SDC CNC MACHINED MAIN CAPS - MOPAR
For the serious BB Mopar engine builders out there, BCR products billet machined main caps.
All BB Dodge motors have a serious problem in the main webbing and cap area if you use cast iron heads and or make 500 plus horsepower. The heads have a poorly designed quench area and no matter what you do to modify them they tend to pre-ignite or detonate the air fuel mixture. This in the long run tends to crack blocks and cranks then it eventually will break the main caps themselves. I have been building BB Mopars for nearly twenty years and kept running into this problem. What I found out was if I built a high HP Mopar with aluminum rods it always lived a longer life than a steel rod motor. What I found is the rod acted as sort of a dead blow hammer and took up the shock of the detonation and or in the case of aluminum head motors the combustion shock and did not transfer it to the mains as badly.
Most people especially street strip guys do not want to run an aluminum rod due to the duty cycle being so short on them. I found if you use an aluminum main cap that it does the same thing and you can then run the steel rods and extend the life and the output ability of all BB Mopars. Since using aluminum caps the percentage of failure of any of the above mentioned components went down by at least 80%. As a side note I am using the same caps on my Super Gas motor now for the past 11 seasons with no re line bore. The other advantage is they almost eliminate what is called cap walking. The movement of the caps that can be seen on the bottom of the caps when removed that looks like a rough surface transferred to the caps.
Along with input from many top engine builders from around North America and of all places Sweden I redesigned my original caps to create what I and many others feel is the ultimate main cap. There are others who build main caps, but beware of the inherent design flaws. Problem with their caps is they were made out of plate aluminum and they didn't fit very well and were poorly machined. These caps are made of a special heat treated aluminum Alloy. There’s also had recessed holes for the main studs and you had to use a special ARP stud kit with a twelve point head. So if you had a Milodon stud kit with six point heads you had to go and buy another set because you could not get a socket down in the holes to torque them. There’s you had to modify the rear main seal plate to fit the # 5 cap. I addressed all these issues and I feel have came up with a better system. These are especially suited for those who are now using the new Edelbrock aluminum heads as it is easy now to make large Horsepower figures using them. If you are going to make some big numbers with your stock block you will need these to ensure a long life out of the stock components. These caps have now been successfully run in motors making in excess of 700 HP. These will fit all 383, 400, 413 and 440 stock blocks with two bolt mains. These require line boring of block when installing.