390 Horsepower/Torque Output
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Originally Posted by FalconStng
I have a 1973 Ford F100 with a stock 390/C6. How can I find the factory engine specifications? How much improvement can I expect by rebuilding/boring .030 over/4 barrel intake, carb/ a bit of a cam/ headers?
-Scouder
#4
I disagree also.
Just finished my first FE 390 in a 74 F250 and the combination of bumping the cam up a couple steps (Meling dual pattern, 214/224 maybe??), headers (Hooker), Holley Street Avenger carb, and an overall rebuild kicked things up a LOT. I also spend a couple of weeks porting (myself, with bits and pieces picked up off of the web and various forums, D2TE heads if I remember right). Fun rebuild, work great. HP a bit higher in the range than the C6 likes to shift for. (FYI, I am up in the Denver area, so I may be a bit higher altitude than you. Makes some difference in timing, cam timing, etc.).
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#8
Originally Posted by FalconStng
Unfortunately I've already purchased the pistons....stock top 4.080" (.030 over). How about a thinner head gasket to up the compression....or shave the heads???
Thanks for the info.
Thanks for the info.
Welcome aboard! --Mike
#9
I don't know. I ordered the FE 390 rebuild kit from Summit Racing....pt #FEM-MKP601M-300. that includes .030 over pistons for a ford 390. I don't have them yet but they are to be delivered today. I had planned to take them to the machine shop today so they can check and do the boring. Maybe I should call summit and see about shipping just the pistons back and replacing them...I'm anxious to get this thing back together. If I get the 360 pistons what does that change the compression ratio to?
#12
Summit says the pistons I've ordered are stock replacement pistons...That 360 pistons are ..116" higher in the cylinder and will stick up past the deck....which doesn't make sense to me because I thought that the 360 and 390 blocks are identical. Also they said if I did change to 360 pistons that I wouldn't be able to run on pump gas because compression ratio would be 10.6 to 1. Help!!!
#13
They're full of so much bovine excrement...
The 360 pistons in a 390 will NOT stick above the deck, you'll have .012" deck clearance (I measured mine when I built my 390). They're just the right deck height. Plus, they will NOT give you 10.6:1 compression. If you figure 10cc valve reliefs, 72cc chambers, and .012" deck clearance, in a .030" overbored 390, with a .043" thick fel-pro permatorque head gasket, you'll get 9.511:1 compression. That's not too bad IMO.
The compression height of truck 390 pistons is 1.680"
The compression height of 360 pistons is 1.776"
The difference is .096"
They've got their numbers wrong.
The 360 pistons in a 390 will NOT stick above the deck, you'll have .012" deck clearance (I measured mine when I built my 390). They're just the right deck height. Plus, they will NOT give you 10.6:1 compression. If you figure 10cc valve reliefs, 72cc chambers, and .012" deck clearance, in a .030" overbored 390, with a .043" thick fel-pro permatorque head gasket, you'll get 9.511:1 compression. That's not too bad IMO.
The compression height of truck 390 pistons is 1.680"
The compression height of 360 pistons is 1.776"
The difference is .096"
They've got their numbers wrong.
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Originally Posted by rusty70f100
They're full of so much bovine excrement...
The 360 pistons in a 390 will NOT stick above the deck, you'll have .012" deck clearance (I measured mine when I built my 390). They're just the right deck height. Plus, they will NOT give you 10.6:1 compression. If you figure 10cc valve reliefs, 72cc chambers, and .012" deck clearance, in a .030" overbored 390, with a .043" thick fel-pro permatorque head gasket, you'll get 9.511:1 compression. That's not too bad IMO.
The compression height of truck 390 pistons is 1.680"
The compression height of 360 pistons is 1.776"
The difference is .096"
They've got their numbers wrong.
The 360 pistons in a 390 will NOT stick above the deck, you'll have .012" deck clearance (I measured mine when I built my 390). They're just the right deck height. Plus, they will NOT give you 10.6:1 compression. If you figure 10cc valve reliefs, 72cc chambers, and .012" deck clearance, in a .030" overbored 390, with a .043" thick fel-pro permatorque head gasket, you'll get 9.511:1 compression. That's not too bad IMO.
The compression height of truck 390 pistons is 1.680"
The compression height of 360 pistons is 1.776"
The difference is .096"
They've got their numbers wrong.
--Mike