Hot Rod Forum banner

SBC Heads and Compression Ratios

823 views 4 replies 3 participants last post by  techinspector1 
#1 ·
Hi guys,

Does anyone what the specs of the 305 081 and 087 heads are? I need to work out compression ratios as I may have cocked up when ordering some pistons.

Cheers
 
#3 ·
Stop and ask yourself how many owners these heads have had since new and what modifications have been made to them before you got them. The very least that you should do is to cc the chambers to be sure what you're working with. After that, check for being angle milled. If they've been angle milled, the chances of sealing up the manifold are pretty slim, without doing some machine work to the manifold.

It just amazes me to see you fellows, one right behind the other, grabbing a set of cylinder heads from God-knows-where and bolting them on your motor without knowing anything about them. NUCKING FUTS.
 
#4 ·
I wouldn't just slap a set of heads on, they're the ones off my engine but they're off being cleaned and I needed to know what the specs were to make sure the CR is right with the new pistons, I figured they had to be either of those two but some places don't have all the info.
 
#5 ·
That's my point. It is not incumbent on someone else to have the information on your heads. They're your heads, so take the common sense initiative and measure them yourself. If you have not owned the heads since they were cast at the foundry, then you have no idea what the specs are on them and neither does anyone else.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top