AMC 500CI

Elliott

I've been punting some ideas around and could use some input, especially from anyone who has sleeved a 401. I think the 401 rocks, and I think that it builds torque so well for it's size due to the crank design... but I'm no expert. I'd read about sleeving the 401 to ~4.374/500ci and running bb ch*vy rods/pistons and a moldex crank. Seems to me it ought to just pound out the torque unlike a Caddy 500 because of what I think is a better designed crank. I was pretty excited to see the ICH AMC 500 being built and that motivated me even more to research this a lil further for a lower cost option since the iron 401 block is tough enough on it's own virtues (and mega cheaper). What my concern is largely is that if the bore was sleeved to meet the 4.374 in an iron block would that effect the cooling for a road running rig? I know drag racers fill the water jacket and I don't have that option. Whatcha think and what would the Moldex crank cost (would ICH's crank work in my iron block?)?????

jeepsr4ever

I know its not that expensive to build a 427 AMC stroker and to sleeve an overbored 401...hmmmm I have a .060 over 401 sitting here from Hammer (froadin.com) that I am thinking of punching...I should do a buildup on the SOB and see where its dynoed.....but I have alot on my plate right now :-|

Elliott

Dyno is where I was going, really curious to see if this AMC would out crank a big block running the same cubes and minimal other mods, polished heads, port matched stock iron exhaust (non-smog), balanced and cammed for peak torque around 2,400-3,000rpm, performer manifold and the big Truck Avenger carb. I don't know how or what the differences are with the Moldex crank other then stroke, but the stock 401 crank had an advantage in the larger weights and rod journals (for torque) unless I'm mistaken. I think the crank design had a lot to due with how responsive the 401 torque growth is with subtle mods. Do you think I may have something here? Could it be sleeved to 4.374 and still run cool enough? I've never seen one sleeved so I don't know if this is even going to sacrifice any water jacket volume.

jeepsr4ever

I am not sure what we did end up with when we over bored the shinto' out of a 401 but the only advantage other than reground stroke is they will nitride the crank for a small fee..... :-|

Elliott

In their online catalog it looks like Indy Cylinder Head would probably put together a balanced crank kit (with a specified comp ration, I'd run 9.5:1)... leaving me to just get the sleeves. Do you have a price list for ICH? I tried to call and they are closed so I can't even order a catolog.

jeepsr4ever

hmmm I havent done the buyin yet but i will check out my price monday....if i have time..what exactly were all the parts you needed

Elliott

Moldex crank @4.150 Stroke Eagle H beam Rods (6.200x2.100) Forged pistons (Wiesco?) w/.927 free floating pins @ 9.5:1 comp (for the 500CI AMC) Suitable rings for a street/offroad 4x4 Set of sleeves w/4.374" bore for my 401 core Crank/rod bearings Reciprocating parts balanced Harmonic balancer if other then stock 401 is required Thanks :sa:

Elliott

This motor will be using late production AMC heads.

Lifted79CJ7

OK Elliott and MC, you guys have my complete and undivided attention on this one!! :t: This sounds too fun! You guys need to see if building this monster is possible. Keep up the great work! :lo1l: Jack

Elliott

Lifted79CJ7, Thanks Apparently it's been done for drag racing, where they sleeved a block, used a moldex crank, and ran C*vy BB pistons and rods. For my purposes (low rpm) I think the Wiseco forged pistons and Eagle rods are probably way overkill for running 9.5:1. At that comp ratio I could probably use a rod that was a lot cheaper and even cast Ch*vy pistons... flat tops? Don't know if ICH sells those Moldex 401 cranks outright or requires a core, that is sure to make a difference in price. Currently I'm spending all my money building a shop to even work on my projects so it would be awhile before I could venture into this, and I was going to start into my doubler..... However, planning is critical and I want to pool more information so I can get a guy to do some desktop dyno work to map out the cam grind. Plan to start with hyd cam to build the motor and dyno for comparison to what you get for 500CI in the Caddy (and to test the cam grind), then... funds/interest permitting swap in roller cam/lifter/rocker setup and re-dyno. I have a NP435 and Dana 60/C14ff drive train to run all the torque through so that end of things is pretty well set to go. I really have no idea about the sleeving capacity of this block for overboring, so I don't know if the water jacket capacity would even be effected.... possibly not.

