LCJUTILA.
If you don't have a copy of "How to Power Tune MGB 4-Cylinder Engines" by Peter Burgess, then you need to get a copy. It is currently the definitive work on building up the B Series motors and does give very good advice on home porting of a street engine.
Most of the performance oriented components such as heavy duty springs and rim-flow oversize valves are wasted on a street driven engine and will reduce engine life. Performance is all about making compromises. Even something as benign sounding as a three angle valve grind reduces the longevity of the head as the narrow seat faces created for increase flow will errode faster than the original wider seating surface.
Just something to think about.
There is a lot of performance left on the table due to the head manufacturing process, so it is very worthwhile doing a basic smoothing and cleanup. Above that the cost/benefit starts to decrease rapidly for an engine that will only be run up to the 5,000 rpm range on the street.
Kelvin Dodd
Global Sourcing Engineer
Moss Motors, Ltd.
Helpful Links:
Code of ConductFAQsDisclaimer: Working on automobiles is inherently dangerous. Moss Motors, Ltd. is not liable for injury or damage due to incorrect installation or use of their products. All products are sold with the understanding that the safe and proper installation and use of the products is the customer’s responsibility. Follow factory workshop manual procedures and instructions, but use current shop safety standards and common sense. Some tasks will require professional advice or services which Moss Motors cannot provide.