High Compression VS Low Compression Opinions

my most recent motor...i had these on a shelf for at least 15 years....TRW +30 ...we had no stockers on hand to compare but the dish looks shallow to me? only pic i have...motor buttoned up .Head was milled for a second time as well.
20130713_132436.jpg
 
Just found measurements from the first build 8 years ago and discovered with 9441's it was @7.5:1:eek:
 
Knowing what the cc of the dish is without the compression height information is worthless


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Mike T said:
He said any CH you ask for is available
Click to expand...
Post #62 mentioned the dish looks smaller. He already has the pistons. I'm aware pistons are available with just about any detail that can be thought of.


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Was playing around on one last night. Not as elaborate...Didn't account for top ring location.
 
turbocamino1 said:
my most recent motor...i had these on a shelf for at least 15 years....TRW +30 ...we had no stockers on hand to compare but the dish looks shallow to me? only pic i have...motor buttoned up .Head was milled for a second time as well.View attachment 291864
Click to expand...


I believe that the old TRWs were superseded by the Speed Pros? The Speed Pro has a 25cc dish with a 1.825 compression height. Hopefully someone could confirm this.
 
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For what it's worth, the compression on the previous build was ~ 7.68:1. w/Cal tuning to 610 whp. w/a 71GTQ. The new build is w/9.5:1,that will need to be tested. The old combo was mild mannered until you engaged the turbo. Looking for better response on the low end w/the higher cr. I will adjust my sig to better reflect the builds.
 
SHADOWII said:
Subscribed:
For what it's worth, the compression on the previous build was ~ 7.68:1. w/Cal tuning to 610 whp. w/a 71GTQ. The new build is w/9.5:1,that will need to be tested. The old combo was mild mannered until you engaged the turbo. Looking for better response on the low end w/the higher cr. I will adjust my sig to better reflect the builds.
Click to expand...


Sound close to mine. It's definitely not pig you would think it would be.
 
Mike T said:
At that level of squeeze everything gets very critical......wouldn't reducing the dish another 5cc take it over 11.5:1?
Click to expand...
I didn't calculate that out. Going on stock block and won't be able to pull enough timing without hurting power and throwing a lot of heat in the ex valve with 11.5. I think it's 10.38:1 with a .027" gasket if I feel the need


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Last edited:
Did the math on the .027s too . Looks like your block has been decked and for the pistons to still be .010 in the hole you must have change the CH as well?
 
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