I know a stock b16 head vs a stock b18c head has a different volume and that by simply changing heads you can increase compression...

I'm really interested in how much you can open up the combustion chamber of a head to increase the volume, but at the same time how much compression do you lose?

And vice versa, a properly rewelded and reshaped (and of course ported + polished) head will be able to effectively raise compression as well... correct?

Since we are dealing with finite amounts of mass - what is the point of diminshing returns... I'm assuming you'll hit a coolant passage if you overport.

Also, how much can you raise or lower the static compression ratio by reshaping the head?

How much flow can you gain or lose by reshaping the head?

Let's talk about different head packages/ stages.

Let's not limit ourselves to stock bore - but discuss overbore (84-86mm) head's as well.....


Modified by Black R at 10:36 AM 2/4/2005


Modified by Black R at 10:38 AM 2/4/2005

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Black R &raquo;</TD></TR><TR><TD CLASS="quote">
This will also affect displacement, correct?
</TD></TR></TABLE>
Combustion chamber volume does not affect displacement. Displacement is a function of bore and stroke.

 

The ONLY things that change the displacement are the bore and stroke. You cannot do anything to the head to change an engine's displacement.

Adding or removing material, or changeing the volume of the head will affect compression.

Pirate

 

Fixed post.

Thanks guys!

On with the discussion.....