Talk Morgan Forums Community The Malvern Arms Quoted bhp vs tested

Never having been particularly bothered about quoted new/stock horse power, I was intrigued today to find myself at a 'dyno' test; apparently it's necessary to calculate the power to weight ratio and thus determine the accurate handicap in club competition. (Last year my car was weighed, 960 kg in race trim, but the hp estimated as I hadn't had time to get to an approved test station- it wouldn't matter because I wasn't likely to be competitive in my first season, let alone win anything!)
I duly handed over the keys, and was asked what I was expecting/hoping for. Well, a 21 Yr old car, with close to 120k on the clock, home maintained with the only mod being a K&N style air filter, in daily use fed on standard unleaded and any old 10w40, I wouldn't have been surprised to have lost quite a few horses; The 4.0 fuel injected RV8 installed is quoted at 187 hp, so quite a surprise to have found a few adopted at 201 bhp. Judging by the small blip/cough midway through, I think it was a good clearing out exercise too. I have no desire to add any more, but nice to know I don't appear to have done any damage over the past 4 years.

Good result especially as most quoted bhp are calculated nowadays from engine spec with the dyno results regularly falling a little short. One exception in the Morgan world seems to be the Cyclone 3.7 V6 on the later Roadsters which regularly shows higher on a dyno than the quoted 280 bhp, including mine I'm pleased to say despite less than ideal intake temperature.

When I bought the Aston, I had a sports exhaust fitted. I then had a dyno and it showed the BHP being the same as the factory quoted.

I am pretty sure your car will be GEMS, in which case I think a 200 bhp figure is good ,. but not unusual.

The earlier versions , Hotwire , Flapper, and carburettors were notorious for giving lower numbers than quoted, anything around 165 for a 3.9 and less for a 3,5 was not unusual.

Richard - I seem to remember a previous post on here from Germany where several 3.7 Cyclones were tested (for TUV certification?) and ranged from 304bhp to 307bhp . IIRC the Cyclone was rated at 304bhp when used in the Mustang and I would guess that the Morgan exhaust manifolds were more efficient than those on the Mustang.

Yes the US figures varied but we're always higher than the 280 bhp MMC quote. I've often wondered where they got that figure from

Could be they mixed up torque with bhp of course since the 280 lbft is consistently quoted here and US.

Yes the GEMS setup. Either way, I'm pleased and astonished it's retained it's original oomph!

Phillip, 120,000 miles and still the original camshaft, that's impressive .

David Byrne

Depends how accurate the rollers are though!

Arwyn

Apparently calibrated 2 days before. https://maps.app.goo.gl/CQ2sJ8vr44wmsKDTA