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396 Big Block Chevy Stroker Build - Stock-Appearing Stroker 396

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396 Big Block Chevy Stroker Build Stock Looking Engine
396 Big Block Chevy Stroker Build Engine Build

Of all the big-block builds in this issue, this one will have the most limited appeal, and we know that. To summarize, this article shows the process Westside Performance went through to build a better-performing big-block Chevy that looks like a stock, 325hp 396. Most people building an engine from scratch or freshening up their old one would likely go for bigger displacement, aluminum heads, and so on. But some people want their engine to look as stock as possible, including cast-iron heads and intake, but built to its fullest potential. We can totally respect that, too. Though that particular build won't post the big numbers of an engine built with aftermarket parts, some creative thinking will get better performance than the stock engine could have hoped for.

Whether you want to build a stock-looking 396 is irrelevant. The most important concept to draw from this article is how to gain the most performance from the parts you have. Working within limitations that seem to restrict performance bore size and combustion chamber shape, for example, forces an engine builder to come up with creative ways to work around these confines to build an engine that's better than the sum of its parts. With that in mind, let's take a look at how Ted Toki, owner of Westside Performance, put together a 461ci big-block Chevy that still looks like a bone-stock 396.

The Starting Point
This engine was most likely an L-36 396 out of a fullsize Chevy circa '65 or '66. The bore and stroke were originally 4.094 x 3.76. It had 10.5:1 compression with oval-port, closed-chamber cylinder heads and a Quadrajet carburetor on top of a cast-iron intake manifold. These were rated at 325 net horsepower from the factory. Not bad, but it could be better.

For comparison's sake, here are some other factoids:


396 402 427 454
BORE 4.094 4.126 4.250 4.250
STROKE 3.760 3.760 3.760 4.000

396 Big Block Chevy Stroker Build Closed Combustion Chamber Cylinder Heads
Of all the strikes against the 396, the most egregious is its combustion chamber design. Early big-blocks had closed combustion chambers. What does that mean? Compare it with the later, open-chamber heads of a 454 on the left. The 396's intake valve is so buried in the chamber it has very little room to breathe. Air needs room around the valve to flow into the cylinders, and with almost half of the intake valve shrouded like this, it has nowhere to go.
396 Big Block Chevy Stroker Build Closed Combustion Chamber Cylinder Heads
Of all the strikes against the 396, the most egregious is its combustion chamber design. E

A popular big-block build is a 496-that's a 0.060-over 454 (4.310 bore) with a 4.250 crank. Most big-blocks have a 9.800-inch deck height. Heavy-duty truck applications generally have a 10.200-inch deck height.

396, The Bad News
As we walked into his assembly room, Toki told us that of all the big-blocks, a 396 is the least desirable-almost as if he were bracing us for bad news. "With the small bore size, there aren't a lot of pistons available. Same thing goes for the rings. Plus, the heads are terrible." It turns out they are. Let's investigate.

The Toki Solution

  • 396 Big Block Chevy Stroker Build Notch In A 454 Engine Block
    We're just guessing here, but it would seem that Chevrolet had bigger bore diameters in mind when it designed the Gen II big-blocks. With a bore spacing of 4.84 inches and a potential maximum safe bore size of 4.625 inches (theoretically, for the big-block design-most 396 blocks can only be bored out to 4.250 inches), the 396's 4.094-inch bore diameter is laughably small. Notice how the deck of this 454 block had to be notched to clear the intake valve? That notch is even bigger on a 396. This is why larger intake valves don't work in a 396. Just like in the cylinder heads, air does not flow well within the confines of this bore size. Finally, the piston size is just strange. In the '60s, pistons for 396/402s were more readily available, but with the trend toward building bigger-displacement engines, your options for pistons are limited.
    396 Big Block Chevy Stroker Build Notch In A 454 Engine Block
    We're just guessing here, but it would seem that Chevrolet had bigger bore diameters in mi
  • 396 Big Block Chevy Stroker Build Ross Pistons
    Solving the airflow problem is the key to this build. Toki knew he had to go to a bigger bore size to unshroud the valves. How much bigger? A 4.155-inch bore happens to be a 0.030-over 400 small-block piston, and there are a lot more pistons available for that application. Toki ordered a set of forgings from Ross and had the block bored to fit them. Stock 396 rods measure 6.135 inches. These forged RPM I-beams are 0.250 inch long-they measure 6.385 inches. The block was zero-decked to fit the piston to the top of the bore, and with the stock cylinder heads' 98cc combustion chambers, the compression ratio is 9.75:1.
    396 Big Block Chevy Stroker Build Ross Pistons
    Solving the airflow problem is the key to this build. Toki knew he had to go to a bigger b
  • 396 Big Block Chevy Stroker Build Akerly And Childs High Performance Xtreme Rings
    Choosing a readily available piston made finding a ring package that much easier. Toki installed a set of Akerly & Childs High Performance Xtreme rings. The middle ring of the set is a Napier-style ring-it has a ridge running along its outer edge. Properly installed with this ridge facing down toward the crankcase, it acts like a scraper, keeping oil out of the combustion chamber.
    396 Big Block Chevy Stroker Build Akerly And Childs High Performance Xtreme Rings
    Choosing a readily available piston made finding a ring package that much easier. Toki ins
  • 396 Big Block Chevy Stroker Build Forged RPM Crank
    The forged RPM crank is part two of Toki's plan to make power with a 396. This is a 4.250-inch-stroke crank, making it about as big as you can go in a production big-block. Toki's argument is that the long stroke helps the engine breathe better in spite of the undesirable cylinder heads. During the intake phase, having a longer stroke allows the intake charge to build more velocity in the runners. The pistons' longer dwell time at bottom dead center allows the intake charge to maintain that velocity of airflow into the cylinders even as the pistons start to travel back up the cylinders for the compression phase. In short, the long-stroke crank allows for better cylinder filling through these cylinder heads than a stock stroke crank. Yes, it physically moves more air, but the key is how it causes the air to move.
    396 Big Block Chevy Stroker Build Forged RPM Crank
    The forged RPM crank is part two of Toki's plan to make power with a 396. This is a 4.250-
  • 396 Big Block Chevy Stroker Build Partial Fill
    Though it was mainly a precaution, Toki did a partial fill of this engine with Hard Blok before grinding clearance notches in the crankcase for the stroker crank. It's only at the level indicated by the pen, however. This is not a race engine-there is still plenty of room in the water jackets for coolant.
    396 Big Block Chevy Stroker Build Partial Fill
    Though it was mainly a precaution, Toki did a partial fill of this engine with Hard Blok b
  • 396 Big Block Chevy Stroker Build Clearing Area For A Bigger Crank
    Looking at the crankcase, you can see what areas need to be ground to clear the bigger crank.
    396 Big Block Chevy Stroker Build Clearing Area For A Bigger Crank
    Looking at the crankcase, you can see what areas need to be ground to clear the bigger cra
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