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Originally Posted by Soravia
I think it's for adjusting the cams, since most boxers sit far up on the engine bay, there's plenty of room to put stuff in the back of the engine than up front.
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The engine in the AS1's will be mounted ~9 inches further back than in previous Subarus. There will be very little room behind the engine.
Quote:
Originally Posted by Soravia
Will making vertical grooves on the piston skirt (without cutting too much into it to reduce strength) help enable higher RPM?
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No.
Quote:
Originally Posted by Soravia
How much of a harmonic is affecting higher engine RPM. (The pulley fore of the crank)
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Very little. The EJ engines do not have harmonic dampers and can run aftermarket lightweight main pulleys with no risk of shortened engine life. There is no reason to believe that the FB will be any different.
Quote:
Originally Posted by Soravia
Will changing crank and rod (increase rod length, reduce the crack turn radius) enable higher RPM?
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The stroke will not be the limiting factor of the stock engine. Stiffer valve springs, and possibly upgraded bearings and stronger connecting rods and bolts will be the first things to look into. And you'll need much more aggressive cams to make the extra revs worthwhile
Quote:
Originally Posted by Soravia
Not considering combustion process, what are other mechanical factors of the engine pieces that limit higher RPM? I see that F20C can rev to 9,000 RPM red line and it's just an inline 4. Boxers are supposed to be better at higher RPM operations.
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Valve weight, valve spring stiffness, steepness of cam profile, connecting rod strength, crankshaft strength, the weight of the piston/pin/rod assembly, peak piston acceleration (based on stroke and rod/stroke ratio), bearing quality, oil pressure/flow to those bearings and probably a few other things as well.
Quote:
Originally Posted by Soravia
I'm talking about having the FA20 run at 8,500 RPM making power all the way there without taking it to a race engine builder.
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That may be possible depending on the flow characteristics of the stock cylinder head ports/valves. Otherwise it will require head work at the very least. You're going to have to pull the motor no matter what, and if you need to change the rods or bearings you'll need to split the crankcase to do it. So whether or not you have to take the motor to a professional depends on how much you are willing to, or are capable of doing yourself.
Quote:
Originally Posted by Soravia
A separate question, I know cars have knock sensors next to cylinder walls. Is it feasible to have vibration sensors (accelerometers) on the engine in various angles to measure how much the engine is vibrating? It is used on aircraft parts to measure the conditions of engine and power-train parts, transmissions, gearboxes, drive-shafts, bearings, etc.
Thanks.
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Sure.