Search found 28 matches

by staska
Tue Feb 05, 2019 7:41 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Whispergen mk4
Replies: 22
Views: 8072

Re: Whispergen mk4

Ok, will give it a shot. Maybe today.. Different question for you Ian - Your opinion on cast iron as hot side heat exchanger in "stove tope" stirling engine... Have some lovely pieces of cast iron in 150mm diameter, want to make kind of pancake covers in stead of stainless steel. Much easier to mill...
by staska
Mon Feb 04, 2019 4:07 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Whispergen mk4
Replies: 22
Views: 8072

Re: Whispergen mk4

Vinegear will eat aluminium too :( tried, also oxalic acid. The biggest problem - cooler contains also an internal sleeve made from cast iron..

Did you found any info on used solid lubricant for yoke ? It looks like mo2s grease, but i am not sure is it mineral based or silicone oil for example..
by staska
Sun Feb 03, 2019 6:07 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Whispergen mk4
Replies: 22
Views: 8072

Re: Whispergen mk4

Hi ! , no, not yet, have been busy with different projects..stil have to decide how to clean aluminium from scale..
by staska
Thu May 31, 2018 6:30 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Whispergen mk4
Replies: 22
Views: 8072

Re: Whispergen mk4

Pellets yes if super quality. But no - when to much ash. I am using them for heating, quality is not constant. I will make more photo. As far as i can see and feel - it some kind of moly or graphite filled grease. Not 10w40 sure.
by staska
Wed May 30, 2018 9:00 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Whispergen mk4
Replies: 22
Views: 8072

Re: Whispergen mk4

thanks for reply. I know that sad history of whisper gen. And any other kinematic stirling. And looking into it as mechanist with some metalworking knowledge and having lathes - it should be simplified. Now in the middle of cleaning. And dissambling cold hx and liner. Solid fuel or not - ground char...
by staska
Sun May 20, 2018 9:56 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Whispergen mk4
Replies: 22
Views: 8072

Re: Whispergen mk4

Adittionally - if you will get in touch with one of authors, could you ask for some info on lubrication, assembly, gap in piston rings etc..
by staska
Sun May 20, 2018 5:01 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Whispergen mk4
Replies: 22
Views: 8072

Re: Whispergen mk4

Mk5 was quite popular in germany, you could get them on ebay.de for 150 ey for not working, 1000-1500 used, 3000++ for new. But they have cracking hot side heat exchangers. About mine - do not imagine too. On one motor lime scale popped up cold heat exchanger and water got inside. On other dont imag...
by staska
Wed May 16, 2018 5:56 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Whispergen mk4
Replies: 22
Views: 8072

Whispergen mk4

Just got two of these, dissasembling and cleaning them. Bought for scrap price as natural gas boiler. With some pressure. But not nominal.

Sad part - small rust on piston, very minor on cylinder and a lot of gum/limescale on water side of cold heat exchanger..
by staska
Wed Jul 22, 2015 5:53 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: dwell on displacer
Replies: 16
Views: 11342

Re: dwell on displacer

In theory it adds up to 20% of power for gamma, in practice it showed close to 12% increased power. Dwell was set to 50%
by staska
Wed Jul 08, 2015 7:19 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Heat exchanger design with FastTrack, FlexiScale and ReScale
Replies: 1
Views: 3164

Re: Heat exchanger design with FastTrack, FlexiScale and ReScale

1. I suggest to copy Philips MP1002CA if Your engine will be air-charged. For H or He it is ok to use bigger ratio of dead-space.
2. You can do it, if you keep ratio of slot width to length, but compensate with number of slots for same purpose. In commo it is in 125-60 ratio.
by staska
Thu Jul 17, 2014 4:26 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Big Stirling Engine
Replies: 47
Views: 36183

Re: Big Stirling Engine

And it producing 1 kw of mechanical power from single candle :)
by staska
Thu Jun 12, 2014 5:43 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling essex - beta or gamma ?
Replies: 6
Views: 5316

Re: Stirling essex - beta or gamma ?

Yes. http://www3.nd.edu/~me463d18/Files/Derek/Sources/gamma_testing.pdf With essex, it should be even better - we could negate any dead space with common swept volume. But - gamma gives posibility to make thin-tube heat exchanger for hot end without additional piston ring... "academics" http://paper...
by staska
Wed Jun 11, 2014 2:45 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling essex - beta or gamma ?
Replies: 6
Views: 5316

Re: Stirling essex - beta or gamma ?

Interesting info :http://arc.aiaa.org/doi/abs/10.2514/6.1994-3952 or http://papers.sae.org/929026/ Quote: It was demonstrated by analytical means, that the specific work obtainable from a Stirling type engine, with separate power and displacer cylinders, having the power cylinder connected to the ho...
by staska
Sun Jun 08, 2014 11:58 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Stirling essex - beta or gamma ?
Replies: 6
Views: 5316

Re: Stirling essex - beta or gamma ?

Does any-one have any ideas ? Does essex stirling engine is the answer to question about typical 1/1.5 ratio of power piston to displacer found in normal gamma engines with cold expansion space ?
by staska
Wed Jun 04, 2014 10:50 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: volume of tubing vs cylinder displacement
Replies: 6
Views: 3143

Re: volume of tubing vs cylinder displacement

I could disagree on dead volume non importance for engine performance. Going from pure gamma to beta with common swept wolume of only 22% of working volume have added 50% more power. But, that is more important - alpha engines with only two cylinder is the worst case of forced-to-indicated case of 0...