Posted by Alan Bowes on April 07, 1999 at 13:58:22:
In Reply to: Ask and ye shall receive...Speed Equip. posted by David on April 06, 1999 at 18:00:57:
I must admit to pausing for a while over the goodies in the latest VPW literature. Maybe one of these days I'll build up another hot flathead. So far my flathead hot-rodding efforts have been limited to Ford flathead V8s, but the same principles apply.
My only advice to any budding Dodge rodders is to do it ALL if you're going to do it. Let me elaborate a bit:
If you're going to increase the CFM rating by installing two carbs, you'll need the high-performance cam to allow the engine to pump enough air/fuel through it to keep adequate air velocity through the carbs. Exhaust headers will also help a bit in that department. I don't know what the passage diameter is on the headers, but this will have an effect on where they will help or hinder extraction at different RPM ranges. I suppose you might even want to mill the heads a touch and do a bit of flow matching in the ports. The high-temp valves/seats are a good idea. The stronger valve springs are nice, although this still won't be a "high-speed" engine and valve float probably won't be a big issue. However, it's still a good idea to have some "quicker" springs to follow a cam grind that might create some more rapid valve movements.
Of course, it won't do any good to boost the HP and RPM if the whole thing is going to act as a piston launching platform, so be SURE to have a racing shop rework the CONNECTING RODS, including magnafluxing, balancing, resizing both ends, new rod bolts (preferably high-strength bolts), cleaning up the forging, and shot-peening. And you'll want to align-bore the engine, turn and balance the crank, bore and hone the cylinders, replace the pistons/pins/bushings/rings, install a new oil pump, and balance the whole reciprocating assembly. An electronic ignition would be a nice touch. And you could shave the heads a bit, making sure that you'll have adequate valve clearance, allowing for a little float (which should be minimal with the new heavy-duty valve springs, but allow for it anyway).
Now that you have an engine that puts out significantly more HP (and it will be significant), remember that it will be at a higher RPM range and that you may lose some bottom-end power with this setup, depending to a large degree (so to speak) on the cam grind. However, this does not necessarily mean that it will be worse for off-roading, but rather that you may have to stay in lower gears longer to keep the engine in its optimum hp/torque curves. Gearing is the key to matching engine hp/torque curves to different applications.
VPW carries all of the other nice new parts that you'll need for a total engine rebuild, so you can probably do a blueprint job with one-stop shopping for the parts, plus a good speed shop for the machine work.
In summary, don't do things halfway and simply bolt on all of these nice things...do a proper job on the engine and you'll enjoy the rush of adrenaline from the new-found power for a lot more years.
Ah, yes, I love the smell of smoking tires...
Have fun,
Alan