Re: Thunderbolt engine

Posted by David Baird On 2008/9/9 17:49:32

Bob1951;
I believe the compression for your 51 would be the same as the 48-50, which was 7:1. With a 288 head it would have increased to 7.5:1.

The head that was on my 1948 Custom is for a 327, it says "Packard Thunderbolt" and was cast on 3-4-54. The head on my other 1948 Custom engine says "Packard" and was cast on 1-28-48. So, it would seem that somewhere between 1948 and 1954 Packard adopted the name Thunderbolt. If we keep checking casting dates we should be able narrow this down even more.