What is the difference between a stroker engine and a normal engine

Although the precautions mentioned earlier can be undertaken, the risk of collisions within the engine are inherently increased. A common issue is the crank journals contacting oil rails lying between the crankshaft and the oil pan. A stroker kit is a relatively complex modification intended only for the most handy of petrolheads.

The ability to disassemble an engine, replace the key components and then put it all back together is not for the faint of heart, but the power gains associated with a stroker kit are thoroughly respected in the muscle car world.

So if you have the mechanical knowledge and the hardware to go about it, a stroker kit may be the key to a whole new stable of horses. Have you ever thought about a stroker kit for your car? Or does your car feature such a kit and if so, how much more power has it led to? Comment with your experiences below! Please confirm you agree to the use of tracking cookies as outlined in the Cookies Policy. Sign in or register. Michael Fernie 5 years ago. It works in the opposite direction, too.

Let's say your aim is efficiency rather than power. The best engine to have, then, would be one with a small bore and a long stroke. Well, it's a bit more complicated than the power equation, but it involves surface area. Basically, the more surface area a cylinder has during its combustion, the less energy is lost to heat, resulting in a more efficient cycle.

These are just simple explanations, though. If you want to learn all there is to know about bore and stroke, check out Fenske's video above. To find overlap O :. As stroke increases, the overlap in the areas of circles defined by the main and rod journal diameters decreases. Less overlap reduces crank strength and rigidity. The amount of acceptable overlap is determined by the strength of the crank material, the engine's power output, and its intended use.

When regrinding a finished crank into a stroker, care must be taken not to run into the internal oil passages. Attempts at welding the original passage shut and drilling a new passage usually prove unsuccessful; eventually the crank cracks in the fillet area. Piston Problems As we've seen, increasing the stroke and making no other changes usually causes the piston to stick out the top of the block. Shorter connecting rods are usually not the best solution; rather, pistons with raised pin heights help move the top of the piston back down below the deck.

The pistons can be made shorter but only to a point-there must be room for the ring package above the piston pin. Various devices allow running the oil ring through the pinhole area, and there are even two-ring pistons; while acceptable for regularly torn-down race engines, these solutions aren't recommended for long-term street use. You could also go to a smaller diameter pin and bush the rod-but "a smaller stick breaks easier.

Also, the bottom of the piston must clear the crank throw at BDC. Counterweight height C is determined primarily by the rod length for a given amount of stroke:.

If a clearance problem exists, either the crank counterweight or the piston can be remachined. Do not remachine the counterweight in a circular arc or there will be insufficient weight left for balancing purposes.

Instead, the counterweight must be cam-ground for clearance by an experienced custom crank shop. As the stroke increases, the rod needs to get correspondingly longer to maintain the optimum rod ratio-but the longer the stroke, the less room there is to fit a longer rod.

Too-short rods increase cylinder wall thrust-loading and restrict maximum rpm potential. Bottom line: On a big stroker, use as long a rod as you can get away with, based on the smallest practical piston.

When we increase stroke, we take the piston deeper in the cylinder bore, which increases displacement. Because mechanical advantage or leverage comes with stroke, torque does too. Think of stroke as you would using a breaker bar instead of a ratchet to remove a stubborn bolt. The longer the lever--or stroke--the greater the mechanical advantage. We can stroke an engine in a number of ways. One way is to offset-grind the crankshaft rod journals, adding some meat at the top of the rod journal, then grinding the journal true again.

This adds stroke, even if it's just 0. This might not seem like much, but it can add up to significant displacement increases. Remember, Ford stroked the 0. Another way to achieve stroke is to machine a larger crankshaft down to fit a smaller block. The ci stroker is designed this way. The same is true for the ci stroker from a W block. A M crankshaft is machined down to fit the W block. Stroker kits often go even further, using Chrysler or Chevrolet connecting rods to achieve stroke.