[Good Vibes]

29hp sounds low, but is it low when compared to the Brit bikes of the 50's that is the era of bike that the Chennai RE plant began producing from its beginnings up to 2013 when the CGT was born.  But is it that bad?

From the 1992 edition of ENCYCLOPEDIA OF MOTORCYCLES edited by Erwin Tragatsch and revised by Brian Woolley, I  list the Brake Horse Power for the following motorcycles produced in the Post WWII era (up to 1959):

1. AJS Model 18 498cc            21.1 hp
2. Aerial VH Red Hunter 497cc 24.6 hp
3. BSA B33 499cc                    23.0 hp
4. BSA A10 GF 646cc twin        35.5 hp
5. Matchless G9 498cc twin      30.0 hp
6. Norton Manx 30 499cc         33.0 hp
7. Royal Enfield Bullet 498cc    25.4 hp
8. Ryl Enfd Meteor 692cc twin  36.5 hp
9. Triumph T 100 twin 498cc    34.0 hp
10. Velocette MSS 499cc          39.0 hp
11. Vincent HRD Comet 499cc   28.4 hp

So, given the light weight and superb handling of the CGT (and while it ain't a Gold Star), we should to be pretty happy with the on tap horsepower we have in our gorgeous little 535cc single banger so faithfully styled on the Café Racer's of the 50's and that it so  well represents - don't we?
The 60's era saw significantly more horse power from the 500 singles, but only in pure race machines and then multi cylinder bikes took over.

 

 

[longstrokeclassic]

Very informative post.  Makes you realise just how dark the rose tint really is 

[ROVERMAN]

I have the original version of the Encyclopedia of Motorcycles and is is my go to for any bike related questions, great book.
Roverman.

[Richard230]

I have a 22-volume motorcycle encyclopedia, called The World of Motorcycles, which was published in 1977 by Orbis Publishing Ltd., London and edited by Ian Ward.  A very impressive and interesting source of motorcycle history.  But it is getting a little outdated by now. 

One comment about those horsepower listings: I assume those are claimed by the factories and not tested on a rear-wheel dyno.  To me that would make them a little suspect and perhaps not completely comparable between models.  But still that is fun information and the power ratings sound about right when comparing their on-road performances. While I never owned one of those bikes, I always love to hear about them - and more so when someone else does the research. 

BTW, if anyone has a particular interest in British motorcycles I have copies of road tests from the 1930's through the 1960's that were published by a couple of British magazines referred to as the Blue'on and the Green'on.     I am always willing to look up a road test or two and comment on them here. (As an example, they were able to push a 1960 Bullet 350 up to 88 mph on their test track.) Those two magazines were very compete in their testing, much more so than any U.S. motorcycle magazine until the arrival of Cycle World in 1962.

[REpozer]

It's my assumption ( never assume)that the early British singles were long stroke engines.
Long stroke engines are generally designed for "work" or producing torque.
Part of the thrill of riding a RE motorcycle is riding within the" torque curve".

[la_r3_cgt_rider]

Very  .  How much HP does the pcv add to all those bikes? 

[1 Thump]

It's my assumption ( never assume)that the early British singles were long stroke engines.
Long stroke engines are generally designed for "work" or producing torque.
Part of the thrill of riding a RE motorcycle is riding within the" torque curve".

Generally yes, but I know that at least one of the listed bikes had a square motor, probably more.

[Otto_Ing]

Very  .  How much HP does the pcv add to all those bikes? 

PC-V is the equivalent of a carb tuning. Without other changes to the engine, intake and exhaust system it won't do much to performance.

With PC-V, free flow silencer and our airbox kit the GT lands up somewhere around 26hp at the wheel, which is around 33-34hp at the crank.

My bikes dyno chart.

[Rattlebattle]

I feel it's only fair to point out that the bhp quoted were real British horses and were actually delivered. Without tuning the actual bhp produced by the CGT is nowhere near 27bhp, more like 17bhp according to my supplying dealer's dyno.

As has been said, English classic "cooking" singles of the 50s were long-stroke with heavy flywheels (heavier in fact than the Indian Enfield Bullet) and some of them (particularly sidecar tugs like the Aeriel VB, Norton Big4 etc) were still side-valve. These fifties bikes were used for everything as few could afford a car. Fuel consumption mattered and often owners tried to eke out fuel as best they could. Only in the sixties when people began to have more disposable income and started buying Minis did more sporting singles emerge, often shorter stroke unit construction. The exceptions were of course Goldies and Velocettes, the latter being considered a bit anachronistic by the end of the sixties, the proper Goldies having ceased production in 1963.

