400 2 barrel heads
Posting Guru
Joined: Aug 2000
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From: PacNW
Check out the thread on the 400 Tim Meyer is building:
https://www.ford-trucks.com/forums/s...d.php?t=329627
It's a 400 with a set of his semi custom flat tops with Aussie heads. He's dynoing it with 87 octane pump gas.
Remember in order to accurately calculate the compression ratio you have to take into account the total volume above the piston which includes the area inside the cylinder that the piston doesn't occupy. In other words the only way to truly get a decent fix on C.R. you have to install a piston, bring it to TDC, measure the amount of liquid it takes to fill the space and add the combustion chamber size and compressed head gasket thickness.
https://www.ford-trucks.com/forums/s...d.php?t=329627
It's a 400 with a set of his semi custom flat tops with Aussie heads. He's dynoing it with 87 octane pump gas.
Remember in order to accurately calculate the compression ratio you have to take into account the total volume above the piston which includes the area inside the cylinder that the piston doesn't occupy. In other words the only way to truly get a decent fix on C.R. you have to install a piston, bring it to TDC, measure the amount of liquid it takes to fill the space and add the combustion chamber size and compressed head gasket thickness.
Tuned
Joined: Mar 2004
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Correct me if I am wrong, but I thought that these Badger flattops that Tim Meyer is using on his 400 came all the way to the top of the deck. I bought these flattops for my 400 with this impression. Maybe I am wrong, and I don't regret what I purchased because they have worked out beautifully, but I think I remember him telling me that they came all the way to the top of the deck. If not, I know they come pretty close....when I was stabbing my dizzy, I took the #1 plug out at 0TDC and the pistong was right there. Very little room from the head to the flattop....
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From: PacNW
I don't know which pistons you bought. If they're the stock Badger flat tops then they don't come up to zero deck without some extensive milling of the block. If you bought the modified version that Tim worked with Badger to produce then they will come up to zero deck.
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From: in a house
with the standard badger flat top 40010F it will sit at about .060" down in the block. but you should still CC the block to get an accurate total compression volume. the space for valve reliefs and area around the piston above the rings can't be calculated otherwise.
and like stated before don't forget the gasket. with a 4.100 x .041" head gasket you will have to add another 8.7cc. so if your planning on stuff like milling heads or block or installing aftermarket pistons you should really do it by the book. thats why you hear people say they don't have any detonation problems with a given compression ratio when in fact it was much lower than they thought.
and like stated before don't forget the gasket. with a 4.100 x .041" head gasket you will have to add another 8.7cc. so if your planning on stuff like milling heads or block or installing aftermarket pistons you should really do it by the book. thats why you hear people say they don't have any detonation problems with a given compression ratio when in fact it was much lower than they thought.
Tuned
Joined: Mar 2004
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When the pistons were put in, the heads were off, and that is when they were measured.
These are the standard badger flattops. They must not come all the way up, but they do come up farther than the stock 351M pistons. The heads were milled a little, but not extensively. So there is probably about .060 clearance in there. Couldn't remember for sure, but now I know.
These are the standard badger flattops. They must not come all the way up, but they do come up farther than the stock 351M pistons. The heads were milled a little, but not extensively. So there is probably about .060 clearance in there. Couldn't remember for sure, but now I know.
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tastyklair
FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428)
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Jun 29, 2004 11:18 PM
