For context, it's probably worth pointing out that in all the important 'road usable' power aspects, Monty's Duratec is already streets ahead of the Duratec in Caterham's range topping 420R. Ignoring the very top end for a minute, if you look at the power being made at 5,500rpm you'll see Monty is making a mighty 30 horsepower more than the Caterham at this point. Furthermore, if we look at the mid range punch, even more impressively Monty is also making 21 lb/ft more torque than Caterham's top of the line 420R!!!

The A.L. Developments ported head, +1mm valves, and Newman PH3 cams are all clearly doing their thing, as we're already producing substantially better cylinder filling in the midrange and up to 5,500rpm than Caterham's 420R. Indeed, up to 5,500rpm I'd actually change nothing about Monty, so all we're really chasing now is a climbing power line from 5,500rpm to 8,000rpm, which should culminate in an 18% higher peak horsepower number that is largely only usefull for bragging about in the pub.

This is because driving on the road typically takes place from idle to 5,500rpm, keeping the engine spinning between 3,500rpm - 5,500rpm while riding the torque is the real way to make rapid cross country progress on the fun roads. Running Monty's Duratec from 5,500rpm out to 8,000rpm is really only track driving territory.

However, it's not all bad news at the top end, far from it, as it's here's where we find we've also given Monty a whole new engine. Rather than completly falling over at 5,500pm, on the new head and Phase 3 cams Monty dogedly refuses to give up as he holds onto his peak horsepower number produced at 5,500rpm, and all the way out to a heady 8,000rpm! No it's not a rising line, but boy it feels strong, and theres absolutely no question having that 21 lbs/ft and 30hp advantage over a Caterham 420R spec Duratec up to 5,500rpm makes for a very rapid road driven Trad chassis Morgan indeed.

What Monty will feel like when I do eventually find the missing top end power, I can only imagine? However, to be completely honest I'm in no particular rush to unlock it, because Monty is already rapid enough, and if I'm completely honest with myself those last 2,000 rpms are really only reserved for track day use anyway.

Thanks for listening, and following Monty's evolution chaps, I hope you're all enjoying the journey as much as I am? thumbs

[Linked Image]

Dave.

Last edited by Montegue; 10/09/26 07:20 AM.