb.co/bJgF9t9/20240218-124234.jpg) Might have the get a 2nd nut and loctite it on to make sure main nut won't come off and that would give me something to engage with bendix clutch without chewing up main nut. Think it's a 3/8-24 unf
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richardm
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Post by richardm on Feb 18, 2024 8:09:58 GMT -5
Mine was a l/h thread. Kind of weird yours is r/h... Anyways I just undid the nut and applied permanent retainer (permatex 64000) and retorque it. No way you'll unscrew it unless you heat it t0 around 400 F I have been told that Loctite green is a little better
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Post by racket on Feb 18, 2024 15:53:39 GMT -5
Hi Ben The starter will only tighten the nut , I used similar on my 12/118 engine postlmg.cc/jCTy37hR , theres no way the nut will loosen if its tightened correctly , I did some testing once to check and we've got a 100% margin Cheers John
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richardm
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Post by richardm on Feb 18, 2024 16:05:40 GMT -5
Right about the starter this case. I used retaining compound as mine is left hand That stuff challenges any attempt to undo a bolt or nut unless you get it hot enough But i find it weird that wannabebuilderuk has to deal with right hand nut.It kind of goes against common sense. You dont want that nut to come loose on any turbo. By the way those 12 points l/h nuts are not easy to find.
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Post by racket on Feb 18, 2024 16:34:00 GMT -5
Hi Richard
I use some Loctite between my LH threaded nut and the comp snout face to prevent slippage at high power settings even though theres 60 ft lbs of torque on the 1/2" LH UNF nut .
Some of the Holset/Cummins shafts have RH nuts , the Garrett TV94 shafts I've used have RH nuts , but the quill is stretched on tightening the nut 7/16" UNF nut
Cheers John
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Post by wannabebuilderuk on Feb 18, 2024 17:58:51 GMT -5
Hi Ben The starter will only tighten the nut , I used similar on my 12/118 engine postlmg.cc/jCTy37hR , theres no way the nut will loosen if its tightened correctly , I did some testing once to check and we've got a 100% margin Cheers John Hi John, I'm assuming the turbine and comp wheels are individually balanced so I would be fine undoing the nut and re torquing with thread locker if needed? I think it must be pretty solid as didn't move when I tried with the 14mm ring spanner (a hair too big but close enough) and holding the blade. If I put another nut on to act as the main one for a bendix to engage instead of chewing up the main nut I guess I wouldn't really need to worry about it being balanced since it's such a small mass close to the centre? Food for thought anyway, nowhere near ready to think about a starter anyway gotta finish wiring it all up and getting the spark to ignite, hopefully the plug is in the right place and it's just the diesel being a cunt lol.
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