Hello,

I have two requests but since they're related I’ll put them both in the same thread. I am building a project car which is duratec powered. I have a 2.3 engine with a Cosworth bottom end and a C30-94 Rotrex charger. I'm targeting 400 bhp at the crank.

Request one: Does anyone have a spare "high port" duratec cylinder head which they'd consider selling? Could be just the bare casting or a fully build head, I would be happy with either.

Request two. I've built a 1D simulation model of the engine to help me to design the Plenum (volume), intake lengths, choose camshaft specification etc. The crucial information, which I still miss, is a realistic CAM profile. I have emailed both Piper and Kent to ask for a lift profile but neither were willing to supply the data (despite it being something which can easily be measured from the parts). So firstly, does anyone already have this data for one of the following profiles?:

Kent DTEC2370, 2350, 2560, 2580…
Piper DUR2170, DURBP300, DURBP285…


Or failing that, does anyone have a set of these Cams which I could measure? I have a CNC mill with a touch probe + dividing head. I'm near Peterborough (Lincolnshire). I am fairly sure if I could accurately measure one of these profiles I could then scale it to generate the other profiles.

Thanks in advance.

Have a look at Catcams, they have lift profiles in their camshaft data sheets.

http://www.catcams.com/engines/engine-selection.aspx?SelectedManufacturer=8

There are 145bhp and vvt duratec options.

Dave

What information are you missing given in the Piper / Kent catalogues to generate the profiles?

How are you validating your model and what have you created it in?

Thanks for your replies.

I think (I'm no expert) that the model really needs an accurate representation of the lift curves when the valves are opening / closing. Between these events isn't so crucial. This means knowing the complete cam profile, not just the max lift, lift and TDC and timing.

I have setup the model based on accurate measurement of the engine with the throttle bodies, exhaust etc. which it currently has. Then I scaled one of the predefined cam profiles (comes with the software) so that the timing, max lift and lift at TDC match what is given in the Piper catalogue. When I solve the model, I see that the volumetric efficiency is low. You can then plot for example, flow at the valve throats against engine position which shows pretty serious flow reversal where it shouldn't be... This makes me think that the cam profiles which I'm using aren't representative.

Of course, it isn't really possible to correlate the complete engine model, and in any case it would be reaching for the stars to expect to accurately represent a thermal model. However, it should be possible to get close to a flow model of the inlet side. I have investigated some of the most influential unknowns (e.g. exhaust temp & volume) using a design of experiments. Taking the best result from there still shows poor cylinder filling, flow reversal etc...

In summary, I've modelled the engine, the flow is nowhere near where it should be and I think the cam profiles are to blame..

That was my point; I couldn't see any information missing that stops you from plotting a good enough pair of curves including their overlap.

What overlap do you have for your inlet and exhaust valves in your model?

You need to know that the maths behind your model is working as it should for the elements you are looking at. Otherwise, you'll either keep generating obviously wrong results or worse, sensible looking results that turn out to be completely wrong when used on a real engine.

Puma racing technical forum on Facebook and Turbosports forum are well worth a look

The 230hp NA spec cams are good. It depends what your aim is. But mine made 300hp and 240ftlb (from 3000rpm) at 7 psi of boost. I never took it further as I didnt need to, but the engine was built to take 14 psi all day every day.

Low overlap, high lift cams work pretty well with supercharged. Which points to relatively steep ramp angles, that info you can guess from the duration at 0.5mm lift figures if they are quoted.

This is a decent article https://www.enginelabs.com/engine-tech/inside-forced-induction-camshaft-designs-howards-cams/

Are you going for all out performance or street driving?

Loads detail in the sticky thread here too.