I used to own a DB32 350cc Goldie; having ridden a CGT I can tell you that even at 535cc it is nowhere near as fast or powerful as a DB32 ( top speed 105mph) let alone a DBD 34 500.

[ace.cafe]

I think that the list has some inaccuracies.  The Bullet hp is crank hp, unless it was a Big Head model or Fury.
The Manx hp listed is at least 5hp too low.
But it does reveal the basic idea that the OP intended.

One of the important factors is that the old bikes were not strangled by bureaucratic regulations like the new ones are.  The new ones need to be freed of the restrictive cats and mufflers and intakes, in order to be compared to the old ones in an "apples to apples" comparison.

In that kind of match-up, the CGT 535 shows 25-26 rear wheel hp, as evidenced by the dyno tests of MeVoCGT and Otto in their "before" dyno graphs, equipped with free flow intake and exhaust and Power Commander to properly tune the mixture to suit.
In the "after" dyno test with the Ace head, and equipped with the same intake/exhaust system, it showed 32.5 hp at the rear wheel on an otherwise stock engine.
I feel that these are more representative of a comparison of similarly equipped machines.
IMO.

[Richard230]

Motorcycle Consumer News tested the GT when it was first introduced into the U.S. market. It produced around 20 hp on their Dynojet dyno and that was with a very loud "sports" muffler installed.  However, it was not broken-in as I recall and would likely have run better and made more power if it wasn't so new. It was tested against the Yamaha SR400, which didn't do any better powerwise and handled worse.

[Otto_Ing]

I can confidently state that my bike will beat the crap out of a stock bike at any given time. I think also the 25hp figure on MeVoCGT's bike does not give enogh credit to the intake mods we did to the airbox. Not wanting to start a bean counter discussion about 0.5 or 1 hp and dyno accuracies, so leaving it there. 

Nevertheless the toll to BS in form of restrictions and questionable technology is pretty impressive.

[Arizoni]

It's worth pointing out that any horsepower readings from a Dynojet are rear wheel horsepower.

It takes a special rig to tap the crankshaft directly to find out what the engine horsepower, without the losses in the transmission and drive chains actually is.

These drive losses at the rear wheel can be over 8 horsepower so it should not be surprising when a 27 horsepower engine can only get 17-19 horsepower readings on a Dynojet or other dynomometer.

All of the manufactures that make motorcycles test the engine  to determine the horsepower it can make.  They do not list rear wheel horsepower in the data they release to the general public.  It would serve no purpose except to make their products look under-powered when compared with the other motorcycles on the market.

The engine on the bike ace is talking about in his post above, with the ace head installed,  is actually putting out over 40 engine horsepower at the crankshaft.

[Otto_Ing]

It's worth pointing out that any horsepower readings from a Dynojet are rear wheel horsepower.

It takes a special rig to tap the crankshaft directly to find out what the engine horsepower, without the losses in the transmission and drive chains actually is.

These drive losses at the rear wheel can be over 8 horsepower so it should not be surprising when a 27 horsepower engine can only get 17-19 horsepower readings on a Dynojet or other dynomometer.

All of the manufactures that make motorcycles test the engine  to determine the horsepower it can make.  They do not list rear wheel horsepower in the data they release to the general public.  It would serve no purpose except to make their products look under-powered when compared with the other motorcycles on the market.

The engine on the bike ace is talking about in his post above, with the ace head installed,  is actually putting out over 40 engine horsepower at the crankshaft.

It's possible to measure transmission losses up to the clutch on the DynoJet rig. Which is what some "reputable" motorcycle magazines do and I plan to do next time I take the bike to the dyno. In the case of the Enfield we are missing the primary chain, nevertheless close enough. My dyno guy who usually measures Ducatis says they typically lose 10hp in the transmission.

[mevocgt]

I can confidently state that my bike will beat the crap out of a stock bike at any given time. I think also the 25hp figure on MeVoCGT's bike does not give enogh credit to the intake mods we did to the airbox. Not wanting to start a bean counter discussion about 0.5 or 1 hp and dyno accuracies, so leaving it there. 

Nevertheless the toll to BS in form of restrictions and questionable technology is pretty impressive.

That was with a stock replacement K&N.  I put the Ace/Dettro on with the head.