Proton Wira 1.6XLi Important mods - Phenolic Spacers, Metal Gaskets & Aluminium Crankshaft Pulleys

I recently fixed up a dark purple 1998 Proton Wira 1.6XLi automatic that belonged to my late father. It basically needed some TLC after being left under-utillized (since his passing). It was leaking engine oil as its fiber based cylinder head gasket deteriorated over the years. The only mods done to it was a set of 15inch wheels and 195/50/15 tyres.

The thing about fiber based gaskets is that they never last. The fiber would actually slowly deteriorates over the years and the residue actually gets eaten during combustion or if you're unlucky, like in this case, the fiber pieces get into the cooling system and clog up the cylinder head and radiator. It caused the car to overheat after being used for about an hour. Everytime you get into a traffic jam the temperature would slowly rise. So there was a need for a cylinder head rebuild. And a thorough flushing of the radiator.

So once your mechanic pulls off the cylinder head to rebuild, the best option for anyone who wants to keep the engine running well longer than any fiber based gasket is to opt for a metal gasket. This is actually an extra RM200.00 option over an above the RM200.00 needed to buy the fiber gasket/overhaul set. I opted for a slightly thicker 1.5mm Mitsubishi metal gasket set as I wanted the car to be reliable with a slight skimming of the cylinder head. Please also note that the Mitsubishi 4G93 gasket can be used for the 4G92 1.6 engine too.

There is a 0.8mm option for those who would want to increase the compression far beyond the standard 10.0:1 compression ratio. With the skimmed head, my mechanic reckoned that the CR was now 10.2:1 and not something in the 11:1 CR. That higher ratio would be good (and is what my Subaru Impreza 1.6TS now runs from its standard 10:1) for making the engine produce more horsepower and throttle response than what my rebuilt head would produce, but I was aiming for reliability here instead of all out horsepower here. It IS just a Wira 1.6.

But I wasn't without my mechanic's usual bag of tricks. He had something up his sleeves in the form of phenolic manifold spacer for the 1.6liter 4 cylinder engine. It is basically a piece of heat resistant fiber that blocks off the engine heat from the intake manifold. It is that white piece sandwiched between the inlet manifold and the cylinder head in the photo below.

Here's how it works - from GrimmSpeed.com (a US based site where I bought a set of spacers for my Impreza 1.6TS(which is another story for another time)

• The intake air in your engine travels through the airbox into the turbo, then into the aluminum intake manifold. The air exits the intake manifold and goes directly into the engine.
• While the intake air is within the intake manifold it picks up alot of heat from the aluminum intake manifold. This added heat reduces air density thus reducing engine power capabilities.
• In stock form your engine has a steel gasket between the intake manifold and engine which allows the heat from the engine to quickly transfer into the intake manifold. By replacing this steel gasket with the GrimmSpeed™ Phenolic Spacer you are greatly reducing the transfer of engine heat into the intake manifold.
• Phenolic Spacers are able to withstand 500+ degrees F. Subaru engines run at the hotter end of operation around 200 degrees F, so the Phenolic Spacer is well within its max running temperature. GrimmSpeed™ has tested that it is also safe to run race fuel, E85, and methanol with the Phenolic Spacers.
• The Phenolic Spacer will conduct 300-900 times less heat than the oem steel gasket.

AND...it basically does this:

• Greatly reduces the transer of heat from engine to intake manifold thus reducing heat soak.
• One of a kind true Phenolic material, not cutting board material like others.
• The cooler your intake temperature is the denser the air is which leads to more power
• For every 5 degree reduction in temperature, increases power by 1%.
• The cooler and denser the intake air that the engine sucks in, increases the amount of air that can be mixed with fuel thus increasing efficiency.

So the Wira's mechanic, a chap named Henry Khoo, the proprietor of KS Auto in Ulu Klang has actually conducted some research and came up with his own set of phenolic spacers for most of the cars in Malaysia. Custom cut of course. And it is on this Proton Wira 1.6XLi.

Now add this and an AROSPEED lightweight aluminium pulley (costing around RM250.00 and over 1.5kg lighter) things get pretty fun. Yes, this aluminium pulley is actually a very, very good mod for the Wira. It actually releases extra power that was lost from the heavy standard crankshaft pulley. The lightweight aluminium pulley decreases rotational mass making the engine rev faster than before. It basically shifts the power band a little lower and is actually very good to have in the Wira 1.6 automatic. This is because the 4 speed automatic's gearing is a little screwed up. There is a noticeable gap in the powerband that is (slightly) corrected by the pulley. As the revs come in quicker, the powerband feels smoother. But do check out the spelling for 'hardened' is only spelt 'harden'. Grammar isn't a priority around here, especially even when the Malaysian Ministry of Defence uses Google to translate Bahasa Malaysia into English. So what is a little mistake on an aluminium pulley?

Now everything else for the time being was left stock with the exception of an Ultra Racing 4 point front strut bar (which does offer some improvement in terms of handling - but not a lot). But I do believe in keeping things simple with an urban runabout. You need the reliability and the ease of driving in city traffic. This Proton Wira 1.6Xli exemplifies it. Quite well actually as the standard 0-100km/h time for this car was 12.5seconds or thereabouts. The standard car did this with about 110bhp and it is actually pretty good for a 1.6liter car which only weighs 1,090kg (according to the manual)This one now does it in the low 9seconds (with some other smaller tweaks to the stock fuel regulator, air-flow and ignition timing) . All for an investment of around RM1,500.00. Which is pretty good for a lightly modded automatic.