Are you planning any mods with the con rods and pistons? Thinking surface polishing rods, matching for weight, drilling holes in piston skirts and suchlike.
No.
The exercise here is to make the most outright power and torque, but do so while retaining a good idle, adding meat to the mid-range torque over the widest possible spread in the rev range, and also retaining Monty's excellent throttle transients for optimum drivability. But to achieve all that safely,
without replacing the factory rods and pistons, which would effectively become an engine out rebuild.
You can always spend more money to make more power and add strength, but opening up the engine beyond the sump removal to fit the softer big end shells is unquestionably where we would start to see the spend increase considerably.
The next step up in strength would indeed involve forged rods and pistons, and building a Duratec to take over 300hp is actually a well trodden path. However, because it's an engine out job it's never gong to be cheap, and the truth is it's completely unnecessary here. This is because even if I did follow the herd and fit individual throttle bodies to Monty, we'd still be unlikely to exceed 245hp and 190 lb/ft.
For the low 200hp and 170lb/ft numbers were shooting for here (using the long runner Fusion Fabrications inlet), the Mahle Motorsport tri-metal big end bearings are probably unnecessary too, however, we want to build in some engine safety head space largely to remove any fear of exercising Monty to his true new potential, but also prepare his Duratec to be ITB ready should I ever choose to go down that path?
If the objective ever becomes to exceed 245hp and 190 lb/ft, the approach would be to start from scratch by building a fully forged de-stroked 2.5 Duratec. This creates a super strong and free revving 2.4 that with my ported big valve head should in theory help to deliver 270hp plus and well over 200 lbs/ft of torque. However, my opinion is a 2.0 Duratec will always be the best balanced rev happy sweet spot. Finally, it's also my personal opinion that 220hp with 180 lbs/ft is the optimal ceiling output for a traditional chassis Morgan, as such this remains my ultimate target.
To quote our cousins over the pond, what I'm aiming for here is really best described as the
'Best Bang For Buck'. Actually, being honest with myself, if the objective really was to deliver the best value for money, logic and my wallet would have stopped me at Stage 2.
A well-executed version of my Stage 2 recipe, but with a prober cold air intake with fewer bends in it, has the very real potential to give any Duratec Plus 4 185hp and 165 ft/lbs, and in a small narrow tack low door vintage looking 930kg classic car on a beam axle, for sure that's more than enough to have fun with on the road!
The way I've always viewed a Duratec Plus 4, is it's a way more reliable high-performance Triumph TR3 with 'night & day' better ergonomics. Four years ago, I came very close to buying an almost perfect zero-mile restored TR3, but on reflection knowing how Ilike to drive, and how I can never leave anything alone, I concluded a Duratec Plus 4 was the no-brainer choice!
A Duratec Plus 4 is essentially a vastly super execution of that wonderful TR3 recipe, a recipe that still delivers huge driving enjoyment to this day!
Happy Morganeering everyone
