When they build a turbo charged slant 6 engine, what RPM will they comfortably max out at? What is the safest, maximum RPM for a 4" crank?
probrably the same as it is with out turbo. around 4,000 the power curve drops off. these engines are not designed to rev. You do not need to have a high revving engine to successfully have turbo. the turbo has to be sized properly for the application.
Wouldn't be difficult to weld to a cast-iron exhaust manifold? What do you do?-heat it up to glowing red, weld, and then slow down the cooling down process..?
I have seen it in a few write ups and from FABO members that they cut the stock flange off and weld the turbo flange on. looks easy actually...
Everything that I have ever heard of welding to that type of metal (sometimes incorrectly referred to as pig-iron) said that it was difficult.
Looks easy seriously. As for worrying about cracks heat stress the turbo is not suspended off the flange to reduce the risk of stress cracking. a bracket is made to support the turbo to the block. Although I would like to point out that even if you pony up the 1000 bucks for a ceramic coated turbo header it may crack as well might as well make it out of something that is a dime a dozen so...really this worry of your's about the difficulty of welding onto cast iron is nothing to worry about
They do it for rare, matching-numbers blocks and heads on older cars, but Tulsa Welding recommended against it as a general principal.
Anything can be welded. It is done everyday.