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Old 06-03-2020, 02:55 AM
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Lufthans Lufthans is offline
Join Date: Dec 2017
Location: Hilversum, The Netherlands
Posts: 180

Thanks guys. Lots of good info here!

So basically it is either keep the pistons, rods, rings and cylinders together and be satisfied with 150 hp (or whatever it turns out with after the rest of the mods), or go all-out, but then be worried about the fact that it is a narrow deck engine.

Steve: the stuff that I am proposing isn?t all that heavy:
Add two EFI fuel pumps at 1 lbs each
Subtract a low pressure fuel pump
Add a fuel return line
Subtract the fuel valve
Add to ECUs (at 1 lbs each)
Add fuel pressure regulators, fuel rails and some piping.
Remove carb
Add (much lighter) throttle body
Swap out one sump for another.

All in all, I?d say I will not gain more than maybe 5 lbs.

We?ve got *some* ethanol in our mogas. Up to 5%. However after doing all this, my fuel system is 100% automotive. Could cope with much more ethanol than that.

Reason I want to go the EFI and electronic ignition route is 1: better starting, 2: smoother running, 3: reduced fuel burn (at $7 per gallon not something to sneeze at), 4: auto lean. After flying behind smooooooooth Subarus all the time, there is no way that I am going back to the 1930?s in fuel and spark.

Ed: good point about the higher compression ratio in combination with the narrow deck crankcase. I don?t care about the extra top speed (a theoretical 4.5 mph, so indeed almost negligible). The 250 fpm extra climb rate that 10 extra hp provides DOES matter to me though. My flying consist mostly of either formation flying, or dogfighting cumulus clouds. Quick dashes up to the cloud base, have my 15 minutes of fun and land again. 250 fpm matters. However, a cracked crankcase also matters.

Food for thought.
Hans Teijgeler
Hilversum, The Netherlands

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