If you were in the UK I would suggest the Jaguar V12, at 5.3 litres it is certainly powerful enough, all alloy 60 deg V,OHC,. carbs or injection, points or electronic, and (over here) cheap.

Top right hand corner, is the spacer block that sits in the front stub spar behind the lower engine mount, center top row, oil seal carrier/bearing retainer for main wheel, bracket almost central in pic, looks like wing aux spar fixing.

Possibly another approach would be to have an entirely solid section as per your front web, (with lightening pockets) but instead of 0.75″ more like 2″ out as far as rib 6 or 7, to allow the U/C and radiators etc to stay in situ, then straight booms and web plate beyond (either as the original, or else a simplified version); if you want the wings to remove they can do this at the join, and any concerns r.e the bending of the tubes would be negated.

The only thing I would add at this stage is, keep an eye on weight, as heavy machined plates are strong , but by the same virtue heavy, and although you are not flying with brownings an ammo, you don’t have a Merlin up front either; perhaps its worth looking into adapting the original design by starting with smaller tubes, but for every wing design you need to know the AUW and the stress limitations of the A/C.

The tube spar is also hollow through the center, outboard (thanks Mark) from around the pintle mounting points, the tubes then fall away progressively until all that is left is the outer one; from a manufacturing point, much easier to achieve than machining from solid, less waste, (obviously) from a structural point of view, the multi tube spar would fail progressively, whereas the machined one would go in one; not designed for large production runs, just a very clever way to achieve maximum strength, for minimum weight, indeed the Spitfires asthetics aside, probably the single best illustration of Mitchell’s application of genius. (almost a quote from Joe Smith)

Well I for one welcome the day that this modern technology takes over, at least there will be a few merlins left for the rest of us, but if you think that all Reno is about is speed then you are wrong, it is a combination of sight and sound, and the struggle to get the very best from old technology.

How will new engines and airframes over come the known problems of prop tip speed, and compressability, dirty air, etc, etc; if you just want to go faster there is already an alternative that makes F1 type engines just as redundant as all other IC types, it has the blades on the inside, runs at over 15000 rpm, and theoretically only one moving part, and was designed by a man called Frank.

Now days tractor pullers claim to be getting over 4000hp from a griffon, however that is for only a short time period, i.e the time it takes to drag the sledge 100m, but clearly an improvement has been made.

I am not familiar with the duration of a race at Reno (obviously longer than that) but it seems likely that a race prepped Griffon would be producing approaching double the hp they were intended for, add to that, contra prop Griffons are freely available, (58’s) they would be my choice.