I'm wading into an RV7 quick build kit. At first I only considered the VANS Lycoming XIO-360-A1B6 (200 hp) and the XIO-360-M1B (180 hp). I wanted the 200 hp unit for more speed. But, in the end I picked the M1B because it's $8000 cheaper and weighs around 30 lbs less. For that, I suppose I can give up 7 mph.
After asking VANS about ways to get more power for the M1B, I learned that several after market shops offered power modified M1Bs with increased hp. Of the main players in this market (I stuck with those listed on the VANS engine I D form), the most economical appeared to be the Mattituck TMX IO-360-M1B at slightly less than VANS price for the experimental Lycoming M1B.
The three power mod options they recommend are the 9:1 high compression pistons, the Hall effect Plasma II electronic ignition, and the front facing cold air induction kit. They claim a 190 + hp result. The cost runs slightly less than half the cost of buying the standard experimental 200 hp engine. Sounds good, but is it really worth the slight performance increase (maybe 3-5 mph?)?
I actually think the electonic ignition is a good idea (replaces right mag) as it looks like it would cause better combustion and timing for smoothness. And I'm okay with the cold air induction kit as helpful for getting denser air to the fuel mixture for greater power (costs a lot, though, for probably fractional power increase). Any pro or con comments are welcome.
I'm concerned about the non-standard pistons though. Could any of you engine gurus give the pros and cons of making high compression piston mods to an otherwise standard engine? I'm concerned about how much it might shorten the life of the engine and cause unneccesary strain and heat to the engine. Is the compression ratio increase from 8.5:1 to 9:1 enough to create a problem? Also, if I ever have a piston problem, it seems like it would be much easier to get a standard piston rather than a high compression one. Mattituck says that their high compression piston is actually a standard piston for another engine (the IO-320, I think they told me) which is slightly taller than the standard one for the IO-360-M1B engine.
So, I'm looking for pros and cons from anyone who's savvy about these sorts of things.
Thanks,
havent
PS: I'm also checking into simple airframe mods like vortex fins, gear fairings, etc. to see if a few more mph of speed can be found there. Any suggestions that have worked for others?
After asking VANS about ways to get more power for the M1B, I learned that several after market shops offered power modified M1Bs with increased hp. Of the main players in this market (I stuck with those listed on the VANS engine I D form), the most economical appeared to be the Mattituck TMX IO-360-M1B at slightly less than VANS price for the experimental Lycoming M1B.
The three power mod options they recommend are the 9:1 high compression pistons, the Hall effect Plasma II electronic ignition, and the front facing cold air induction kit. They claim a 190 + hp result. The cost runs slightly less than half the cost of buying the standard experimental 200 hp engine. Sounds good, but is it really worth the slight performance increase (maybe 3-5 mph?)?
I actually think the electonic ignition is a good idea (replaces right mag) as it looks like it would cause better combustion and timing for smoothness. And I'm okay with the cold air induction kit as helpful for getting denser air to the fuel mixture for greater power (costs a lot, though, for probably fractional power increase). Any pro or con comments are welcome.
I'm concerned about the non-standard pistons though. Could any of you engine gurus give the pros and cons of making high compression piston mods to an otherwise standard engine? I'm concerned about how much it might shorten the life of the engine and cause unneccesary strain and heat to the engine. Is the compression ratio increase from 8.5:1 to 9:1 enough to create a problem? Also, if I ever have a piston problem, it seems like it would be much easier to get a standard piston rather than a high compression one. Mattituck says that their high compression piston is actually a standard piston for another engine (the IO-320, I think they told me) which is slightly taller than the standard one for the IO-360-M1B engine.
So, I'm looking for pros and cons from anyone who's savvy about these sorts of things.
Thanks,
havent
PS: I'm also checking into simple airframe mods like vortex fins, gear fairings, etc. to see if a few more mph of speed can be found there. Any suggestions that have worked for others?
