- Joined
- Mar 12, 2013
- Messages
- 313
At the recently held Isle of Man Classic TT races, several 4 valve Molnar Nortons participated, together with two 4 valve G50's.
Dyno tests reveal the 4 valve engines deliver appreciably more rear wheel horsepower than their 2 valve counter parts, yet through the Sulby speed trap they recorded slower top speeds. In all instances the aero part of the machines were identical, fairings etc, and with Michael Dunlop the rider of one of the 4 valve Nortons, rider ability to negotiate the Quarry bends prior to Sulby is without question.
There appears to be no reason for the speed discrepancy, certainly on accelleration the 4 valve engines excel, but to date all attempts to overcome this top speed dilemma have so far proved fruitless.
To add an even more curious detail, repeatedly the fastest timed single cylinder through the Sulby trap was a Royal Enfield Bullet.
All the above applicable to the Classic Senior TT class.
Perhaps from within the Forum membership there will be someone who can throw some light on the reason for the above speed discrepancy.
Dyno tests reveal the 4 valve engines deliver appreciably more rear wheel horsepower than their 2 valve counter parts, yet through the Sulby speed trap they recorded slower top speeds. In all instances the aero part of the machines were identical, fairings etc, and with Michael Dunlop the rider of one of the 4 valve Nortons, rider ability to negotiate the Quarry bends prior to Sulby is without question.
There appears to be no reason for the speed discrepancy, certainly on accelleration the 4 valve engines excel, but to date all attempts to overcome this top speed dilemma have so far proved fruitless.
To add an even more curious detail, repeatedly the fastest timed single cylinder through the Sulby trap was a Royal Enfield Bullet.
All the above applicable to the Classic Senior TT class.
Perhaps from within the Forum membership there will be someone who can throw some light on the reason for the above speed discrepancy.