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Old Sep 28, 2009 | 04:14 PM
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I purchased an engine on this site and it turned out that the compression is much lower than I anticipated.

My short block is a 347 with 28cc dish pistons. I am running unmilled 243 castings.

around 8.1:1



Milling the heads would get some of the compression back, but I don't really want to give up my deck thickness.

I have thought about running a thinner gasket, but would that make it easier for me to blow head gaskets running a thin gasket???

I could swap pistons, but that would be a larger expense and I don't really want to do that unless it is the absolute best decision


Or i could just live with the compression I have..........This is going to be a daily driven 93 octane only street car. I am looking for 7-800 at the wheels mustang dyno.



what's the best thing for me to do??
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Old Sep 28, 2009 | 05:23 PM
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At 7-800 hp I dont think you will have much of an issue with warping the heads. I would probably just mill the heads.
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Old Oct 1, 2009 | 03:33 PM
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A local engine builder looked into this for me and we found out that the the dish on the invoice isn't what the pistons are ........the builder said that they are prob a 15-18 cc dish

we may cc the pistons, but he said there is no way that what I have is a 28cc dish. he showed me a set of 26 cc dished pistons and that is not even close to what I have
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Old Oct 1, 2009 | 06:51 PM
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Sounds like the problem is solved then!? Taking 10cc out of those pistons is going to make a significant difference.

With a compression around 8.5:1 (I'm just guessing) you might not have to runn 93 octane afterall... which might make you feel better at the pump!
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Old Oct 2, 2009 | 12:08 PM
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I may try to run 9's on 87..........lol
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Old Oct 6, 2009 | 01:39 PM
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here is some pics of the pistons what do they look like?
Attached Thumbnails Input needed-pistons.jpg   Input needed-piston-1.jpg   Input needed-piston2.jpg   Input needed-piston3.jpg  
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Old Oct 6, 2009 | 07:33 PM
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Diamond -8.6cc dish?

They look just like my pistons - check it out on my site - date Nov 25th, 2006 (a little over half way down)
http://www.buyrcars.com/jag.htm

Originally Posted by bluehawk2
here is some pics of the pistons what do they look like?
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Old Oct 6, 2009 | 07:46 PM
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Here's my 25cc dish wiseco 4.030 piston for comparison.

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Old Oct 6, 2009 | 09:45 PM
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It kinda looks like the 8.66 dish, but I think mine is deeper.
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