RichardSIA said:
Buick V6 is the daddy of the GM 3800 which should be familiar to everyone.
You might want to think so, but it's not anymore. Maybe if it were Y2k it would stand a chance. The engine is well over a decade out of production, and with just a few notable exceptions was used almost exclusively in cars that are entirely forgettable today. A Buick V6 is not a selling point to many people these days, if it ever was.
From observation it seems cars that retain the vintage look and feel sell for more than cars with drive-trains that will soon be obsolete and unsupported. No Pinto, Vega, Zetec, etc. Yes that does argue against the Suzuki's.
As I see it, the answer is a cautious 'yes and no'. Yes they want a vintage 'look and feel', but no they don't want actual vintage. There is nothing of the Buick V6 that gives either the look or feel of an old Lotus. An I4, be it OHV vs OHC, carb vs FI vs ITB, on the other hand certainly does.
Unlike you, I would argue that few buyers view 'flavor of the month' engines as a bad thing during that month. It's the flavor of the month for a reason...Because that's what people desire to buy at that point in time. So if you can knock the build out quick enough that the flavor of the month hasn't significantly changed, I'd argue that's actually the best way to go for resale. Of the engines noted, I do personally like the 215, but would definitely go with OHC/FI I4's (Suzuki/Mazda) for traditional-Locost resale, as that's what I feel most Locost (not Caterham) buyers are actually looking for. The Suzuki especially is down a bit on power though still too for what I feel most modern buyers would ideally want. The rotary could be fine too, with it's sporting pedigree, but sort of like the Buick V6 (although entirely different reasons) would mostly be so only for the 'right' buyer.
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So I'm struggling to understand the purpose of this. To exceed $10k sale price by any appreciable margin typically requires a well sorted and well done car, both mechanically and cosmetically. Even with a solid and bargain priced staring point, you're still not going to make very much money on this, especially not if you factor in even a fraction of the time, effort, and frustration involved. No matter what engine you put in it, you may very well end up sitting on it for months and/or selling it for considerably less than you'd like, unless the right buyer just happens to come along. Locosts are simply too personalized to be easy to sell at any given point in time.
If it isn't going to be a 'keeper' project, I just don't see this contributing significantly towards progressing other ones that are. And if it doesn't, then what's the point? Figure out what you want to build for you, and just build it. Don't waste your time on something you don't actually care for or about.