Atom 4R with 400Bhp??

[speedmachine]

All though you sound pretty convinced, I still think the 3.5 has this stiffer chassis from the factory, as this 15% stiffer is exactly what I’m told was the benefit from the upgrade to the 3.5 chassis instead of the 3.

So I think you are only right when converting from a 3, not so much from a 3.5.

[AlanP]

The 3.5 was stiffer than the 3, but also the 3.5R was made stiffer than the 3.5.

Of this I am quite sure, but as the old Ariel pages about the old cars are gone we'd have to find a review or ask the factory to be certain. 'Our Man In Cyprus' is sure as am I.

But all pretty irrelevant now I guess, unless someone is wanting to upgrade their 3.5?? I think Steve told me recently they have someone looking at adding the Sadev to a 3.5R. That'd be quite a retrofit, I'd love to know what it would cost!! £30k?

A

[cvjoint]

If there is one, I sure hope it has stronger, i.e. aftermarket rods:
"However, people are breaking connecting rods, so shops like 4 Piston Cylinder Heads have a line of engines to build."
"They’re pretty big engines from the factory – we’re bending rods at 400 horsepower, which is unlike Hondas in the past"
https://www.enginebuildermag.com/2019/0 ... c1-engine/

The other challenge is cooling. It's going to run hot like other single exhaust port heads. I don't know the sort of side pods that are coming but they need to be hefty to handle the load. As I'm learning for trying different engines in my Atom, the 4 port heads can likely output 100hp more for the same thermal load a single exhaust port head can. This to me is even more important than the power differential. Owners have overheated the Civic Type R in stock trim at the track whereas no performance Honda in my recollection ever did that.

The good news is that the K20C1 is extensively used in motorsport by Honda and high end build houses like 4 piston racing are working on them. The future might be bright but I'm going to sit out and see what they can do first.