70 dart swinger slant turbo build and mild restoration
Well bill I think your right again I think it's gonna be a carb over fuel injection 1st the ez-efi system is a 1 bar system so it runs only for normally aspirated engines there's other alternatives to run but I don't know if the headache and initial investment is gonna outweigh a carb. Yea it would be nice to be able to have a car that fires up and idles perfectly but that's not why I have the car if I wanted a nice idle I would just get in my new suburban with heated seats and ac so yea it maybe be a little old school but with a data logger and msd it will do what I need it to do which is make a funny noise and haul butt
The nice thing about these turbo motors is the camshaft, and the way it affects the, uh, "personallity" of the engine it's in. The normal modus operandus for a horsepower-effective cam in a naturally-aspirated engine is to employ high lift and long duration paramaters, to achieve high output for.ultimately, a fast car. These necessary specs for that cam, manifest themselves is some negative ways, such as premature cam-lobe wear due to the necessarily-aggressive nature of the lobe profile, coupled with the high spring pressures necesssary to control the high-rpm valve-event, a ragged idle, not much low-end torque, and a "peaky" torque curve. They also impose additional stress on the mixture tuning (carb) due to the overlap encountered.
Turbo camshafts have some significant advantages over the conventional, "full-race" version that usually goes along with a necessarily-radical profile,
naturally-aspirated cam. First off, turbo engines cannot tolerate much overlap, so, the lobe profile must employ short duration. This has the effect of making the idle very much like the idle of a stock engine, and the low-end torque, plentiful. Driveability benefits greatly from this. If you choose not to get into boost, it's pretty much like driving a stock engine. Another positive aspect of these turbo cams is that they don't require a lot in terms of valve spring presssure because the rpm-limit is only about 5,500, and that is low enough so as not to require valve spring pressure that can cause a cam to go "flat," prematurely. This is important because roller cams are REALLY hard-to-get for slant sixes, primarely because,
nobody makes a "blank" for a slant 6 roller-tappet cam. It can be done, of course, but it's outrageously expensive and basically, uneccessarily, given the easy life of a turbo cam (flat tappet) in one of these boosted engines. So, with a short, break-in and some ZDDP additive, a mild, flat-tappet cam can live a (cheap) long, healthy life in a 225 turbo motor. My cam has these (very mild) specs: 210-degrees duration at .050"-lift, ground with 215-degrees of lobe separartion (for less overlap,) and .484" of lift. Stock rocker arms (1.5:1 ratio) and stock pushrods.
It idles and drives with the impeccable manners of a stock motor, but comes on like gangbusters in a Jekyll/Hyde transformation, when called upon for performance.
At (only) 15 pounds of boost, it makes approximately 354 horsepower, which is just about the limit for a full-race naturally-aspirated 225, with its attendant, ragged-idle and cranky road manners. The turbo motor also LIKES a 2.76:1 rear end ratio, which gives you both hiway gears (no overdrive needed,) and the optimum drag strip gearing.... no 4.56 needed here, so the 8.25" ring gear rear (cheap and plentiful in junkyards) is the way to go.
Hope this helps...
The pictures are of some home-brewed 1.6:1 ratio rockers I made. They will give me over .500" of lift at the valve with my .484"-lift cam (stock ratio is 1.50:1.)
