How to Rebuild Horsepower in a Pontiac 326 Engineby Don Kress
Rebuilding horsepower in any early V8 engine is a tricky job to undertake. There are two paths in which you can take: do you rebuild the engine to original specifications, or rebuild it with current parts which will far exceed the performance potential of the original engine? Both can be prohibitively expensive tasks to undertake, but for a true restoration or numbers-matching rebuild, there really is no other way to go to rebuild your Tempest, Le Mans or early GTO.
Unbolt the exhaust headers from the exhaust system of the car using the socket set, then drain the [engine coolant](https://itstillruns.com/what-is-engine-coolant-13579658.html) by pulling the lower radiator hose out of the radiator. When the coolant is drained, disconnect the throttle linkage and fuel line from the carburetor, remove the upper radiator hose, then unbolt the engine block from the engine mounts located just underneath the headers. Unbolt the engine from the transmission, then hook the engine block up to an engine hoist.
Remove the 326 engine from the car in which it is housed using an engine hoist. Do not remove the transmission of the car unless you intend to rebuild it as well. Align the rear of the engine with the mounting holes for the engine stand, then bolt the engine onto the stand securely using a ratchet and the bolts which mounted the engine to the transmission.
Disassemble the 326 engine from the top to the bottom, leaving only the engine block mounted to the stand. Lay out the parts as you remove them on a clean work surface so that the first part you remove is at the far left of the work space, and the last part removed is at the far right. This will simplify replacement and installation of the engine rebuild kit.
Clean the mounting surfaces of the parts which will be reused. Scrape away all old gasket material with a gasket scraper, leaving a clean surface on which to mount the replacement parts.
Rebuild the engine by installing the new components and gaskets from the bottom to the top, replacing the old gaskets with new as well as worn parts such as the crankshaft, pistons, rods and camshaft with new or refurbished components. Rebuild or replace the cylinder heads using new rocker arms and springs, as older springs lose tension and thus, reduce the power of the engine.
Top the engine with a re-manufactured carburetor, then install the engine back into the car's engine compartment.
- Rebuilding the engine of the car simply replaces the lost compression. For increased horsepower, the installation of a "stroker" crankshaft can increase the displacement of the engine to achieve the power levels desired, but must be matched with an appropriate intake manifold, carburetor and camshaft. If you are uncertain about the engine rebuild, it is generally best to leave the job to professionals.
Items you will need
- 326 engine rebuild kit
- 3/8 inch socket set
- Engine hoist
- Engine stand
- Gasket scraper
- Re-manufactured carburetor
- "Pontiac GTO Restoration Guide, 1964-1972"; Paul Zazarine; 1995
- "How to Build Max Performance Pontiac V8s"; Jim Hand; 2004
- "Engine Builder's Handbook"; Tom Monroe; 1996
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