Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Monty Takes A Deep Breath

Sump off, let's do this right and make sure Monty is overbuilt, rather than living on the bleeding edge of bottom end failure!



Standard 25,000-mile Ford silicon aluminium bearings out.



Slight scuffing, but nothing of particular concern given my enthusiastic use of Monty.



The Mahle Motorsport Tri-metal big end bearings have now been slipped in.



And all buttoned up with a set of ARP (ARPBE07) rod bolts that are specifically designed for use with the standard Ford rods that I'm reliably informed are a lot stronger than the internet will have you believe.



The rigid well supported and girdled bottom end of a Duratec is actually very robust if you use softer high-quality tri-metal bearings and secure the big ends with superior fasteners.

With the Mahle Motorsport Tri-metal big end bearings and ARP rod bolts in place, I'm confident we're building a bottom end that will deal with well over 250hp, with Monty's new horsepower output likely to land in the low 200's and with roughly 170 lb/ft of torque, we're actually building in a good margin of bottom end safety headspace.

Let's not spoil the ship for a hapeth of tar, and let's remain On-Brief!

Reliability, Drivability, Idle Quality, Safe Repeatable Performance... AND IN THAT ORDER

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

I've heard you can get 550 bhp out of the stock rods ... but only once! 🙂

Enjoying the thread ... thanks for posting (from someone trying to race a Midget with the unloved Triumph engine and walking a tightrope of how har the chocolate crankshaft can be pushed! 🙂)

K

Very good Image

As we know, Monty's setup uses the Fusion Fabrication long runner inlet which is actually a copy of the Mountune inlet that was part of their Ford approved MR200 tuning package, this kit gave an ST150 a genuine 200hp. Both the original Mountune MR200 inlet, and my Fusion Fabrications copy are designed to give good mid-range torque, but they're not really intended to function over 200hp!

I'm giving Monty a very special cylinder head with a significant lift in air flow, but also further improvements in port shape over the already very well designed Duratec head, and with 1mm bigger valves opened further and held open longer by a set of Phase 3 cams, finally the standard 38mm exhaust ports have been opened up to 40mm to help those exhaust gasses escape.

In theory all this means we're giving Monty a big uplift in air flow across the head, but let's not lose sight of the fact that even a completely bog standard Duratec head is known have sufficient air flow to support 250hp. My point is it won't matter how good the head is if the primary restriction to airflow is my long runner Fusion Fabrications inlet, which I suspect it will be! If the air can't pass easily through the bendy inlet *BEFORE* it reaches my fancy pants high flow ported port big valve cylinder head, then no matter how good the head is, I will never come close to releasing it's true maximum airflow potential!

However, if more outright power was my goal I would have junked the Fusion Fabrications inlet a long time ago. What will be super interesting to see is what effect the better breathing cylinder head and phase 3 cams will have on the 3,500rpm to 5,500rpm zone? If my calculations are correct, despite the 41.6mm id exhaust primaries remaining, despite me sticking with the potentially restrictive Fusion Fabrications long runner inlet, Monty's little Duratec should in theory deliver a fat slice more torque from 3,500rpm to 5,500rpm which is really what I'm after here.

And despite widening the lobe separation angle (LSA) by advancing the inlet cam and retarding the exhaust cam by 1 degree each from the cam makers base line numbers, the engine should also now continue making power all the way out to 7,500rpm instead of falling over at 6,500rpm as it currently does on the Newman Phase 2 cams. Of course the caveat here is this really is just theory at this stage, despite all the modelling and predictions we just don't know how well or badly the 'curly wurly' FF inlet will play with the new head and cams?

Monty should be complete and back in my hands this Saturday, but it'll be a while before I'm comfortable enough with my ECU calibration to take Monty to the dyno to lay down some numbers, so I'm afraid you will all need to be a bit more patient. However, I'm confident my bum dyno is going to reveal the general level of success very early on, so I'll try to convey my experiences as soon as I've fully exercised the new Stage 3 Monty.

Nice and clean up top, with no signs of detonaton to Monty's cylinder edges, or piston crowns



That's the excellent control from the EMU Back ECU, good atomisation from the 453cc Bosch Green Giant injectors, and of course Monty only exists on a strict diet of Shell V-Power too.

As we turn our attention to study Monty's cylinder head, we can see it's all helping to keep those comustion chambers super clean. The original head is equally clean, and thankfully also free from any signs of detonation.



I run it at:

* 14.7:1 @ Idle
* 15.5:1 @ Light load
* 13.5:1 @ Part load
* 13.0:1 @ Full load WOT

Clearly I'm not spending enough time at full load wide open throttle

Oh here we are, and here we are, and here we go

https://youtube.com/shorts/hN5Ht2FJuRA?si=JjmapcBcbbxVLygB

Tighter than a nun's chuff, this won't do at all A.L Developments

Those new high-spec austenitic stainless steel +1mm valves from Race Engine Components are indeed the dogs danglies, but they also have a longer stem!

Back to the machine shop we go, fortunately it's an easy fix and it'll all be sorted in no time at all

How is all this affecting your insurance rates ?

Returning to the cold air intake idea, here's Monty's current, and far from ideal, 'Hot Air' setup that needs sorting!





And here's a rough AI render showing our forward facing inlet idea, that not only allows us to remove the sharp turn at the the throrttle body and the further bends to the air filter, but also helps us create a 'Straight Shot' cold air intake.



I will also take the opportunity to replace the current Mondeo throttle body as used on the Duratec Plus 4, despite equiping Monty with a vastly superior metal version as first discovered by Rog, the standard 65mm size is really bigger than it needs to be, especially once youv'e removed the restrictive swirl flaps. Fitting the following Jenvey SFG60/0 throttle body will still easily support 300hp, but going down to 60mm will give better throttle control just off idle, and during slow speed driving.



The more apropriately sized 60mm Jenvey SFG60/0 not only improves low speed drivability by virtue of the smaller butterfly, it also delivers a progressive linkage by vitue of its eccentric throttle wheel that further improves drivability by changing the pedal movement to the butterfly opening ratio at smaller butterfly openings, this effectively softens throttle response as you pull away from junctions and trickle through town.

The smaller 60mm progressive linkage Jenvey SFG60/0 throttle body combined with the blended Alpha-N and Speed Density engine load stratergy, some additional ignition timing based tricks, and by advancing the Newman Phase 3 inlet camshaft by 1 degree, we should be able to deliver equal and possibly even better drivabily than a completely standard untuned Duratec Plus 4.

It's estimated by removing all the bends in the inlet pipe we could pick up as much as 4hp, estimates also suggest by feeding Monty's Duratec substantually cooler air we could add an additional 6hp. Combine the two and there's stong mathamatical evidence to suggest we'll enjoy a useful 10hp increase. All that with the better drivability offered by the 60mm progressive linkage Jenvey SFG60/0 throttle body, and we should end up with the perfect induction setup to pair with the torque producing Fusion Fabrications long runner inlet.

Looking at your intake temp reduction goal - I think you have an excellent opportunity here. That cone filter behind the exhaust headers is a bit of a disaster setup.

It’s worth getting some blister packs or use a laser pyrometer to do a current measurement of your intake temp to have a comparison before and after.

Quoting from Horsepower Academy discussion

“The air density will be about 0.003% greater for each 1degC reduction. I think the power change would be about .15% per degC, so a drop of 10 degC, could yield a 1.5% horsepower increase.”

https://www.hpacademy.com/forum/general-engine-building-discussion/show/intake-air-temperature-6/