rtfm
Well-Known Member
Hi,
Although I already have an engine I'm wondering if it is going to work in the Razorback.
It is a Suzuki K10A motor, taken from a low-milage car. I have yet to weigh it accurately, but I suspect it is close on 200lbs, ready to fly. It is a very nice all aluminum engine producing in standard trim 103hp. I don't suppose it would take much to boost that.
However, it has one significant downfall. The fuel rail rises well above the rest of the engine (about 4 inches) and to the side. It looks suspiciously as though it will just not fit under the cowling - and I don't want to start incorporating bubbles in the cowling to accommodate it.
So as I get my mind geared up to begin building the new strongback and the fuselage which will surround it, I'm wondering if I shouldn't think about another engine. My thoughts run to the diminutive JB-DET - 660cc 4-cylinder, DOHC, 16-valve EFI turbo engine (as found in the Daihatsu Copen sports car). It uses an 8.2:1 static compression ratio and an intercooled turbocharger to help generate 47kW (63hp) at 6000 rpm and 110Nm at 3200 rpm (in Japanese spec). Again, I think to boost this modestly to 75hp or so for takeoff would not be too difficult.
Another possibility is the B70 1.0-litre as fitted to the Japanese market Charade G100 GT-ti. The CB70 (a development of the earlier CB60) uses a DOHC, 12-valve head with multi-point injection and an air-to-air intercooled IHI turbocharger. These features give the it 77kW (103hp) at 6500 rpm. Peak torque is 130Nm at 3500 rpm.
My problem is, I can't find the weights of either of these engines anywhere. I suspect the 1 litre 3-cyl Daihatsu will be lighter than the 1-litre K10A Suzuki 4-pot, but I don't know for sure. But from what I can make out, the 3-pot Daihatsu doesn't have the protruding fuel rail like the Suzuki. (see photo below)
So, my question is - if I opt for the much smaller (and lighter?) 660cc Daihatsu engine, how much airspeed could I realistically expect from the aircraft? I know Raymer talks about this in his books, but I can't follow the reasoning. Bottom line is the fact that I'd like to fly as fast as possible (who doesn't?) - hopefully in the 120kts (140mph) cruise rainge. And I suspect that 65hp in the cruise might not be sufficient.
Another possibility is the lovely AeroTwin motor ( • 65 HP @ 4200 RPM • Weight: 100 lbs) designed by Bill White of New Zealand (and that has GOT to be a good thing...) specifically for light aircraft. But it's expensive... (See 2nd photo)
Regards,
Duncan
Although I already have an engine I'm wondering if it is going to work in the Razorback.
It is a Suzuki K10A motor, taken from a low-milage car. I have yet to weigh it accurately, but I suspect it is close on 200lbs, ready to fly. It is a very nice all aluminum engine producing in standard trim 103hp. I don't suppose it would take much to boost that.
However, it has one significant downfall. The fuel rail rises well above the rest of the engine (about 4 inches) and to the side. It looks suspiciously as though it will just not fit under the cowling - and I don't want to start incorporating bubbles in the cowling to accommodate it.
So as I get my mind geared up to begin building the new strongback and the fuselage which will surround it, I'm wondering if I shouldn't think about another engine. My thoughts run to the diminutive JB-DET - 660cc 4-cylinder, DOHC, 16-valve EFI turbo engine (as found in the Daihatsu Copen sports car). It uses an 8.2:1 static compression ratio and an intercooled turbocharger to help generate 47kW (63hp) at 6000 rpm and 110Nm at 3200 rpm (in Japanese spec). Again, I think to boost this modestly to 75hp or so for takeoff would not be too difficult.
Another possibility is the B70 1.0-litre as fitted to the Japanese market Charade G100 GT-ti. The CB70 (a development of the earlier CB60) uses a DOHC, 12-valve head with multi-point injection and an air-to-air intercooled IHI turbocharger. These features give the it 77kW (103hp) at 6500 rpm. Peak torque is 130Nm at 3500 rpm.
My problem is, I can't find the weights of either of these engines anywhere. I suspect the 1 litre 3-cyl Daihatsu will be lighter than the 1-litre K10A Suzuki 4-pot, but I don't know for sure. But from what I can make out, the 3-pot Daihatsu doesn't have the protruding fuel rail like the Suzuki. (see photo below)
So, my question is - if I opt for the much smaller (and lighter?) 660cc Daihatsu engine, how much airspeed could I realistically expect from the aircraft? I know Raymer talks about this in his books, but I can't follow the reasoning. Bottom line is the fact that I'd like to fly as fast as possible (who doesn't?) - hopefully in the 120kts (140mph) cruise rainge. And I suspect that 65hp in the cruise might not be sufficient.
Another possibility is the lovely AeroTwin motor ( • 65 HP @ 4200 RPM • Weight: 100 lbs) designed by Bill White of New Zealand (and that has GOT to be a good thing...) specifically for light aircraft. But it's expensive... (See 2nd photo)
Regards,
Duncan
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