The BMW head can come with four different cams. I don’t Know exactly which ones come with which heads but i do know which ones i want. I also seem to remember that the first head i did the correct cams were in it already and it was a 93 k1100 LT head. These cams have 254 duration and thats on the cam not accounting for lash.they have .313 lift they are timed at 106/106
The reason i chose these cams is the computer showed these cams to deliver the torque peak at 4500 rpm. The peak power is supposed to be 110 to 115 thats about 90 hp at the wheels. Just to be clear. The car this engine was going into is racing for two days at a time and has to withstand accelerating at full throttle for hours on end. The rpm limit we put on it is 6500 RPM One thing i know from racing other cars is high RPM’s is an engine killer. The mini is especially suseptable to bearing wear at high RPM’s because of its three bearing design. So we are working our way up in power to preserve the engine and the rest of the running gear. Theres more power at the top end if we want it.
Next up in the cams is the 284 RS cams these are timed at 102/106 .343 lift the intake is advanced 4 degrees this would boost top end power but pulls a lot of power out of the lower end 1000-4000 rpm. I may do this on the race car one day but the car is already fast.
The race mini when it had the five port head would come into the pits just blistering hot. Heat would just be pouring of of it. You couldn’t touch anything it was just super hot. The twincam is the opposite it is cool. So cool in fact that you can touch the valve cover right off the track. I am changing the thermostat to a 180 degree one just because the fuel injection won’t fully get out of cold start mode till its over 160 degrees.
These cams idle well but we are still tuning it and have not spent anytime on the lower rpms. Without any tuning it idles at 1000 rpm with a little lope. The engine pulls nicely straight from idle but it does stumble a bit at 3000 more tuning should fix that.
There are other cams other than the LT and RS and there will be more to come on those because i am having them plotted soon.