Tear Down and Rebuild of My R400 Duratec Engine

[aerobod - near CYYC]

1 hour ago, KnifeySpoony said:

My sender is in the oil tank, which is after the cooler (coldest point). I have seen various numbers thrown around re: the delta between tank temp and sump temp - does anyone actually have any hard data on this as measured on their car? I know it will depend on the cooler and tank/plumbing setup, as well as ambient temp, speed etc, but I have wondered how much hotter it really is in the bearings, head, and sump while underway.

Assuming the majority of oil cooling with the standard oil cooler happens at the cooler itself (maybe 1/4 in the lines, sump and oil tank) when on the move, the cooling capability doesn’t change too much once the airspeed is above 80km/h and assuming ambient temps are in the 25C range. The cooling effect can be estimated:

- Standard Caterham 10 row Mocal plate cooler can dissipate about 5kW / 5kJ/s (Setrab quotes 15,000 to 20,000btu/hr for the equivalent cooler)

- Specific heat of engine oil at 100C is 2.22kJ/kg/K

- Oil density at 100C is approximately 0.8kg / litre

- likely oil pump flow is around 25 litres per minute before pressure relief valve operation. So 0.4 litres per second is a good approximate value.

Temp drop at the oil cooler is therefore 5 / (2.22 x 0.8 x 0.4) = 7C

Allowing for 3/4 of the temp drop at the cooler, the overall temp drop would be close to 10C compared with the temp at the sump.

The upgraded oil cooler I have fitted has about 10kW cooling capacity, so hopefully I will see an additional 7C drop over the standard one.

[aerobod - near CYYC]

Decided that a grille on the nosecone top hole would be in order.

Some black 3x6mm diamond aluminium mesh from Amazon was formed into the shape of the hole:

Then using some 3M 4200FC (meant to be equivalent to Sikaflex 292i), it was bonded in place and left to cure with some weights on it for 24hrs (best workout SWMBOs kettle and dumb bells have had in 5 years 😀😞

They only had white the white version of 4209FC at Canadian Tire:

 

Looks better now with the grille instead of just the hole:

Hopefully that is job done on the cooling upgrades, next track day on Sunday (if the weather cooperates) should give me the answer.
 

[rgrigsby]

Quote

Hopefully that is job done on the cooling upgrades, next track day on Sunday (if the weather cooperates) should give me the answer.

Wow, the quality of everything you are doing on this car is amazing. I just wish I had the skills (and patience!), it's great to see the evolution as you go along.

Hope the weather holds out, enjoy the rack day.

[aerobod - near CYYC]

The cooling modifications performed well on the track today. Although the ambient temp was only up to 17C, I used plenty of revs on the track that is really just a set of medium to tight radius turns with a number of short straights, so it has lots of full throttle mixed with maximum braking with little part throttle use you would find with longer radius turns. Overall a taxing track for the cooling system.

Coolant stayed in the 80 to 85C range and oil (after the oil cooler) in the 75 to 80C range with a minimum of 5 bar pressure at higher revs. Overall about 20C drop and 1.5 to 2 bar higher oil pressure than 2 weeks ago on this track.

The car is quite a dirty mess now, though, as open trailering it with the tonneau and aeroscreen on for 600km with 150km of heavy rain got dirty water everywhere, with about half a litre to bail out of the footwells and under the seats when I arrived at the track. My previously nice clean engine bay isn’t clean anymore. Also, the initially damp track seemed to have lots of little worms in the puddles, so they are plastered all over the rear wheel arches with some other dead ones in the car. I had to come in after one lap to wipe a couple off my helmet visor. For some reason after the long drought period we have had up to this month, the worms seem to be emerging everywhere with this recent wet spell.

Only one glitch now to deal with, the inlet air temp sensor “tube” I created to isolate the sensor from engine heat and place it next to the intake trumpets seems to distort with engine heat and has loosened off a few times now. I used PVC plumbing fittings, but looks like I need a more temperature stable material, so I have ordered some 50mm diameter acetal rod to machine a new “tube”.

[7 wonders of the world]

so this cooling system revision really did turn out to be a 'can or worms'...... 

Glad to hear you have some happier numbers now,

mine showed very similar temps to those I had without the cooler on the 3 spirited roads blats I've had recently the later with ambient temp circa 21 degrees, I was seeing peak temps of (85-102) I chose the then optional 92 degree C stat though they offer a 102 degree C now (which I may well order) as well as the stock 82 degree C.

HEL inline oilstat

Due to my 85mm deep radiator and its location to clear the freestyle inboard I have to mount my cooler behind the radiator so not the ideal location however mine is a crossflow radiator so I do have ideal alignment of the tubes on the two cores to increase airflow.

Fan is a pull version which needs additional cowling strips to fill the gap between the fan and radiator caused by the oil cooler, that said it has no problem maintaining standing temps even in this form.

The oil stat fits pretty well under No 1 TB and sits nicely against the chassis rail, 

 

[aerobod - near CYYC]

I did look at the HEL oil thermostat, Neil, I ordered the Setrab oil cooler direct from HEL UK, the HEL Canada dealer is just a few km from me here in Calgary, but said it would be quicker ordering direct due to him not having one in stock.

The problem is that I would need to add more 90 degree bends and have custom hoses made to replace the existing ones feeding the oil cooler plus the connections to the.thermostat. Also, the only place nearby with space is under the oil cooler itself between the existing oil line fittings. Around town with low air velocities the oil and water temps aren’t much different than before, from a blat perspective out in the countryside, a piece of plastic over the oil cooler will work for now.

[7 wonders of the world]

Arh of course, your using the Kidney tank, my tank is in a short footwell so the plumbing was easier, 3 of the 4 unions onto the oil stat are straight the last one is a 45 degree then 2 new long hoses to the cooler,

I shortened the original scavage return hose slightly and changed the end, push fit into Goodridge hose to easy enough, and used a pair of 135 degree ends onto the cooler,