Which raises the question
@Tashfeen - why didn't you provide that link sooner? I am amazed that I never saw that thread. It's also amazing that
@arad85 has a worse memory than me!
Anyway no I don't understand Russian although I know a few people who could translate. However no need as I found the French one to download, and there is an English version
here (if anyone can work out how to download the pdf it would be great). I only wish I had seen this SSP before. I had searched the web looking for something but I guess my search terms must have been inadequate.
The first thing that the SSP reveals is that the CREC engine has more changes than I had previously thought. As we know, these changes were all to improve efficiency and meet the EU6 emission regs. The interesting highlights are:
- Redesigned oil pan
- The crankshaft is 1.67Kg lighter!
- Increased compression ratio
- Redesigned oil rings
- Redesigned PCV
- Supercharger belt tension increased
- Chain drive redesigned, including added exhaust cam adjuster
- Redesigned cylinder head - reduced weight - improved wear resistance
- DUAL FUEL INJECTION SYSTEM
- Redesigned oil system including switchable pressure pump
- Redesigned supercharger
- Modified coolant system
I don't know if the redesign of the oil pan includes the sump but I suspect it did. This is because on the old engine it is sometime necessary to grind part of it to prevent it fouling the belt when a bigger crank pulley is fitted, and this is not required on the CREC (at least it wasn't on mine).
The increase in CR could cause problems for those who want the highest pulley ratio because this enters uncharted territory.
The redesigned oil rings are claimed to reduce oil consumption. And the redesigned PCV means that there is no reason to suspect that this would be the culprit for oil consumption as it has been on the previous engine (although it does not prove that it couldn't be).
The belt tension has increased from 219N to 290N. I admit I'm not sure of any consequences for this but perhaps it could be a contributing factor to the few cases we have seen of the supercharger clutch slipping?
The camshaft drive chains have fewer links, saving some weight. I hope that in the redesign the problem of loss of tension (hence rattle) which could occur in the previous engine has been solved, but only time will tell. Presumably now that the exhaust cams can be adjusted as well as the intake cams the torque curve is slightly more optimised (although if so it has not shown itself on any of MRCs dyno graphs).
The dual fuel injection system: The SSP does indeed confirm that the CREC has both direct (FSI) and manifold/port (MPI) injection. There are 6 FSI high pressure injectors with the pressure increased from 150 to 200 bar. The injector positions have been altered slightly to improve combustion efficiency. The 6 new low pressure MPI injectors are positioned just below the intake manifold flaps. It is clear that this combination of FSI and MPI injectors is for EU6, primarily to avoid the need for a particulate filter (petrol equivalent of a DPF). The bonus is that the MPI injectors should help to avoid carbon build-up on the intake valves.
We know about the supercharger clutch and the SENT sensors. This SSP also confirms that the intercoolers are larger and angled for higher efficiency. This shows that the assumptions about tuning and need for uprating cooling do not necessarily follow for the CREC engine, or in other words it should be capable of handling a higher tune before needing an uprated rad. The chart about clutch operation proves what I suspected - that the logic for closing it is not simple, even including an algorithm to prevent it opening if it is calculated to be stressed according to a model.
It appears that the CREC has a redesigned coolant pump. We would hope that this would be more reliable that the one in the very early engines but
@arad85 has had his leak!