stock 360 pistons?
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stock 360 pistons?
i was wondering if these where the stock pistons for a 360 i was pulling mine apart today and found ones just like these in it FORD 390 FLAT TOP PISTONS .40 OVER SINGLES CAST on eBay!
i was going to buy a set like these but no need to now
i was going to buy a set like these but no need to now
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360s used 390 pistons. The reason is the 390 piston has a lower compression height which causes the piston to top out below the deck, lowering compression. (this in combination with the shorter stroke and longer rod of the 360 vs. the 390) AFAIK, both "Regular Fuel" 2bbl and "Premium Fuel" 4bbl pistons were used in 360s, not 100% sure on that.
You were going to buy a set for what, the 360 rebuild or a 390? Beware used pistons....make sure they are in spec.
You were going to buy a set for what, the 360 rebuild or a 390? Beware used pistons....make sure they are in spec.
Hotshot
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From: Stanley, VA
Both 360 2bbl and 390 4bbl pistons were used in the 360.
Both of these pistons were pulled out of the same engine. This was the first time the engine had ever been torn down so it was like this from the factory.
Both of these pistons were pulled out of the same engine. This was the first time the engine had ever been torn down so it was like this from the factory.
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Correct, same idea. The 410 had a short compression height and 10.5 CR in the 410. Put it .010 down the hole on top of a 390 crank, and you get low, low compression so you can run WOT all day on the lowest price swill you can buy.
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I have had other engines apart (non ford engines) and they always had what we called soap dish pistons in them so i figured thats what these motors ran and was planing on putting in a new set of flat tops like these not knowing that they where the stock pistons so needless to say i was surprised when i took the heads off and found these
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From: Lost
Ford didn't cast new pistons with a big dish to lower the CR, they just dusted off the molds they already had, and dropped the top of the piston ~.010 to give the same effect. Adding an extra .010 between the top of the piston and bottom of the head netted the same result as dishing the piston, so why waste money on new molds?
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From: Spring Hill
Ford didn't cast new pistons with a big dish to lower the CR, they just dusted off the molds they already had, and dropped the top of the piston ~.010 to give the same effect. Adding an extra .010 between the top of the piston and bottom of the head netted the same result as dishing the piston, so why waste money on new molds?
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Ford didn't cast new pistons with a big dish to lower the CR, they just dusted off the molds they already had, and dropped the top of the piston ~.010 to give the same effect. Adding an extra .010 between the top of the piston and bottom of the head netted the same result as dishing the piston, so why waste money on new molds?
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From: Lost
The piston heights did not change. The approximate .010 down the hole in 360s and 390s is due to a whole combination of compression height, rod length and stroke when using the 390 piston in the shorter stroke, longer roded 360, and the short compression height 410 piston in a 390, which has a shorter stroke than the 410.
It appeased the EPA, and made the bean counters happy. New part numbers are MUCH cheaper than casting a whole new set of molds........
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From: Lost
No worries mate. I didn't make it totally clear what I was getting at, so it could have been easily misread.
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ok so on to the next question wether i bore this motor .030 over or keep thew stock bore im putting in new pistons either way my question is can you change the pistons out on the rods at home. i see in some of the pictures here that it looks like its just a clip that holds the pin in place. so is it just a matter of removing the clips and sliding the pin out or is there a little more work involved
Hotshot
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From: Stanley, VA
Yes, these are floating pins, not pressed.
Remove the "C" clip, the pin will push out. The new piston pin will push in. Replace the "C" clip (new ones come with new pistons).
Just be sure you use oil/assy. lube on the pin before installing it.
Remove the "C" clip, the pin will push out. The new piston pin will push in. Replace the "C" clip (new ones come with new pistons).
Just be sure you use oil/assy. lube on the pin before installing it.
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