Shelby Aluminum

[Keithc8]

Stellcomp we consider all of the things you mentioned and more. When you do this everyday for over 20 years you have looked at all of the things you ask about. There are a lot of things that you ask that are basic questions you need to know with any engine build. It would be a lot easier to answer the questions over the phone or in person. Ther are a lot of these questions that any engine builder would not tell you because of the time it take to learn them.
All of the things you mentioned are good questions. The flow is checked at 28" of water on an 4.250 bore with a radius entry. You of course have to consider that the FE intake port is shorter than normal because of the head design but we still check the size of the port for comparison. You always worry about low and mid range flow depending on the application. You well know that on race engines you may not want real good low flow because the exhaust will suck a lot of the intake charge out the exhaust on over lap but you also want to have some to get the intake charge started. Like everything else there is a happy medium. I plan on answering a lot of the questions you have when I get ready to write my FE engine book in the future[HaHa].
I would not be very smart if I had worked on these engines and heads for 20 years and not learned something. We seem to do a pretty good job with the heads and engines because we have some of the fastest ones in the country.
You can be assured we have a handle on all of the things you ask I'm not sure I want to tell them to everyone, this is one of the reasons they buy engines from us.
We have done chamber work on the FE head and we use the Edelbrock 428 casting when we do this because there is a lot more material to work with. We unshroud the spark plug and the valves with better angle of entry to the chamber from the valve job than the 427 machined casting. This is only needed when you want max power. We weld up chambers, intake and exhaust runners and move them all over the place. There is not much we have not done with these heads, that is why about every NHRA record held with a FE has our heads, well just about all the fast ones in the country have our heads. Back cutting the valves is pretty common and this needs to be done with different angles depending on the valve job angles. We have about 10 different valve jobs we use on the heads depending on the application and they all get different angles on the valves. You will always play with different style valves as well. This all just depends on how much they want to spend. WE can do FE heads that flow 400cfm intake and 300cfm exhaust at .900 lift if that is what some one wants. There is always a trade of with flow. We have wet flowed some of the heads to check how the mixture hits the chamber and the cylinder. We also check the swirl as well. When we find something that makes good power we will make notes and mark that program and work from there. The problem with the FE is that the pushrods go through the intake and this is a restriction in the intake manifold. We will weld up the pushrod holes and move the pushrods over and open up the intake in this area. This requires off set rockers and lifters which is used often in other engines. The engine does not know what it is and we have fixed most of the short comings of the FE engine.
We could get into the crappy factory valve train and how we fix that problem but I do not weant to tell everything. We have the Super Stock engines where we are shifting at 8000rpms and crossing at 8400rpms. Most people thought you would never be able to do this with an FE and the all out race engines we have turning 8600rpms. This is no problem with a small block but most people can not do it with an FE.
What most people do not understand is that we are bringing race technology down to the nice street engines and with the new parts available they are able to make some real nice power now. Thanks and good luck, Keith