hcci test

[breezy]

well ive had this kicking around for a while now and as im locked down seemed a good idea to have another look
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had been originally inspired by flettner with his engine.( stole his starter set up). looks as though the piston rings in the adjustable combustion chamber are not sealing well enough to hold the required compression to fire up even with different types of fuel..https://youtu.be/9WzcnZaeYxw. i decided to put an outlet above the cylinder head piston to test the seal.....the piston ring set up has failed miserably where to go next? maybe a seal set up like that in a brake caliper with rubber seals. still need to fabricate a test system to test the head whilst its off. although ive started to make a simple cylinder head with a glow plug fitted to see if i can get the thing to fire up with rc fuel just to spur me on..:brick:/

[TZ350]

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Very Interesting. I would love to see more as your project progresses.

[breezy]

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Very Interesting. I would love to see more as your project progresses.

hello tz, got a few more pictures to post and videos... tried to tag them onto my first post but the video links kept failing, but i will try again:brick:

[breezy]

https://youtu.be/_Q4r6hQ5NsY https://youtu.be/KpJxgvEYZ98 i did couple it up with a small motor to move the piston but once the piston rings were fitted the motor was no longer able to move the piston up and down in a controlled manner.345150 picture of erg valve to keep the hot gaseinside the barrel.345151 this was original drawing for building the head.

[breezy]

345269345270 made a simple head for the engine today.... static compression 15:1 with a rc glow plug... see if i could get that to fire up.....it caught a couple of times but just not enough.:no:.. i think pulley on the motor needs to be larger to spin the engine over faster...i was using rc fuel nitro methane through the carb...

[Flettner]

Breezy, should it have a carbutetor?

[breezy]

Breezy, should it have a carbutetor?

well, im not sure .. there was a lot of residue coming out the exhaust port.. as though it was very rich. i think that a single rc glow plug probably wasn't sufficient for the amount of fuel entering the cylinder. The cylinder has very poor ports, no real blow down to speak of. maybe a spray bottle would atomise the fuel delivery better . im a bit stuck at present as i need a larger pulley wheel to get it spinning up faster. Ive recently had a massive clear out of my garage and all my junk has been binned or given away. :facepalm:. But although it only chugged a few times im almost certain its almost there.:laugh:. the compression is certainly there that's for sure. my adjustable piston cylinder head is probably not sealing very well due to my poor machining technique..i think i may try using the piston the rings came with see if that will seal... waiting on a few feabay bits to arrive to make a pressure tester, save keep fitting it then taking it off .... more to come..

[Niels Abildgaard]

well, im not sure .. there was a lot of residue coming out the exhaust port.. as though it was very rich. i think that a single rc glow plug probably wasn't sufficient for the amount of fuel entering the cylinder. The cylinder has very poor ports, no real blow down to speak of. maybe a spray bottle would atomise the fuel delivery better . im a bit stuck at present as i need a larger pulley wheel to get it spinning up faster. Ive recently had a massive clear out of my garage and all my junk has been binned or given away. :facepalm:. But although it only chugged a few times im almost certain its almost there.:laugh:. the compression is certainly there that's for sure. my adjustable piston cylinder head is probably not sealing very well due to my poor machining technique..i think i may try using the piston the rings came with see if that will seal... waiting on a few feabay bits to arrive to make a pressure tester, save keep fitting it then taking it off .... more to come..

With 1:15 compression ratio and rich mixture You will get north of 200 bar max pressure if it HCCIes.

[speedpro]

Not for long

[breezy]

i was kind of hoping it would fire up and die... asap.. pretty sure this engines big end wouldn't last too long with the high compression ratio.. i have attached the paper i read some time ago now....345367

[lohring]

Model engines have been successfully built with this system for a long time. They use a fuel that is 1/3 ether, 1/3 kerosene, and 1/3 lube oil. See the below links for more information.

https://www.flyrc.com/make-your-own-diesel-conversion-head/
http://www.cafes.net/doctordiesel/

Unfortunately, Robert Davis, the founder of Davis Diesel (https://www.facebook.com/davisdiesel75/), has died.

Lohring Miller

[breezy]

thanks lohring for these links, helpful to see how to fuel this kind of set up.... i have looked at the fueling i had tried, sort of off the cuff ,without any in depth look at the implications... i can see now why the engine spinning system im using began to labour significantly due to the increase in combustion pressure. as speed pro said " not for long"..... :facepalm:

[trevor amos]

Crikey Nigel is there nothing you won`t tackle?
Great to see you keeping your hand in with all this obscure technical stuff, I wish you every success with HCCI you may well succeed where other failed, inspiring stuff your doing .

Cheers, Trevor

[breezy]

Trevor, good to hear from you, its been a while. im a bit bored at present so im playing with my last little engine... got it to fire up today with the help of easy start..then my lashed up direct motor to engine linkage failed:brick:..... ran for a split second...should have set my phone camera up before, so its not recorded. still im happy:banana:....i recently got rid of all my bike bits and usefull scrap metal so im struggling to keep the project moving.
keep safe mate..

[breezy]

Had another play with nitro/petrol mix with igniter head 15:1 comp...sort of fires /run no extensive run time though..my variable comp head is causing me issues with sealing at tdc.... just trying again to address this..little you tube vid to add..

[breezy]

I've tried to add you tube video... but I give up...its on there ...nitro/petrol mix with igniter

[breezy]

https://youtu.be/CJwwJlcehPwi


Sort of fires but my fuel delivery system is crap !! It also doesn't want to know at all without the igniter battery..

[trevor amos]

Hi Nigel,
Great to see that you are still doing crazy, innovative and inspiring stuff, hope you get there mate, can`t wait for a new `Midlands`, perhaps next year.

Regards, Trevor

[breezy]

Well this is my design for my adjustable combustion head which is a rehash of the one i made earlier. It wouldnt seal ... If anyone has any advise on what i intend to do please comment.so Maybe it wouldn't be another wasted effort..347496

[lohring]

We did some testing with a 26 cc racing engine on glow ignition. We couldn't get the plugs to hold up. The plugs that could stand the pressure wouldn't constantly fire and the others blew out the center element. We probably needed to play with head volumes. On spark ignition it ran well on 15% nitro model fuel, but burned the electrodes off the plug on 40% nitro. I wrote an article on model engine head design. See namba.com/content/library/propwash/2019/october/4/#zoom=z if that helps.

Model "diesels" depend on a close fit with the moveable head and the cylinder. They're adjusted by a central screw. I'm not sure how well that would work on a larger bore. Our luck with this style piston on a 36 cc engine wasn't good. The head is a less exacting application, though. It needs to be very close to a zero clearance fit in a very round bore.

Lohring Miller

[breezy]

We did some testing with a 26 cc racing engine on glow ignition. We couldn't get the plugs to hold up. The plugs that could stand the pressure wouldn't constantly fire and the others blew out the center element. We probably needed to play with head volumes. On spark ignition it ran well on 15% nitro model fuel, but burned the electrodes off the plug on 40% nitro. I wrote an article on model engine head design. See namba.com/content/library/propwash/2019/october/4/#zoom=z if that helps.

Model "diesels" depend on a close fit with the moveable head and the cylinder. They're adjusted by a central screw. I'm not sure how well that would work on a larger bore. Our luck with this style piston on a 36 cc engine wasn't good. The head is a less exacting application, though. It needs to be very close to a zero clearance fit in a very round bore.

Lohring Miller

thanks, ill take a look at the article.. i had hoped my original piston ring sealing method would be the way to go and maybe i should have another go at it but improve my machining... or even try and press in a pre plated sleeve with an opposing modified piston. at least that wouldn't need me to up my game on the machining front.

[breezy]

tried the threaded piston ..... but still no satisfactory seal,,

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so Ive made a sleeve from a weed whacker cylinder and pressed that in and machined the piston down and coupled it to a shaft... my starter motor has burnt out so testing this is on hold till i can replace it..

[breezy]

348646 piston threaded, managed to groove the internal shaft to incorporate wire for a glow plug, which was then sleeved with chrome plated brass tube,

[Lightbulb]

That glow plug has the idle bar fitted to it. You need to try one without it. Also there is flat coil glow plugs that work well in 4stroke engines. Ontop of that they come in different heat ranges too, and different alloy compositions.
Neil