jhelms

iTrader: (2)

What is our stock combustion chamber volume?

And does that number change if you have ported and polished heads?

thanks,

Playdough

Speed, Do stock 6.0L heads bolt right on to a stock 5.7L?

jhelms

iTrader: (2)

So I'm guessing my ported heads should be somewhere near the mid 60cc region?

Speed Demon

iTrader: (14)

John,
I believe Wizkid posted stock chanber cc to be 67.3.

Most ported heads are milled 0.030.
I have read that 60cc is around 11 to 1 CR and
63-64cc is @ 10.6 to 1.

Try doing a search. Someone I'm sure has an excel spreadsheet for calc. chamber volume vs. CR.

If you are planning on going with some boost, you may want to try a set of 6.0L truck heads. They have larger chambers than the stock 5.7 heads and would drop you CR some to allow for more safe boost.

I hope this helps some.

Brandon

Speed Demon

iTrader: (14)

Playdough,
The 6.0L heads are supposed to bolt right on to the LS1 block. That's the general consensus. I sure hope so since I have a set sitting in my garage.

The 6.0L heads have revised ports (better flowing) and larger chambers than the 5.7s.

Do a search for "6.0L" or "truck heads". There is a lot of info on the boards.

John,
I would assume your heads are in the low 60cc range, if they milled them 0.030 in.

horsepower

[quote]Originally posted by Speed Demon:
<strong>John,
I believe Wizkid posted stock chanber cc to be 67.3.

Most ported heads are milled 0.030.
I have read that 60cc is around 11 to 1 CR and
63-64cc is @ 10.6 to 1.

Try doing a search. Someone I'm sure has an excel spreadsheet for calc. chamber volume vs. CR.

If you are planning on going with some boost, you may want to try a set of 6.0L truck heads. They have larger chambers than the stock 5.7 heads and would drop you CR some to allow for more safe boost.

I hope this helps some.

Brandon</strong><hr></blockquote>


To calculate *New* compression ratio from a changed combusion chamber size:

(for STOCK LS1 displacement)

1 - add 10.484 to the cyl head comb. chamber size

2 - add 708.3096 to the number from step 1

3 - divide the number from 2, by the number in 1

example:

60 cc cylinder heads

step 1: 60 + 10.484 = 70.484

step 2: 708.3096 + 70.484 = 778.7936

step 3: 778.7936 / 70.484 = 11.05

(for 382 displacement)
same steps, use 782.4823 instead of 708.3096


Remember, this is all static compression, depending on the cam you choose, your dynamic compression can vary significantly.

-brian


(note, this is based off a 67.4 cc stock chamber only. For another head size (ie, 67.3), just subtract it from 77.8835 to get the addition number in step 1. Example, 77.8835-67.3=10.58)

[ December 06, 2001: Message edited by: horsepower ]</p>

wizkid

iTrader: (3)

Considering everything is stock but the combustion chamber volume.

Combustion Chamber Volume (cc)-- Static Compression Ratio

60 11 :1
61 10.9 :1
62 10.75 :1
63 10.6 :1
64 10.5 :1
65 10.4 :1
66 10.25 :1
67.3 10.1 :1


ERic

wizkid

iTrader: (3)

[quote]Originally posted by horsepower:
<strong>
60 cc cylinder heads

60 + 2.72966 = 62.72966

708.3096 / 62.72966 = 11.29 or 11.29:1 compression ratio

[ December 06, 2001: Message edited by: horsepower ]</strong><hr></blockquote>

I get 11.03:1 for 60cc combustion chambers.

I have a spreadsheet I have written to calculate this easily. I am working on an article and will release the spread sheet with it. I might release the spread sheet a little earlier.

Eric

horsepower

[quote]Originally posted by wizkid:
<strong>

I get 11.03:1 for 60cc combustion chambers.

I have a spreadsheet I have written to calculate this easily. I am working on an article and will release the spread sheet with it. I might release the spread sheet a little earlier.

Eric</strong><hr></blockquote>


yes, i fixed it - goofed my first post <img src="graemlins/gr_cheers.gif" border="0" alt="[cheers]" />

BADZ

iTrader: (5)

Is that with a stock 5.7L head milled .030 to achieve 60cc? <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by wizkid:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by horsepower:
<strong>
60 cc cylinder heads

60 + 2.72966 = 62.72966

708.3096 / 62.72966 = 11.29 or 11.29:1 compression ratio

[ December 06, 2001: Message edited by: horsepower ]</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I get 11.03:1 for 60cc combustion chambers.

I have a spreadsheet I have written to calculate this easily. I am working on an article and will release the spread sheet with it. I might release the spread sheet a little earlier.

Eric</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">

jhelms

iTrader: (2)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by jhelms:
<strong>WAY BACK IN DECEMBER 2001</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Wow, this post came back from the grave! <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />