Suggest some lightweight 4 cyl. engines please ..

Rover K-series. All-alloy, 113kg with transmission, 160bhp VVC variants are available, Lotus VHPD (Very High Performance Derivatives) ones make about 190bhp, really mad-spec can make 230bhp-ish.

Head gasket problems have been largely sorted out - fit a multi-layer metal head gasket from a Land Rover Freelander, with the correct metal dowels and the problem is mostly overcome. Provided the head's not warped or porous. And the cylinder liner protrusion is correct.

Treat them with a bit of respect (let it warm up before you thrash it, let it cool down at the end, make sure your cooling system is in top condition) and you should be alright.

4A-GE 1.6 engine & box from an MR2 Mk1

Plenty out there, cheap to buy, uber reliable, easy to tune, rev like mad...real little screamers - and the best bit is they are already set-up for a mid-engine.

Some details about the engine here: en.wikipedia.org/wiki/3AC#4A-GE_.2816-valve.29

Another alternative might be the later 3S-GE 2.0 engine from the Mk2 MR2 which started out with 150bhp and rose to around 175bhp in standard form (there is a 197bhp version, but these are harder to find and a lot more expensive!)

Details of the 3s-GE engine here: en.wikipedia.org/wiki/3S-GE

Well worth looking into either of these powerplants. Super reliable and quite easy to find. Sound nice too when screaming their lungs out....

Another vote for the Ford lumps, especially the mondeo 2 litre lump, being put in a lot of 7 style kits these days due to high power, reliability and lightweight, don't look at the Ford name and think they are rubbish, they'll do 200bhp on stock internals and are lighter than an old xflow.

I'd also say k series, get a complete mgtf rear set-up with subframe, hubs, brakes, suspension etc then bolt the lot in as one unit (4 mounts). you can use the cable gearchange, exhaust system and even the ecu system is easy to wire up. the vvc is a great engine 200bhp + is easily achievable n/a, i'm running around 170-180bhp with just a ported head, 421 manifold and better airfilter all on the standard mgf ecu! it still has the highest bhp to kg ratio for car engines and the vvc has great torque from idle to 7.5k rpm +

The one that immediately sprang to mind was those Yamaha-built Ford Zetec SE engines.

Great responses, thanks a lot folks.


Rich - thanks for the useful info. on the K-series. I'll sock it to my VW friend who likes muttering about their head gaskets everytime I say "Lotus Elise" to him.

Shedspeed - I would never have thought of a GSA engine! Sounds interesting but I doubt I'd find one easily and I found this:

Citroën A-Type Tuning
* 100bhp is maximum useable power for normally aspirated 4 cylinder Citroën boxer engines
* higly tuned engines have a greatly reduced life expectation
* tuning is VERY expensive

... I'd like to have potential for a bit more reliable bhp

Mystery Machine - "4A-GE 1.6 engine & box from an MR2 Mk1"
I'd thought of an MR-2 set-up. Seems like an wise and obvious choice. D you know what puts me off a little? It's the fact that it is obvious / predictable. Apart from that it sounds like a goer. I'll not shut down any options at this early stage, though, especially not a sensible one like this.

Kee - I wouldn't have thought of Ford and didn't know anything about their modern engines ... which is exactly why I needed to start this thread. The 1.7 Puma and Fiesta engine is part of the family, yes?
Which is the best one to go for if I'm looking for an easy 150+bhp? One point seven?

popuptoaster - That'll be the Duratec, yes? Any idea if these weigh much more that the Sigma mentioned by Kee?

gazwad - Aside from the MR-2, the MGF running gear sounds like the other obvious choice. You're a good salesman ... "it still has the highest bhp to kg ratio for car engines". That's exactly the sort of statistic I like to hear! ;D

berendd - Tritec (new MINI) engine ... again something that I know nothing of. I'll read up.

Is there anything French, modern, normally aspirated, rather sweet and crucially lightweight that I should consider?

If there was a website which gave some data on engine weights and dimensions it would be handy.

Honda V-Tec (again everyone loves 'em) ... lightweight or ...?

Alfa boxer engines 1.7 from the Alfasud Sprint for instance, are these fairly light?

Something French or Italian would be my ideal choice but I'm not shutting down any options.

Don't thing I can do turbo because limited space will cause cooling issues ... what about a supercharger? I've never had one ... best avoided for the same reasons or ...?

honda vtecs arent light, block is iron.

i think the peugot Mi16 engine is alloy and can get pretty good power from them. the 205 boys have claimed most though for conversions.

Not that lightweight. Something like the K20 out of the Civic Type-R comes in at about 160kg, without gearbox. However, they are 200-odd bhp out of the box and have the potential to do much more if you could find space for a turbo or supercharger (cf. Z-cars Mini, Ariel Atom)
Have a look here for a bit of comparison on weights and powers. It's off Austin Rover Online, so there is a slight K-series bias



As for superchargers, have a look at CR500Dom's Kadett running a supercharged Zetec-SE. I'm not suggesting just nick his idea, but... Well, I might be suggesting that. Does seem like a pretty good idea...