Hello from South Bucks
 

Hi, my name is Oliver and I'm a professional electronics design engineer. That pays the bills, but at heart I'm something of a petrol head. For me, that doesn't mean loud exhausts and license losing power but efficiency.

I've got a Caterham 7 that I built 33 years ago, and it's pretty close to a truly minimal car. Over the years it's gone from 130 BHP and 25 MPG to 155 BHP and 33 MPG, with plans for more improvements.

Welcome. This South Bucks? en.wikipedia.org/wiki/South_Bucks

Which was more difficult, 130-155 HP or 25-33 MPG?

What engine does the Caterham have?

Yes, that south bucks.
The Caterham has a Ford crossflow 1700cc pushrod engine, so originally 1960s design. I didn't really set myself power or MPG goals, so I can't say either was more difficult. The main goal was a genuine 300 BHP per ton, so I'm pretty pleased with getting 310 BHP per ton. I'm at 91 BHP per liter, and to go more than that gets really expensive. For those of you on facebook you can see more at facebook.com/CaterhamX300. For those not on facebook I'll post stuff here.

Thank you for that.

I actually like some seemingly "obsolete" engine designs. Even some sidevalve engines catch my attention once in a while...


No need to make much effort with such a featherweight ride anyway...

When is something no onger obsolete?
 

I did consider doing a bike engine swap some years ago, which would then be all 16V DOHC territory.
For road work I rarely trouble 5000 RPM+ territory, so pushrods work fine. With throttle bodies and an ECU, the oldest part of the engine by design is the 2 valve 'chamber in piston' design, which to be fair isn't clean burning.
Modern forged pistons gave a huge improvement in performance and fuel economy.

Unless you could find a 2-stroke :D

I need some help.

A year-old thread may not be the best place to ask.

Specifics?