318 mod engine

[modracr41]

Alright mopar fans, I need some input here. I am building a mod to run on a 1/4 mi dirt track. The track here starts out slick for the hot laps, then for the heat races it gets tacky. By the time the feature comes around, it is dry-slick. My question is this: Could a 318 be built to run well in this application? I know that it is hard to find aftermarket pistons for a 318 unless you use flat tops. I also want to run alcohol. Any input would be greatly appreciated. Thanks.....see ya at the track.

[340king]

I have often wondered about the viability of the venerable 318 in that application. I have a friend in Oklahoma that tried a 318. He used Probe pistons, W-2 heads, a roller cam and a 904 direct drive trans. It was undriveable. The engine was pretty much like a two stroke. It would bog up to 4,500rpm, then zoom up to 8,500 rpm without hesitation. It looked like it would have been a better combo without as much high zoot stuff. I modeled it on the computer and it reacted just like he described it. It was violently peaky above 4,500 rpm with nearly a 100 hp jump in just 500 or so rpm.

One of the ideas that some very successful racers have used is to build a milder engine, giving up a little in the heats, and gaining in the features. It is a dicey thing to do. Too little hp and you can't compete, too much and all you do is blow the tires off. In my mind the small displacement engine does provide a little more cushion when trying to follow a marginal traction track surface. It seems to have a lesser degree of overshoot. If you blow off the tires, it recovers faster. I have liked the flat top pistoned 340's for dry slick applications. They have enough snot to keep you in the hunt during a heat race and are smooth enough to hook well on dry slick.

I imagine the 318 could be just as well suited if you wind it a little more. Some drivers claim that you can gear down on dry slick and follow the track better. It just puts a little more stress on the engine. This can be especially true with high compression engines. If you avoid the rpm where peak torque is made, it may be easier to drive. Again, this can be hard on parts and the only racers I know that try it are in Late Models. The other reason that they like this is that the reduced corner speed lugs the car down in the corners. If you look at it from the perspective of how can I maximize my ability to hook up to a dry slick track, a small displacement high winding engine may do the trick.

[modracr41]

Thanks for the input. I, too, have wondered how a 318 would perform since the availability is so great. However, I have resolved to use the 360 for my particular application. A friend of mine, crackerg, had one go bad, but it ran strong for 3 seasons before shooting craps. I think that the external weight had something to do with the crank and block failure. Thanks again. .........See ya at the track.