Editing Oldsmobile engines

==Head combustion chamber volume== Given unlimited octane, and throwing out any differences in heat retention or dissipation, and also discounting any differences in the quench/squish effect, and optimizing the combination of parts for both, the power will be basically the same whether the large chamber or small (64 cc) chamber heads are used on an Olds engine. But once all the factors are combined, there can be- and usually is- a 'winner'. Generally speaking, look for the head that has the most quench surface available. That will give the best detonation resistance and can allow less timing be used which can even help economy. Maximize the head's available quench area by using pistons that are either flat top or a D-shaped dish to provide the most quench action. Avoid the oft-used by the OEM round dished pistons, they do not offer anywhere near as much quench surface as a D-dish can. Build the engine w/a tight (~ 0.040") quench distance. More on quench may be found by searching online as well as the page [http://www.crankshaftcoalition.com/wiki/Quench here] (page still under construction). Whether a dish is needed or if FT pistons can be used will depend on the static compression ratio target vs. the combustion chamber volume. Use FT pistons anytime you can, they are about the best as far as cost, availability, durability, etc. There are times when budget enters into the picture so much that one chamber is favored over another chamber simply because of availability, or valve sizes, or some other feature that is desired that outweighs any consideration of chamber volume. In the case of the Olds 403, many guys have found using Olds 350 heads w/the larger 2.070" x 1.625" Olds valves makes a very decent combo. For more Olds engine build info, there have been several lengthy threads on the Hotrodders forum covering Olds engine builds. One is [http://www.hotrodders.com/forum/recipe-403-olds-69518.html here], there are many more. ==Resources== *[http://www.442.com/oldsfaq/ofe455.htm 455 CID Engine Detail] from 442.com *[http://www.secondchancegarage.com/public/553.cfm 1946-'50 Olds engine specs] from secondchancegarage.com *[[Rebuilding an Oldsmobile engine]] [[Category:Engine]] [[Category:Undeveloped articles]] [[Category:GM]]

| Editing help (opens in new window)