FLAT HEAD PISTONS
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FLAT HEAD PISTONS
I have a 1999 f250 superduty and am going to rebuild the engine with some upgrades need some input on if 2005 pistons will work in my 1999. No info on the compression ratio to compare.
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Joined: Jun 2008
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From: Wayyy NoCal, USA
I can't give a definitive answer, but will share what I know.
I successfully installed a complete 2006 short block under a set of 2V PI heads with no modifications or interferences. I am pretty sure I ended up with a bit higher compression. I now have to run premium fuel when pulling heavy on warm days. But boy, does it run STRONG.
I compared the tops of the pistons on my '99 short block and the '06 short block. They are very similar, but NOT identical. The dished area and depth WAS slightly different, and I recall my calculations showed the 3V piston did have less volume in the dish. The distance from the block deck to the outer edge of the piston (the tallest area) was within a couple thousandths.
What I don't know for sure is if the connecting rods remained the exact same length between '99 and '06, and if likewise, the distance from wrist pin bearing to piston crown remained exactly the same.
If they did, the '05 piston should not result in interferances under a non-PI 2V head. But I do not know what the compression ration will end up being. I have heard the combustion chamber volumes did vary a bit between the non-PI 2V, the PI 2V, and the 3V.
I successfully installed a complete 2006 short block under a set of 2V PI heads with no modifications or interferences. I am pretty sure I ended up with a bit higher compression. I now have to run premium fuel when pulling heavy on warm days. But boy, does it run STRONG.
I compared the tops of the pistons on my '99 short block and the '06 short block. They are very similar, but NOT identical. The dished area and depth WAS slightly different, and I recall my calculations showed the 3V piston did have less volume in the dish. The distance from the block deck to the outer edge of the piston (the tallest area) was within a couple thousandths.
What I don't know for sure is if the connecting rods remained the exact same length between '99 and '06, and if likewise, the distance from wrist pin bearing to piston crown remained exactly the same.
If they did, the '05 piston should not result in interferances under a non-PI 2V head. But I do not know what the compression ration will end up being. I have heard the combustion chamber volumes did vary a bit between the non-PI 2V, the PI 2V, and the 3V.
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Joined: Sep 2010
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good info
just curious, why not upgrade to 3v heads?
the best way might be to compare pistons and see.
the wrist pin height should not have changed, or it would have gotten higher, resulting in longer rods for more dwell and better breathing.
since you say that the deck height is the same, and the piston-deck clearance is close to the same, then i would have to assume that the pistons are about the same.
next question:
why?
a piston with 3 valve reliefs is worse for performance than a piston with 2 valve reliefs. the difference is more than made up for with 3v heads, but if you keep 2v heads, you are only losing.
just curious, why not upgrade to 3v heads?
the best way might be to compare pistons and see.
the wrist pin height should not have changed, or it would have gotten higher, resulting in longer rods for more dwell and better breathing.
since you say that the deck height is the same, and the piston-deck clearance is close to the same, then i would have to assume that the pistons are about the same.
next question:
why?
a piston with 3 valve reliefs is worse for performance than a piston with 2 valve reliefs. the difference is more than made up for with 3v heads, but if you keep 2v heads, you are only losing.
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