AMC V-8 Q

[bovine]

So what sets the AMC V-8's apart? I know externally they are the same. Do they share the same bore size? Heads from a bigger motor give more displacement? 401-360. Just wondering because I read on here about an AMC V-8 stroker kit that'll take a 360-401 and a 401 to something else ALOT bigger. Got me thinking about AMC V-8's.

[nograin]

http://www.ifsja.org/tech/motors/v8specs.html

[j20brett]

im pretty sure there is a catch to stroking the 360...cant remember off the top of my head. And the 401 i dont exactly know about...try searching under stroker 360 maybe

[710 Burner]

No, its the amount of oil that can be lost in a single drive.

[chrisnsarah]

Externally they are all the same (exception is the 327). The difference is in the bore sizes and strokes. The 401 also has a stronger bottom end with forged crank & rods and heavier block webbing.

They all share the same heads (?), same intake, exhaust manifolds, timing cover, adn other external accessories.

[J4GRAND]

They all share the same heads (?),
I believe the 360s and 401s are the same; 304s have smaller valves.

[tgreese]

I believe the 360s and 401s are the same; 304s have smaller valves.
Yes. 304 heads will work on a 360/401, but not vice-versa.

The 250-287-327 was the first generation of AMC V8s, introduced in 1956. It was a big block engine compared to the 304/360/401 we know and love, and would have been capable of 450 cid if AMC had decided to go that route. The 'modern' thin-wall AMC V8 was introduced in 1966 with the 290, 343 in '67 and 390 in '68. 290/343/390 was changed to 304/360/401 in (I think) 1970, about the same time AMC purchased Jeep.

[byson1]

304,360,401-same exact external block and head dimensions. If it bolts onto the outside it will bolt onto any and all of these. (some differences in actaul bolt sizing around 1980 I think)

304,360,401-all use different weight harmonic balancers and flywheels. These V8's are all externally balanced

304,360-same crankshaft (ie same stroke), different size valves, different cylinder bore

360,401 same valve size, different crankshaft. different bore and stroke. The 401 also uses a forged crankshaft

Not sure if I left out anything but that covers most of the engine similarities and differences.

[Serious Johnson]

Cow:

All good and true advice above. I'd add in response to your original query that never will changing heads on an automotive (head/cylinder seperate) motor affect displacement. Compression ratio maybe -- earlier 290-343-390 AMC V-8s used heads with smaller combustion chambers that give higher compression on a given shortblock than do later heads. Thing is, those older heads also flow much less well, so performace is basically a wash at low-mid range, with the newer style heads pumping out a lot more at mid-upper revs.

Just yesterday looked over my neighbor's 11-second street AMX. It's got a .030"-over 390 block, 401 crank & rods, 12:1 forged pop-up pistons, and remarkably stock 360 heads. Back when I was racin' small-block Chebbies, I'da killed for heads with such flow potential. That said, AMC V-8 head castings are some of the sloppiest I've yet seen, and almost anything done to them with a grinder is an improvement.

S.J.