Are the 4.6's and 5.4's big blocks or small blocks?
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blueovalguy
Active Member
Neither, it's a mod motor.
small blocks were 221, 260, 289, 302 (5.0) & 351W
big blocks were 352, 390, 406, 427, and 428
351C, 429, and 460 were 385 blocks.
small blocks were 221, 260, 289, 302 (5.0) & 351W
big blocks were 352, 390, 406, 427, and 428
351C, 429, and 460 were 385 blocks.
i had always understood that a small bock is anything under 400 CID and a big block was anything over 400CID. now a 351 stroked to 427 is still a small block because the 289/302/351 windsor blocks are comsidered a small block the 4.6 and 5.4 are small blocks, but are of a different architecture and are therefore called the "mod motors." kind of like how a 350 is different from a LS1 becuase the parts arent interchangable. if i remember right there was both a small block chevy 400 and a big block chevy 400, theu just used different blocks.
according to ford, big blocks are anything over 390 cubic inches. their 400ci block was considered a big block...this history on ford book I have might be wrong, but its made by ford, so i dunno. 281 = smaller than 289 and the 289 was considered a super small block in the 60s. we have OHC engines tho so we "appear" bigger 
Monkie
Active Member
"Are the 4.6's and 5.4's big blocks or small blocks?" 
They are small blocks. It just strikes me at being hella funny that you asked that. But I remember a time when I couldn't have told you either. 
They are small blocks. It just strikes me at being hella funny that you asked that. But I remember a time when I couldn't have told you either.
Monkie
Active Member
70stangcoupe
Founding Member
All the size is because of the heads.
The blocks are relatively small.
Ford doesn't differentiate between big block and small block anymore.
The blocks are relatively small.
Ford doesn't differentiate between big block and small block anymore.
03trubluGT
New Member
KingMidas said:
The 4.6 is 281ci and the 5.4 is 330 ci. They are the same block, except the 5.4 has a taller deck height (the cylinders are taller), therefore making the intakes made for the 4.6 unusable unless you use a spacer.
The v10 is just a 5.4 block with 2 more cylinders.
Matt
Monkie
Active Member
I still think its dumb as hell that Ford has a 4.6L V8. 
It should ATLEAST be a 5.4L V8 since it has OHCs. 
It should ATLEAST be a 5.4L V8 since it has OHCs. 
KingMidas said:
The FE engines are considered big blocks 332, 352, 390, 406, 410, 427, 428
The 385 family (429 & 460) are also big blocks.
What makes a block a big block is the cylinder bore (or bore spacing) In general anything that is capable of more than a 4" bore is considered a big block. The 427 has the biggest bore of the FE family @ 4.23" with a 4.63" bore spacing (same for all FE engines). The 385 family stock bore is 4.36", with a 3.9" bore spacing.
The 351C is part of the Cleveland family (351C, 351M & 400). With a factory bore of 4.00", bore spacing of 4.38" (same as the 289-302) it's considered a small block, although some call it a "Mid-Block" because of the long stroke 400CID version.
Since the 4.6 & 5.4 Modular engines have a bore of only 3.55", they would clearly be considered small blocks. As someone else said, the 4.6 block is tiny, it's just that the OHC heads are HUGE.
Slithering_Joe
Founding Member
Semi-Hemi BOSS 429
forpit2000gt
Founding Member
Thanks for the info, I believe I was told this years ago. 289 and 302 block same, different stroke.?? same with 429 and 460, same block , you get the addition displacement from bore and stroke. I never thought about the mod motor, I thought it was all by itself, a mod motor. Technically, it may be the end results of Mazda being involved with Ford, or at least someone has paid attention to the imports at some time or another..( is that blasphemy???)351CJ said:
forpit2000gt
Founding Member
when th mod motor came out I thought it meant Modular, the same 1 or 2 blocks would be used in all v8 cars, then a modular concept of different intakes would be installed for the application, truck ,passenger car, sports car... etc..
Cali03Boss said:according to ford, big blocks are anything over 390 cubic inches. their 400ci block was considered a big block...this history on ford book I have might be wrong, but its made by ford, so i dunno. 281 = smaller than 289 and the 289 was considered a super small block in the 60s. we have OHC engines tho so we "appear" bigger
Actually, it goes like this:
Small block Fords are:
221 CI, 260 CI, 289 CI (Reg and high po w/mechanical lifters), 302 (5.0L), Boss 302, 351W (5.8L), Ford Classifiies the 351C as a small block with big block attitude is the first of the 335 series family (same heads as boss 302), 351M and 400M (a modified cleveland block with a taller deck height .500), the gas efficient (yeah right) 255CI introduced in 78-79.
FE introduced in 1958 were:
332/353/361CI
in 1961 came the 360/390CI, the 410 (was a mercury only motor)
the the 360 is the same as the 390 in bore and block dimensions (just the 360 has the 352 crank)
in 1962 came the 406/427 Single cam motors. The significantly different cammer 427 SOHC was banned from NASCAR because of unfair advantages.
1966 uhsered in the 428 a low reving high torque motor originally designed for station wagon and family car use such as galaxie.
Also we have the FT (Ford truck) series motors 330, 361, 391.
Then we have the 385 series big blocks 429CI, and the 460CI also available were the Boss 429 Used in approximately 500 Mustangs in 1969.
Hope this clears some thing up for you guys.
MEL (mercury-edsel-Lincoln) series big blocks are:
383CI, 430Ci, and 462CI.
Modular motors are physically 'wider' due to the 90 degree angle formed by the right and left sides of the block in relation to the crankshaft. In other words, the 'V' of the V8 on a modular motor is a 90 degree angle, whereas the angle of the 'V' on the older Ford small blocks (260, 289, 302 and 351W) is more along the lines of a 60-70 degree angle. Therefore, even though the displacement on the 4.6 is smaller, the 90 degree angle makes it wider than the older Ford small blocks that sported larger displacements. Also, stock DOHC and SOHC heads are wider than the stock heads that came on old Ford small blocks.
Regards,
GTGunner
Regards,
GTGunner
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