Hi Mosey, I built the Silver Bullet about 10 yrs ago and it has been a good runner. I built the radiator to Bob's design and it has a 4 blade fan for cooling which it doesn't do very well. Mine will get quite hot (200 degrees) fairly quickly. I think the radiator is of sufficient size but the fan doesn't pull much air. A good multi blade fan that is shrouded would help a great deal.
The water pump is built to Bob's specs also using pinion stock with an o-ring between the pulley and housing for sealing which works alright. It seems to move plenty of coolant as my coolant lines are clear and you can see the coolant flow. I don't normally run my engine long, maybe for 5-8 mins before shutting off. The Silver Bullet was my first IC engine build and remains one of my favorites. I hope you will enjoy yours as much as I have mine. Dave
Dave,
Been thinking..too late for this head, but I've been wondering about finning the head, now I have an excuse, to cool it. Humm?
Mosey