Re: Thunderbolt engine

Posted by gone1951 On 2008/9/8 22:52:06

Again looks like Packard did all sorts of things. My engine is a 1951 327ci with an ultramatic behind it. The head which I'm sure is original says 288ST 327AT. I thought that this head was used on both displacement engines and that was why it was marked 288 standard and 327 automatic referring to the transmission. Also everything I have read says that the 327 with a standard transmission had a lower compression head ( 7 to 1 ) and developed 150 hp and when an automatic trans was installed the above higher compression head was used (the one marked 288ST 327AT) which raised the compression ratio to 7.8 to 1 and the horse power to 155.
Looks like the The Thunderbolt name wasn't added until 1953. Too bad, I'd like to have my Thunder. Think the engine looks great with the Thunderbolt on top in red