What Would I Need
I have a 1969 Dart 340, forged crank and forged flat top pistons, H beam rods, Hughes solid 5256AS cam, 750 Holley, J Heads light porting, rpm air gap. What would i need to do a Paxton blower on my car. i have MP Chrome Box and Distributor, would i need all MSD Stuff? What do i need for a carb? Do you recommend a bonnet or the big box piece the carburetor goes inside? Should i run Meth/water injection? i have a Mech. Fuel Pump now i am figuring ill probably need an electric one. Also how difficult is it to tune a blown carb motor? should i figure on putting in an A/F gauge? Sorry for all the questions, new to forced induction, any help would be great or some links to some build threads close to my situation.
Thanks in advance, Chris
Ideally, you'd need forged pistons that provided an 8.50-9:1 compression ratio, a Paxton blower and its mounting plate, a carb (600-750 cfm) that has been modified to "blow-thru" status, a bottom crank pulley to drive the supercharger (serprntine system, probably) and an idler pulley and mount for it. A serpentine belt of the right dimensions.... Cast pistons are OK IF you limit boost levels to 4 0or 5 pounds...
Also, depending on how much boost you want to run, a meth/water injector might be necessary. Up to about 7 pounds, you might get by without one, on pump gas. Over that, I'd bet you'd need one for staving off detonation.
MSD makes an ignition system for boosted cars that will retard your ignition timing with a dash-mounted knob, that gives you the opportunity to control timing "retard" either 1, 2, or 3-degrees per pound of boost, up to 15 degrees; your choice. This would seem to be a plus for pump gas users. The system is called an "MSD Boostmaster" and, as I understand it, it is an analog system and totally unlike the multiple spark discharge systems such as a 7-AL. I have one on my supercharged car, and, the output is said to be in the 42,000-volt range, which works just fine on my 10-pound, Vortech-boosted 360 Magnum.
You'll need a carb "bonnet" and plumbing from the blower to the intercooler or carb bonnet. I don't know anything about the enclosures that are used as an alternative to a "bonnet." Sorry.
An intercooler would be unnecessary below 10 pounds of boost, IMHO.
You'll need a boost gauge...
Blown engines like big exhaust.... at least 2 1/2", but, preferably 3" or more....
Get used to buying PREMIUM gas at the pump....
Speaking of gas, you'll likely need a fuel-system makeover. How extensive will depend on the boost level you choose.
You will probably need a new cam; supercharged and turbocharged engines seem to run best (fastest) with cams that have a lot of lift, but not much duration. Not much duration = 210-215 @ .050". Also, they like lobe center spacing in the 114-degree range. See... a new cam...
Hope this helps!!!:read2:
PS, remember, 8 pounds of boost increases your 340 (340 + 170) = to 510 cubes, theoretically...:cheers:
