Quote:
Originally Posted by cRiPpLe_rOoStEr
Didn't you have a spare engine which you could use as a testbed? Or enough parts to make some sort of single-cylinder derivative of the 4G63 exactly to use it as a testbed prior to applying some design changes to your project, or maybe discarding some failed designs at a lower cost compared to a regular 4-cyl?
|
Yes, I have four back up testing engines now. Two of them are ready to test. The other two are prepping for a new block fill I'm testing for another company.
I'm still trying to figure out how to make a single cylinder engine that wouldn't cost me my bank account. lol One of my concerns after giving it some thought on doing a single cylinder test bed is that the other three missing cylinders effect on pulling the single cylinder through its three "nonpower stroke" cycles.
So, my thoughts are to finish making my run engine test stand and use my engines that are already done and ready to go. It definitely will save on cost. Then there is the thought I could just use the Camaro as the test stand. After doing some simple math I could change out one test piston and rod by myself in about an hour and 45 minutes. I'm leaning this direction because it will give 100% real test results. I keep all the benefits of a true test, Heat generated from the other three cylinders, torsional stress, exhaust mass and pulse widths, and the big one the lack of the power generated from the other three cylinders.
The single cylinder test engine would have helped me in the early stages of piston spray guided testing, but I think I'm past that stage now. My latest test on the Talon "72 mpg" has shown me that there isn't much low hanging fruit left over gains in my design.
There are three major things that are needed with my engines design. First is the static and dynamic compression. Static and dynamic compression I will address later because it's going to open up a can of worms on here with some back lash from people. Exhaust Mass is the third. I need all four cylinders to get the mass needed to make this work. During light load extreme lean burn the exhaust mass drops drastically. I'm running at negative 0.2 psi to a positive 1.0 psi load. This helps with the exhaust mass needed to obtain the positive pressure that's also needed for zero throttle pumping loss and high air lean combustion.