Elliott

An alternative 401/500 sleeving may be cheaper, it was partially written up as: Magnaflux, offset grind 401 crank to SBC SJ 2.0" (3.93" stroke), 1/8" filet radius, nitrate, nitride, knife edge, lighten, internal balance $1,050 at Speed-O-Motive; Eagle CRS5850B-3D 5.85" SBC rods; sleeve block to 4.5"(500 cubes), BBC flat tops. This route uses shorter rods 5.85 -vs- 6.20 for less stroke 3.93 -vs- 4.150 while the larger bore compensates 4.5 -vs- 4.374. Is it fair to say the variance in torque would be negligible? I guess I could play with that on a desk top dyno.

Lifted79CJ7

For the desktop dyno, check with Fuzz. I am sure he should be able to help you out with that one. Jack

FSJnovice

I like the sound of this and where it is going. Waiting for the rest of the info to be posted once comp dyno is done. :!: :t:

Elliott

FSJnovice wrote
I like the sound of this and where it is going. Waiting for the rest of the info to be posted once comp dyno is done. :!: :t:

Well, a guy ran this for me on Dyno 2000, he used a stock cylinder though so it's not 500cubes, and open headers.... shoulda' been iron stockers, anywayz.... still impressive at only 452CI (I asked him to run it again at 4.374" cylinder for the 500CI):

***Note that this is on a stock intake and only 600cfm carb.

The Moldex crank used in the Indy "Bracket Master 500"
is 4.15" stroke,
probably safe to say that is probably the largest
stroke we will see for a
stock block (assuming the 401 block can be massaged to
clear those crank
throws). That nets 452.3 cubes with the 4.165 bore,
and 600 ft/lbs of
torque at 2000 RPM!!! (with Ultradyne's smallest
hydraulic (.517/.541 lift &
231/239 duration) AMC cam, stock big-valve dogleg
heads, stock intake,
600CFM 4bbl, small-tube headers w/mufflers, 10.2-1
compression). Not much
HP there, but loads of torque. I also tried adding
fully ported heads,
big-tube headers, big cam, big carb & Torker, the
rev-range is dictated by
the bore/stroke ratio, and 5500 RPM is peaked-out for
this one, no matter
how much cam, exhaust, or intake you throw at it.

Engine Power Torque
RPM (Fly) (Fly)
2000 229 600
2500 266 559
3000 304 532
3500 327 491
4000 320 420
4500 296 345
5000 256 269
5500 207 198

Elliott

OK, here's some Dyno 2000 #s on the 500CI 4.15X4.374 bore on a stock built motor, that means stock, manifold carb, exhaust, ₁₀.2:1 and cammed mild:

This is about the same setup as the previous,
except the bore, and the cam is one notch more
radical.

    RPM    Power  Torque
    2000   246    646
    2500   288    606
    3000   326    571
    3500   346    520
    4000   337    442
    4500   300    350
    5000   257    270
    5500   201    192
    6000   135    118
    6500   59     47

I'm gonna look up a guy to run this on another dyno: http://www.performancetrends.com/EA30.htm

ICH told me the 4.15 crank runs about $2,250, but they could not confirm how that would fit in a stock AMC 401 block as the ICH aluminum blocks are taller.
I'll probably hafta work with my rod length and piston dimensions to get the correct compression height. ICH did say that 4.0 stroke will fit the 401 block.

Camshaft Type: Ultradyne 239_249_1C
Lifter: Hydraulic Lobe Center:108.0
Cam Specs @:0.050-Lift
Int Lift@Valv0e.:525 in Int Duration:239.0
Exh Lift@Valv0e.:546 in Exh Duration:249.0

Elliott

Elliott wrote
An alternative 401/500 sleeving may be cheaper, it was partially written up as:
Magnaflux, offset grind 401 crank to SBC SJ 2.0" (3.93" stroke), 1/8" filet radius, nitrate, nitride, knife edge, lighten, internal balance $1,050 at Speed-O-Motive; Eagle CRS5850B-3D 5.85" SBC rods; sleeve block to 4.5"(500 cubes), BBC flat tops.

This route uses shorter rods 5.85 -vs- 6.20 for less stroke 3.93 -vs- 4.150 while the larger bore compensates 4.5 -vs- 4.374.
Is it fair to say the variance in torque would be negligible?
I guess I could play with that on a desk top dyno.

Thanks for the Dyno work Holeshot! Do you know if this has actually been done... sleeving to 4.5"?
The question came up if the bottom of the cylinder sleeves would have enough support. Below is a pic from MC's cut 360 block which makes it look like at least a significant portion on the bottom of the sleeve would have adequate support. Has anyone sleeved an AMC that can address the feasibility? I do not wish to fill the block, but cool it with a functional water jacket.

Elliott

Looking at some Ross Piston specs the Mopar 400 (with a crank center line to deck height of 9.980 -vs- 9.208 for the AMC 401) the block can be stroked to 500 CI @ 4.375 bore x 4.150 stroke. Don't know if the following could be stuffed into the 401 block as the compression height of the piston is already at 1.120" and to use a shorter rod the piston rings might drop out the bottom of the cylinder sleeve (possibly the pin location could be changed), info below: ROSS Flat top big block Chrysler pistons listed in this section feature special flat top forgings for maximum strength with minimum weight. They will work with open or closed chamber heads. Suitable for nitrous systems of 250 horsepower or less. NOT RECOMMENDED FOR USE WITH FORCED INDUCTION SYSTEMS. Ideal for high performance applications where a flat top piston is desirable. Pins included are aircraft quality and are retained by double spirolox or can be press fitted into rods. Pin location (compression height) used on these pistons will give .017 deck clearance in a new 9.980 (400) block or 10.725 (440) block. Ring grooves are 1/16, 1/16, 3/16. 400 Mopar Flat Top Part # ros99497 Block 400 Bore 4.375 Stroke 4.150 Rod Length 6.768 Dome CC -4 Grams 492 C.H. 1.120 Pin Dia. 0.990 *include oil support rails

Elliott

I ran across a post today that verifies that the ICH crank will interchange with the stock 401 crank: http://www.amxfiles.com/archive/show.cfm?postid=82240&row=3

It also states that the ICH 500 Bracketmaster AMC has a taller deck height of 9.40", which I am figuring is to allow for clearance of the 4.150" throw crank it uses.

Still researching a piston/rod combo that might allow clearance for the 4.150" in the 9.208" deck height factory AMC 401 block.
...
Ok, ran sum numbers and the top end is looking like it might go, using ₆" rods the angle comes in a ₂₀.2* compared to stock 18.3*.

I need some input from anyone out there that has a 401 in tear down mode and I'm looking for the following specs to see how much trouble I'd have fitting the lower end:
If you don't know what I mean about "rod clearance radius" check the pic out.
http://www.imgbay.com/sites/jeepsr4ever///amcr8

I need to figure some rod clearancing specs for the 4.150 stroker and would need the measurements from the top of the cylinder deck to:
1) the very bottom edge of the cylinder
2) the top of the radius for the rod clearancing

Then if you possibly have one together with the cam/crank/rods/pistons in place (not very likely I suppose) I could really use the following measurements:
1) cam lobe to rod clearance, with stock rods (Chevy will be a whole different story, but I'll have a baseline for comparison)
2) cam lift (stock = 0.286)

Thanks for any help you might offer.

Elliott

Elliott wrote
I need to figure some rod clearancing specs for the 4.150 stroker and would need the measurements from the top of the cylinder deck to:
1) the very bottom edge of the cylinder
2) the top of the radius for the rod clearancing

Cylinder Length is 6.023"
Deck to the Rod Relief is 5.688"