Slant 6 Turbo 68Dart Project
So I found an intake and a friend has a 650cfm mighty demon which are setup for blow thru from the factory but with a cam and springs will the turbo slant be able to handle that big of a carb?
I don't know how much you know about turbochargers and how they affect slant sixes, but the standard thinking of: "more cam is better" just doesn't apply to these boosted motors.
My engine is a virtual clone of two highly-successful boosted slants that each make a little over 500 horsepower, and they do it with camshafts that idle just like a stock cam. That means they have very little overlap, which is "the plan." The fact is, it doesn't do much good to run 25 pounds of boost if you're just going to blow it all out the exhaust valve on overlap.
That means, the cams that seem to work best in these boosted engines, have very conservative specs as regards duration. My cam is pretty much a copy of those 500-horsepower engines' cams. It has 210-degrees duration (both intake and exhaust,) at .050"-lift and is ground with 115-degrees of lobe separation. Bigger numbers in lobe separation help ensure less overlap. Lift is a problem with short-duration cams, and about .484" is the most you can get with a cam like this one. So, some 1.6:1 rockers are a big help, here, pushing max-lift to over.500". They are expensive to buy, but you can make your own by slicing about .100" out of the stock 1.5 arm and welding it back together. See pics...
One big help in the camshaft department is the fact that these motors never are asked to turn over 5,500 rpm. They just won't perform well beyond that. That means that not much valve spring is needed to control the valve-event, so a flat-tappet cam can last a long time. Also, since there is not a lot of rpm necessary to make maximum power, the requirements on the ignition-system are not too demanding. I use a stock Mopar electronic distributor and an MSD 6-AL and have, to my knowledge, never experienced a misfire or any kind of ignition failure.
I think both of those 500 horsepower engines I make reference to, use Holley 650 4bbl. DP's.
That's not to say their road manners or mileage are good, but, they sure are
F-A-S-T!!!! :cheers:
