351c 2v aussie heads?
Thread Starter
|
Elder User
Joined: Jan 2004
Posts: 867
Likes: 0
From: Eastern Pa
351c 2v aussie heads?
While surfing some links I found one which showed the aussies had a 351c 2v head in open chamber design with 75cc chambers. Are these ever avalilable anywhere? I always just see the closed chamber ones. A set of these would put me right in the cr range I would like to be in.
Hotshot
Joined: Dec 2003
Posts: 18,423
Likes: 9
From: iowa
The open chamber 351c heads are just any 2v 351c head that you can find in any junk yard the closed chamber are an australian head that was used on the 302c, the ports are the same as the regular 2v heads but closed chamber and they are approx 58cc chambers.
Thread Starter
|
Elder User
Joined: Jan 2004
Posts: 867
Likes: 0
From: Eastern Pa
That's what I thought but when I came upon this http://phystutor.tripod.com/stang/en...cleveland.html
there is a chart showing an Aussie head on mid 70 to early 80's with a chamber 4-5cc smaller than what we are accustomed to seeing.
there is a chart showing an Aussie head on mid 70 to early 80's with a chamber 4-5cc smaller than what we are accustomed to seeing.
Posting Legend
Joined: Sep 2001
Posts: 30,255
Likes: 37
You can make small CC adjustments milling the head and deck. Every 0.010" == 2cc with open chamber heads or the block. Remember that when an engine is rebuilt approx 0.010" will be taken off the heads and deck during the normal re-surfacing/cleanup operations. That in itself will be ~4cc. When the engine has been taken apart you will be able to measure the deck height. There are manufacturing variations and if the engine or heads have had work done before they may have already been resurfaced. You need to have your heads cc'd to check for uneven chambers etc. so you know where you are starting from. Your heads can be trued to even out the chambers.
Thread Starter
|
Elder User
Joined: Jan 2004
Posts: 867
Likes: 0
From: Eastern Pa
Well here's is my dillema. I have the Crane 272-h which recommends a cr of 8.5:1 to 10.5:1. When I worked on my stock 400 head I unshrouded the exhaust valve and before I knew it I had gotten to 82.3cc. With the Badger pistons and the deck apparently never being touched, ( I'm .06-.07 in the hole) I end up with 8.7:1. The heads have already been cut about .023. I'm right at the bottom of the recommended cr range for the cam and would have liked to have been at 9.5-9.8 or so. It runs great from 2000 to past 5000, but I would have liked the extra point in cr. So the only way out I see is the new pistons TMeyer has which would require a tear down, or a head that would get me what I want.
Hotshot
Joined: Dec 2003
Posts: 18,423
Likes: 9
From: iowa
did you really mean .06-.07 or did you mean .006-.007 if you meant 60-70 thousands, and a tear down is a major possiblility try decking the block by .040, and get that deck to piston hieght down to .020, that will greatly increase your compresion, infact acordding to my calc it would end up at 9.5, I realize it is alot of work but that would probably be the cheapest, and easiest.
