After many years of delaying and misadvertising regarding Campro (namely SP4's) engine, our beloved Proton FINALLY came out with
the long-awaited valve-lifting engine; Campro CPS. A short brief about CPS which was developed and patented by Lotus Engineering, this engine uses two technologies to achieve the new higher output; camshaft profile switching system which enables a higher valve lift and an electronic VIM (Variable Intake Manifold). A longer intake manifold is used at low RPMs to
achieve slower air flow; this promotes better mixing with fuel. The short intake manifold allows more air in faster, which is beneficial at higher RPMs. Variable intake manifold benefits more low-speed torque than high-end power. Therefore it is very useful for saloons, which are heavier and heavier these days. The Siemens-VIM module is built from a durable hard plastic which able to reduce heat soak from the hot engine and light in weight.
The result is 125 horsepower (93kW) at 6,500rpm and 150Nm of torque at 4,500rpm . Since the Campro CPS engine output is higher than the non-CPS Campro, it has an additional water-to-oil cooler near the oil filter placement. It was reported before that Campro has a beyond-normal oil temperature issues if it is driven hard for a while; so an oil cooler is considered as a good add-on from Proton for the CPS. The service center says Proton recommend 10W-30 oil for CPS even though the manual booklet stated the common 20W-50. Are Proton too busy promoting the CPS until they forgot to update their recommended oil specification? Only god knows. Running thick oil in a new engine isn't clever. Tight tolerance engines need thin oil. Please don't say our ambient temperature is hot so we need a thick oil. Death Valley in California is hot, even hotter than our temperature here but nothing 30-weight oil can't handle.
Unfortunately, the
vtec-like feature is only on intake side while the exhaust side is still using the conventional camshaft. Compared to the systems in the Japanese models, Proton’s CPS VVT feature is a simpler mechanism without infinite variability; using an obselete 2-step concept, imagine like switch; it either
on or
off. The effectiveness of the cam-lifting feature is arguable. This is because the serious Campro torque-dip problem was solved solely using the IAFM* module alone
(* the vacuum-operated version of VIM). If you compare the power figure for Campro AIFM with Campro CPS, there's not much different in torque delivery, at least, not much to shout about. The only noticeable thing is CPS able to hold the power for much longer and yeilded an extra 15 ponies. Nevertheless, when compared to the base-Campro, the torque distribution from CPS is way better, or at least it look so on the dynosheet. The torque is higher, flatter and stays longer in every rpm range which surely tells that this is a rev-happy engine. It also gained the loss of high end power caused by the AIFM module. I'm not too confident this engine will perform well in Proton's upcoming MPV, the Exora, but it should perform lively in the lighter Satria Neo.
After many years of delaying and misadvertising regarding Campro (namely SP4's) engine, our beloved Proton FINALLY came out with the long-awaited valve-lifting engine; Campro CPS. A short brief about CPS which was developed and patented by Lotus Engineering, this engine uses two technologies to achieve the new higher output; camshaft profile switching system which enables a higher valve lift and an electronic VIM (Variable Intake Manifold). A longer intake manifold is used at low RPMs to
achieve slower air flow; this promotes better mixing with fuel. The short intake manifold allows more air in faster, which is beneficial at higher RPMs. Variable intake manifold benefits more low-speed torque than high-end power. Therefore it is very useful for saloons, which are heavier and heavier these days. The Siemens-VIM module is built from a durable hard plastic which able to reduce heat soak from the hot engine and light in weight.
The result is 125 horsepower (93kW) at 6,500rpm and 150Nm of torque at 4,500rpm . Since the Campro CPS engine output is higher than the non-CPS Campro, it has an additional water-to-oil cooler near the oil filter placement. It was reported before that Campro has a beyond-normal oil temperature issues if it is driven hard for a while; so an oil cooler is considered as a good add-on from Proton for the CPS. The service center says Proton recommend 10W-30 oil for CPS even though the manual booklet stated the common 20W-50. Are Proton too busy promoting the CPS until they forgot to update their recommended oil specification? Only god knows. Running thick oil in a new engine isn't clever. Tight tolerance engines need thin oil. Please don't say our ambient temperature is hot so we need a thick oil. Death Valley in California is hot, even hotter than our temperature here but nothing 30-weight oil can't handle.
Unfortunately, the vtec-like feature is only on intake side while the exhaust side is still using the conventional camshaft. Compared to the systems in the Japanese models, Proton’s CPS VVT feature is a simpler mechanism without infinite variability; using an obselete 2-step concept, imagine like switch; it either on or off. The effectiveness of the cam-lifting feature is arguable. This is because the serious Campro torque-dip problem was solved solely using the IAFM* module alone (* the vacuum-operated version of VIM). If you compare the power figure for Campro AIFM with Campro CPS, there's not much different in torque delivery, at least, not much to shout about. The only noticeable thing is CPS able to hold the power for much longer and yeilded an extra 15 ponies. Nevertheless, when compared to the base-Campro, the torque distribution from CPS is way better, or at least it look so on the dynosheet. The torque is higher, flatter and stays longer in every rpm range which surely tells that this is a rev-happy engine. It also gained the loss of high end power caused by the AIFM module. I'm not too confident this engine will perform well in Proton's upcoming MPV, the Exora, but it should perform lively in the lighter Satria Neo. 
CPS concept obsolete? Honda's original VTEC ran the same concept and those engines are still far from obsolete performance wise. I'm sure some Honda fans will take offense at that.
ReplyDeleteInfinite variable timing on itself will only change timing but does NOTHING to the cam profile and valve lift. Higher and lower rpm operations require DIFFERENT lift profiles for optimum performance.
The CPS system, like the original VTEC changes both timing and lift. If combined with an infinitely variable valve timing mechanism, it's the best possible system without resorting to more exotic and untested technologies such as cam-less valve control systems. Do this for both intake and exhaust and the result is the best conventional valve control system possible, though intake alone would still give excellent value and make the most gains per spent resource.
FYI Porsche engines have used a combination of CPS style mechanism of valve profile change and combined it with variable timing so they could vary lift, duration and timing.
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