If it's not too late to jump in here, to achieve a 9.75:1 ratio, I had to
mill the head 0.115" on my '78 Spit. I am running flat top pistons,
decked block, ported and modified head, CC'd (37.2cc), 270 cam, etc. Car
runs on premium with about 12 deg advance and little problem with pinging
unless the weather is pretty hot. Carbs are HIF4s. Hope that helps a
bit.
Dale O
'78 Spit
'76 TR6
>
>I am considering having the head on my Spitfire milled down to give me
a
>little more compression. It is a stock 80 head so it is currently
about
>7.5 to
>1. I am thinking of taking it to about 9 to 1. Can anyone tell me how
>much
>I would need to take off to get it to that compression?
>
>If I do have it milled down, do I need to get shorter pushrods or is
that
>within normal adjustment.
=== This list supported in part by The Vintage Triumph Register
=== http://www.vtr.org
|