Andy_RR
Well-Known Member
The crazy man in my head has escaped from the asylum and is running around with the idea of making and engine based on Honda GX-series engine parts. Now the premise is that these engines are so ubiquitous that future parts availability is probably as guaranteed as the IC engine, not to mention all the random rip-off Chinese parts around, if you have a death-wish.
Anyway, I was thinking something like...
...a mini Merlin V12
So, spinning at (say) 3500rpm, assuming a redrive of some sort, with a BMEP of around 10-11Bar and lengthening the stroke to make it undersquare (for better BSFC and to keep the crankshaft length down) we have:
GX160-based:
Bore: 68mm
Stroke: 70mm
Swept Volume: 3051cm³
Power: 120hp
BMEP: 10.06Bar
GX270-based:
Bore: 77mm
Stroke: 80mm
Swept Volume: 4470cm³
Power: 180hp
BMEP: 10.29Bar
So, this gives a relatively lightly thermally stressed engine that doesn't require a bunch of exhaust or inlet tuning, but could yield useful power for the nutter kit builder. A real R-V12, anyone...?
Now obviously these won't be weight competitive with your average 912 or O-320 and I'll have to sit down and figure out exactly what something like this might weigh. Keeping it liquid cooled with low coolant volume, aluminium bores, pushrod, single cam in the V, light-as-practical billet crank, all the cheap tricks in the book to keep it as light as possible.
So what's the opinion out there on such a project?
Nuts? Barking crazy? ...or simply time to call the men in white coats?
Anyway, I was thinking something like...
...a mini Merlin V12
So, spinning at (say) 3500rpm, assuming a redrive of some sort, with a BMEP of around 10-11Bar and lengthening the stroke to make it undersquare (for better BSFC and to keep the crankshaft length down) we have:
GX160-based:
Bore: 68mm
Stroke: 70mm
Swept Volume: 3051cm³
Power: 120hp
BMEP: 10.06Bar
GX270-based:
Bore: 77mm
Stroke: 80mm
Swept Volume: 4470cm³
Power: 180hp
BMEP: 10.29Bar
So, this gives a relatively lightly thermally stressed engine that doesn't require a bunch of exhaust or inlet tuning, but could yield useful power for the nutter kit builder. A real R-V12, anyone...?
Now obviously these won't be weight competitive with your average 912 or O-320 and I'll have to sit down and figure out exactly what something like this might weigh. Keeping it liquid cooled with low coolant volume, aluminium bores, pushrod, single cam in the V, light-as-practical billet crank, all the cheap tricks in the book to keep it as light as possible.
So what's the opinion out there on such a project?
Nuts? Barking crazy? ...or simply time to call the men in white coats?
