Now before I start, I get that the Locost mentality is keeping it cheap & simple, which excludes bleeding edge engines. It also excludes this engine due to its price tag, even though it has desirable properties for a locost, being both short (not too tall) and short (not too long). I get that these tall OHC engines are a pain to try to fit under a Locost bonnet.
But what I don't understand is why this engine was developed on this format. It was not developed for a locost
The rest of my post is more 'in general' rather than locost specific...
What's better about DOHC engines? What they are good at is convincing people to give more of their money to the manufacturers, basically.
I guess the main advantage is a lower valvetrain reciprocating mass. This can let you run higher revs, run weaker valve springs, reduce valvetrain wear (increasing reliability), reduce power needed to operate the valvetrain. Those are just the advantages of OHC, not DOCH. When you get to DOHC you can then easily ramp up to 4 valves per cylinder (yes, I know it CAN be done with OHV or SOHC, but the packaging constraints are tricky). When you get to 4 valves per cylinder, you can have lighter valves & weaker springs, (reducing valvetrain reciprocating mass & stress even further), smaller ports leading to higher port velocities at lower RPM (increasing efficiency) angled valves and higher total port & valve opening area given the constraints of a given cylinder (giving higher potential flow).
In general the complexity in modern cars is getting out of hand. At this point they are basically becoming disposable items. Very expensive disposable items. If you get a Locost running, there is no reason you shouldn't be able to use it for decades. If it's EFI you would probably have to replace that stuff periodically or move to carbs though.
I get that cars are too complicated and I agree. I miss tinkering with my SU carbs and the dizzy on my old Minis (I'm hoping a Locost will be a nice substitute
), but this added complexity does come with its own set of advantages. When you look at the performance of a good modern euro/jap engine and compare it to these LS engines, it becomes quite staggeringly apparent.
People are saying that the LS is an amazing engine, but I just can't see it myself. The power per litre for these engines isn't what I would consider stellar. I don't really know the world of the LS engine so please correct me if I chose an incorrect LS engine for this comparison. Compare, say, a 6litre LS2 producing ~400bhp (66bhp/litre) with a BMW S65 producing ~414bhp (103bhp/litre). Note that the LS2 uses 50% more capacity to produce less power. How this is an amazing engine, I am not quite sure. Granted, it has a LOT of torque and all the power is low down, is this the defining property of an amazing engine? Now, anyone know how size/weight compares on two engines such as these? I'm genuinely curious now as power/weight/size seems to be the primary discussion here, rather than power per litre which appears to be my angle.
Sorry i've gone on quite a bit, I was wondering if maybe I shouldn't post this as it may come across a bit trollish, but really I just love discussing pros & cons of different car tech. I'm not trying to bash these engines, i'm just trying to understand the appeal/advantages, I really am curious
I understand lots of the reasons given - simplicity, cost, knowledge - but are these really enough good points to throw away all that power? If they are then cool, I get it
As an interesting side note, against what I have been saying, my old 998cc BMC A+ engine would put out about 105bhp - about the same bhp/litre as the above mentioned bimmer engine. My Mini was 8v OHV and wasn't even a crossflow head (3 exhaust & 2 inlet ports). OK, so it made no pretense of trying to be reliable and no usable power below about 5000rpm (redlined at 9, destroyed itself at 9500+
). If that engine can do it, it's got me thinking even more on this subject now. *Sigh* why is there always one more thing to get you thinking
Oh yeah, when I grew up, most of the new cars did have "16v" or "OHC" or "EFI" or somesuch label in the branding to indicate the new tech being used. People *did* love to show it off hehe
Was it the same over here?