Alfa Romeo ‘Nord’ Twin cam. In 1949, only one in every ninety-six Italians owned a car but by 1963, that ratio was one in eleven! In these years, Alfa was looking to boost sales and survive the post-war years tough climate. They set about designing a series of cars that would turn the small volume manufacturer into a mass production powerhouse. That aim resulted in the Giulietta, a car that combined a sublime monocoque chassis, rear wheel drive and coil over suspension, with Bertone (coupe) bodywork. Underneath the bonnet featured a new engine. An engine that would revolutionise the automotive world.
Not much thought is given to the origin of todays short stroke, twin cam, four cylinder engines that are fitted to just about everything from minibuses to sports cars. If you think back, there were Cosworth’s, Lotus’, Fiat’s and even Honda VTECs but before all of these engines there was the Alfa Romeo twin cam.
Many High end car makers, like Bugatti, Mercedes-Benz, Peugeot and Alfa themselves had created double overhead cam engines before the ‘Nord’ engine but, Alfa combined a short stroke and a small capacity, then placed them in a relatively affordable car. This is what separates the ‘nord’ from previous cars. I know there are British car guys screaming ‘MG!’ at the screen but Twin-cam MGA’s came a few years later and was an adaptation of the old long stroke B-series. It wasn't considered reliable and was then dropped after only two years, the MGB soldiering on with a pushrod engine until 1980(!)
First seen in 1954, the Alfa Romeo Twin Cam engine (often referred to as ‘Nord’) lasted 40 years of production. Ranging from a 1290cc (56bhp) back in 1954 to a 1962cc (148bhp) in 1994 (not including later twin spark/16v variants).
Take a look at some of the advanced features this little engine brought to 1954;
• Aluminium alloy block with cast-iron wet liners featuring a large finned oil sump
• Forged Steel Crankshaft
• Aluminium alloy cylinder with hemispherical chambers
• Two valves per cylinder (sodium-cooled exhaust valves and Stellite valve seats)
• Inlet & Exhaust valves facing at an angle of 80 degrees
• Double overhead camshafts with dual row timing chain
With specs like this you can see why classic Alfa Romeo’s have such an enormous following and desirability! At ClementandBoggis we’ve been tinkering with this great engine ourselves - ours is an early Giulia 1300cc engine. One of the challenges of working with an Aluminium Alloy block, no matter what make, is the reaction between steel components and the Alloy. If you've ever had the scary prospect of removing a corroded bolt or stud from an alloy block then you know real stress. Not only does the reaction ‘corrosion weld’ itself, it makes steel brittle over time. The amount of work to drilling out a broken head stud or bolt deep in the casting makes anyone’s skin crawl. This is where IReOx comes in handy. IReOx gets into that thread and removes corrosion, increasing your chances of removing the stud/bolt without harm. It’s so engine friendly that before we dismantled our ‘nord’ for rebuild, we dipped the hole block and head into a tank of IReOx. We fully degreased the components first and then made a tank of 1 part IReOx to 20 parts Water. The solution worked its way into every crevice, every oil and water gallery removing any rust it could find. For the best results, we left the whole thing to get to work for two weeks, turning the components every couple of days to remove any air pockets and give the solution a mix. After two weeks, the solution had done a terrific job of cleaning up the old engine, which had been a bit of a barn find and hadn't run in many years.
Reasons to ‘IReOx’ an engine.
IReOx gets into every crevice and gallery, removing corrosion and limescale damage as it goes.
IReOx, unlike aggressive solvent and other acid based rust removers doesn't damage your rubber seals! In fact, its safe to use on just about any metal and is safe to dispose of! (though do bear in mind any suspended contaminants once its done its job)
IReOx’ing your engine prior to disassembly (in particular, engines that have been dormant for a while) can actually remove rust from piston rings. This Rust can cause nasty scraping and gouging of your cylinder bores when you come to remove the Pistons manually.
If you have cylinder liners installed in your alloy block then let IReOx get into the casting and remove the steel-alloy ‘metallic welding’. If you can save the mating surfaces from any more damage you may save yourself a bundle of money not having to get the block casting machined and new liners machined.
IReOx can remove corrosion from the valve train, such as those pesky collets that wont come out. IReOx can also be used to prepare any components for a thermal or electro coating. These coating only work when the metal is spotless. This saves on any metal preparation cost such as blasting and acid dipping at machine shops.