Highest pressure reached inside a cylinder in an alternative engine 1

[gmxiii]

Hi guys and thanks in advance for your time:

I've been looking around internet to the alternative engine ( not only automotive) with the highest peak pressure inside the cylinder. Does someone of younhave some info about this? It doesn't need to be a diesel or gas engine, it could use a Stirling cycle which it is my suspicious.

Best regards

 

[tbuelna]

gmxiii-

I imagine there have been some lab experiments where extremely high combustion pressures were achieved using a reciprocating piston device for a single cycle. As for an actual operational recip engine I personally spent some time on the design and testing of this diesel engine back in 1993-94. It was designed for peak cycle pressures of close to 300atm, but in testing we never were able to operate much beyond about 200atm for any length of time. The bottom end of the engine worked well and the engine structure was sound, but there were serious scuffing problems with the compression rings and upper cylinder liner. It was also a large displacement (92 cu in) single cylinder test engine with relatively unrefined combustion characteristics, which made it very rough running and noisy. Frankly, it was rather nerve-racking to spend more than a few minutes in the dyno room while it was running at full load.

Attached is a table giving some specs and performance data for the MTR (Monocylinder Test Rig) engine comparing it to an MTU engine benchmark of that period (20 years ago). The 112hp figure quoted at 2000rpm is accurate, and in fact I recall that we produced close to 118hp at 2100rpm on a few occasions. However the numbers shown for the MTR at 3000rpm and beyond are pure fantasy.

Hope that helps.
Terry

 

[gmxiii]

tbuelna-

Thank you a lot for your answer and for sharing your experiences it've been very rewarding. As you've said i also imagine the results that have been got in labs may be amazing but what i am actually looking for it is the "commercial" alternative engine that have reached the highest pressure inside the cylinder. Lets see if someone had this curiosity before and have the answer. Also from here i encourage people that, like you, would like to share theur experiences with radical engines.

 

[dicer]

Where those combustion pressures or pre combustion? 4410 psi?

 

[dicer]

What CR?

 

[gmxiii]

For all people interested, i got the solution. We are talking about indicated pressure (inside the cylinder) dicer. At the momento the engines with highest pressure are the ones from the dragster competition, which are designed almost for a single use. Check if you are interested for further information and thanks to all.

 

[tbuelna]

Where those combustion pressures or pre combustion? 4410 psi?

The 200atm pressures I noted were in-cylinder peak cycle pressures, measured using a high-frequency in-cylinder dynamic pressure transducer. The intake manifold pressure was close to 120psia and the scavenge pressure delta was around 8-10psid.

The actual trapped CR was quite modest, less than 12:1. This made starting the engine extremely difficult. As gmxii notes, the cycle pressures and power outputs are indicated values.