Off course Land Rover were not building these engines for power. They wanted them to go on and on working for months on end in the remotest parts of the world where they would run on low grade fuels poured out of rusty fuel cans.
Put a high performance engine with high compression ratios, fiddly carburettors, etc in those conditions and they won't last a day.

As with all cars, a compromise has to be made somewhere. You could probably get 200bhp out of a 2286 engine with a turbo at 7000rpm if you really tried, right before it explodes into fragments....

Craig.

Quote from: NoBeardNoTopKnot on Feb 02, 2024, 08:40 AM

Quote from: w3526602 on Feb 02, 2024, 05:31 AM

Does anybody know the difference between the 4-pot Rover car engine (nominally 80BHP) and the similarly based Land Rover engine (72BHP?)

I don't however I can make a pretty informed guess. In such a cooking-grade state, there's vast headroom in these engines for more air to be put thru'. It's never hard to get much, much more out of them. In stock form they are so strangled it's easy to remove the bottlenecks.

By the 70s a 2L engine would be expected to put out 90-100bhp (at the flywheel) and give 25mpg. Thus our 2.25 80bhp (at the flywheel)  and 20mpg is pretty poor. My breathed-on 2.8 does 105bhp ish (at the wheels), my guess 115bhp ish at the flywheel?

In 2.25 form using the same tricks (big-valve head; SU; cam) we can expect 95ish just as easily. We expect over 200 in modern closed-loop set-ups. With not much more than ditching the stock inlet manifold and love for the Zenith, I suspect 80bhp would be a piece of cake.

Thats a highly modified engine you have.
105 at the wheels would equate to about 140 at the flywheel when allowing for losses.
But then you should know your power at the flywheel if it's been on a dyno.
 

There is a real improvement when the ports in the head are matched to the manifolds and they run much smoother when the bottom end is balanced

Peter

Quote from: Bradley66 on Feb 02, 2024, 09:30 AMThats a highly modified engine you have.
105 at the wheels would equate to about 140 at the flywheel when allowing for losses.
But then you should know your power at the flywheel if it's been on a dyno.
 

It's ACR's 2.8 on a 5MB.. They claim 117bhp at the flywheel. I hope to grab some more soon, that's what the TPS on a cable-op pedal is all about in my other post. 140bhp, I can dream, doubt it though!

As for port-matching and the like, these engines were put together back with wide production tolerances, it really isn't hard to make decent improvements for not much effort. In fact you make most improvements BEFORE you spend much cash. Things follow the law of diminishing returns later!

Hi,

Thanks for opinions on the OHV engines.

OISE (overhead inlet side exhaust as fitted to the S1 P3 engines) was always considered to be a good idea. probably a layout that gives room for big valves.

On the other hand, fitting a Ford Transit engine was once a "good idea", but I have read that fitting a Ford V6 gave the most "bang for your buck" (until water comes out the exhaust as fast as you pour it into the radiator, or the fibre teeth fall of the timing gear at high revs. I've experienced both ... my Reliant Scimitar GTE was geared for 30MPH per 1000RPM, and red-lined at 6500RPM. It could also return 30+ MPG pulling a 12ft caravan round Devon and Cornwall. It was great fun teasing the Boy Racers away from the traffic lights ... stay slightly behind, until they changed gear, then "floor the loud pedal" (which is probably illegal).

602

602

Over the years, with exception of Ford's V6 and LR's 2.6 sixer I've had all the usual suspects. Had a V8, 200Tdi (definitely not a fan) and always fancied the V6, it's small and grunty without the hacking around, and heat of a V8. I understand there's ways round the fibre-teeth issue too.

I wound-up with a 2.8 17H more because that's what I had, and got my first by accident. I've come to consider a 17H the best compromise and have collected several.

Swaps are not so much the done-thing. My 2.8?  It feels like well....  I see a 2.8 17H as a hopped-up 2.25 3MB. That's true, it kinda' is, if you squint.