it wasn't high compression that sold me, its the combustion chamber design which allows higher (higher being the operative word) compression with crappy gas than a traditional in head combustion chamber. i spend alot of time in rural iowa where the only fuel offerings are diesel and 89 octane varnish thats been sitting in their tanks for six months, so something that can run a tight squish on lamp oil would be ideal compared to a shaved 531 which requires 92 and a bottle of octane boost just to idle correctly. if that is not YOUR ideal setup then thats fine, but it is my ideal setup and it is apparently exactly what it was designed for.
thanks for thinking im an idiot though.
I'm not shy and i'm not gonna lurk for a year until i know all you little buzzwords before asking a question either. i may not have a degree in fluid dynamics or mechanical engineering (and neither do YOU!) but i understand how an internal combustion engine works and the differences between the various cycles etc. Of course if i described the operation of something just a little different, like a miller cycle engine, some of you would probably start flinging crap around like you're in an apehouse. way to think outsideside the econobox guys. you naysayers all must be right, this is a dead end technology and thats exactly why they are using similar systems in new cars. i know for a fact that mitsubishi uses a similar piston and head design for its FTO mivec motor, but hey what do they know its not like they have engineers working on their designs or anything. I would expect this on a honda civic forum, but i assumed volvophiles were a little more mature.
to you who realize that volvo spent thousands if not millions of dollars in researching and implementing this design for a specific purpose thank you for your input in helping me discover exactly what that purpose was.
Lets start off with this- I DON'T have a degree in engineering or fluid dynamics but I have worked on a flowbench to work heads, have you ever even seen one in person? I spent YEARS building performance engine for a living. I primarily built engines to run on PUMP GAS in street cars with as much HP as I could squeeze out of it.
What is the reason for a high compression engine to run on **** gas? Why do it with rare parts? If you are going ot run **** gas why waste your money?
So Mitsu uses a similar design in their MIVEC engines? MIVEC is like VTEC, an acronym. THey apply that name to their variable valve timing design, not the engine as a whole. And their compression ratios aren't that high either. What makes you think they would run on **** gas like you want?
What does that make the Volvo design good? I'm sure they dropped the design because it was not good otherwise they would have continued to produce it for years. If Volvo spent alot of money on the design would that cause them to keep building a failure? Nope.
You are only looking at one aspect of the design, not any changes in the stroke or rod length or anything else that can change how the engine operates with substandard fuel.
Did I say anything about a shaved head? Idle isn't dictated by only the head.
If you really want an engine to run good on **** gas you don't have to control the burn in the piston, you can control it in the head. Building the engine with the pistons out of the bore rather than stting way down helps control the burn. Shaping the combustion chamber properly will do more for you as well. Then you have to consider cam profile and ignition timing to control the event timing.
If the Heron was so good it would still be around. Heavier pistons and an akward combustion chamber design aren't what I would go for.
Poi was slightly more elegant in his response that I, but right as well.
Lucky- mabye we should lok up his SN as see when the last activity was?