Cylinder Head 205 - Degree DOHC Camshafts

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• published: 05 Jul 2014
• views: 97831

This video is all about establishing your valve timing baseline, and adjusting your camshafts to the manufacturer's spec. It's only ONE of several steps that should be performed when you're assembling your engine on an engine stand. Establishing these conditions with accuracy while your engine installed in the car is a near-impossibility, and the reason why... is demonstrated in this video. There are several challenges to overcome when performing these procedures on a 4gxx series Mitsubishi engine, and they're all defeated here. The cylinder head used in this video is a J1 spec '92 Hyundai Elantra small-combustion chamber head which has had several valve jobs and has been resurfaced multiple times by budget engine remanufacturers who didn't care about quality control, as well as performance shops who do. It has had no less than .040" removed from the head gasket surface, the valves are recessed because of all the valve jobs performed, and at some point when it was cut, it wasn't level. Removing material from the deck surface will change the installed camshaft centerline, and that will change your engine's valve timing events even if all other parts remain the same. I would claim this is a multi-part video except that I've got the videos broken up by topic already, and this one is all about setting your cams to the manufacturer's specification. It is not the end of testing that will be performed with these tools. The basics concerning the process and tool fabrication are covered here. Further discussion on this topic concerning the effects of advancing or retarding camshafts from spec, and for checking your valve clearance will be in the videos that follow. I had to end this video after the manufacturer's spec was achieved to make it easier to digest, and because it would have created a video greater than one hour in length despite the break-neck speeds that things happen here on Jafromobile. Where your cams are set determine how the swept volume of the combustion chamber gets used. The information on the manufacturer's spec sheet is their recommendation for baseline settings that will help you get the most out of those camshafts. Whether or not your engine can operate with those specifications without additional hardware or without causing a catastrophic failure will be expanded upon in Cylinder Head 206. The next video should be used as a companion to this video because establishing the manufacturer's baseline is not the end of the assembly or testing process. It's only half the battle. Should you be lucky enough to find your combination of parts allow your camshafts to fit and requires no additional adjustment after assembly, the steps in this video and in Cylinder Head 206 should still be performed if you are doing the assembly yourself. Failure to inspect these variables may lead to a tuning nightmare once the engine is back in the car, hard starts, or worse... bent valves and damaged wrist pins. Making these tools and performing these steps will give you the peace of mind to know with certainty that your engine is operating safely at its peak performance.