Stroker 360

rustyfloors

I searched and could not find what I was looking for! :(: What all is needed to put a 401 crank in a 360? I've been told,401 crank and rods with 360 pistons! Can I get off the shelf pistons or am I going to have to have a bushing made to fit the 360 pin Dia.? Is the added cubes worth tthe expence or should I just rebuild the 360! I'm looking for 400+ horse power in a street/strip spirit with a mustang t-5!

jeepsr4ever

You would need a bushing for the rods and locks for the pistons...which means custom pistons. I dont think any current AMC 360 pistons have enough meat in the pin area for locks..I may be wrong.

rustyfloors

Think randy could help me with what I need? or are these the pistons I should get and call diamond for a bushing?

http://performanceamstyle.com/Cart/description.php?II=913&sessid=8d2135bd420916733d4c834e2f9fcc6e&divi=amc

or should I call Ross or diamond?

tufcj

The 401 rod uses a 1.001" pin. The 360 uses a .931" pin. You'd either need a custom 360 piston that would accept the 1" pin, or have the 401 rods bushed for the smaller pins, which would have to be floating pins, and require locks, like MC said. Either way, not an "off the shelf" piston or rod. The block would also need to be clearanced for the big ends of the rods. Bob tufcj

AMX69PHATTY

For a 401 Crank in a '70 & up 9.208 Deck Height 360 Block,
off the shelf 360 +.030 4.11 bore cast pistons with a 1.581 Comp. Ht.
will work if '68-69 390 5.790 Connecting Rods are used.
If Rods are re-conditioned they get about .003 shorter and become 5.787 c to c.
If off the shelf forged 360 pistons are 1.581 Comp Ht. they'd also work.
Believe the '68-9 390 rods also use the 1.001 Wrist pins though.
Using nominal dimensons this yields 0.000 deck clearance.
Interesting that this ends up being 390 Cubic Inches

Using a 27cc piston dish volume and 4.25 bore x .045 thick head gaskets,

58cc open chamber heads yields about a 9.38:1 Static CR.
54cc Edelbrock Alum. heads yields about 9.75:1 Ststic CR.
51cc closed chamber heads yields about 10.04:1 Static CR.

If more CR and less Piston to head clearance was desired
then the block deck height could be reduced by milling or
the 401 crank could be offset ground by the desired amount.
Forged pistons with a less than 27cc dish volume would also increase CR.

'70 & up...1/2.......'68-9............Aftermarket...Engine
360.........401.......390....Deck...360 Piston.....Cubic
deck ht....Stroke...Rod....Clear...Comp Ht.......Inches

9.208......1.840....5.787..0.000...1.581..........390

Does this sound right, or is there an overlooked error ???

:-|

rustyfloors

tufcj wrote
The 401 rod uses a 1.001" pin. The 360 uses a .931" pin. You'd either need a custom 360 piston that would accept the 1" pin, or have the 401 rods bushed for the smaller pins, which would have to be floating pins, and require locks, like MC said. Either way, not an "off the shelf" piston or rod. The block would also need to be clearanced for the big ends of the rods.

Bob
tufcj

I'm know about the bushing but, your confusing me on the locks! Are you talking about the spiral lock that holds the pin in?
If so they are included with the above pistons! What about using a stock 401 piston? The service replacement block could be bored for a 360-401(so I've been told) I'm probly wrong!

AMX69PHATTY

With the 360 pistons at 0.00 deck, the Piston to Valve clearance can get pretty tight, especially with cams that have a lot of overlap. Spec I have for stock 401 Pistons is 1.508 Compression Height. Difference in early and late rods, 5.858 - 5.790 = 0.068 Would assume aftermarket 401 Pistons are .020 shorter than stock. So Comp Ht. would be 1.488 + 5.858 + 1.84 = 9.186 9.208 - 9.186 = .022 deck clearance. :-|

rustyfloors

AMX69PHATTY wrote
For a 401 Crank in a '70 & up 9.208 Deck Height 360 Block,
off the shelf 360 +.030 4.11 bore cast pistons with a 1.581 Comp. Ht.
will work if '68-69 390 5.790 Connecting Rods are used.
If Rods are re-conditioned they get about .003 shorter and become 5.787 c to c.
If off the shelf forged 360 pistons are 1.581 Comp Ht. they'd also work.
Believe the '68-9 390 rods also use the 1.001 Wrist pins though.
Using nominal dimensons this yields 0.000 deck clearance.
Interesting that this ends up being 390 Cubic Inches

Using a 27cc piston dish volume and 4.25 bore x .045 thick head gaskets,

58cc open chamber heads yields about a 9.38:1 Static CR.
54cc Edelbrock Alum. heads yields about 9.75:1 Ststic CR.
51cc closed chamber heads yields about 10.04:1 Static CR.

If more CR and less Piston to head clearance was desired
then the block deck height could be reduced by milling or
the 401 crank could be offset ground by the desired amount.
Forged pistons with a less than 27cc dish volume would also increase CR.

'70 & up...1/2.......'68-9............Aftermarket...Engine
360.........401.......390....Deck...360 Piston.....Cubic
deck ht....Stroke...Rod....Clear...Comp Ht.......Inches

9.208......1.840....5.787..0.000...1.581..........390

Does this sound right, or is there an overlooked error ???

:-|

HUMM!! :-|
This sound like the route to go but ,thats putting alot of trust in the machine shop(at my expence)!

What kind of power do you think a rebuilt 360 with the above forged pistons would put out with the performer RPM stuff?
Like I said it will be a street/strip spirit! Desk top dyno anyone???

AMX69PHATTY

I have a 343 block with a 304/360 3.44 stroke crank in it with cast dished top 360 pistons with 0.00 deck clearance. Around 10:1, .513/.529 x 280/295 adv cam, Torker, 850 DP, 1-5/8 Headers, mildly ported dogleg heads 2.02/1.68 StnStl vavles, MSD 6T, TF727 w/3k Stall, 3.73's, 26" MT slicks, street car. Ran 12.6@109, weighs 3250 w/driver, calculates 325 HP at tire. Using 25% drivetrain power loss yields 433 HP at flexplate. It chassis dyno'd 285 HP at tires before ported heads with lower CR. 285 HP and 25% drivetrain loss yields 380 HP at flexplate. That's 1.03 to 1.18 Hp per cubic inch, using 390 C.I. that's 402 to 460 HP. HP is a product of Torque and RPM, so it's all in how the parts work together and where the combination makes peak torque. :wink:

rustyfloors

Based on my lack of knowledge on this subject, I think I'll go with a good set of .030 forged 360 pistons and stick with the stock crank! Anyone think the cast 360 crank would hold up on a 75-150 shot of NOS with the RPM intake,Cam , Carb? That should make up for the power difference! :t: .......................... :-|

AMX69PHATTY

I have no experience with Nitrous Oxide, in an engine anyways :shock:

rustyfloors

AMX69PHATTY wrote
I have no experience with Nitrous Oxide, in an engine anyways :shock:

It's ok in small doses! (Under 150 shot) any more than that you would have to purpose build the engine for NOS(custom cam,race fuel & and so on!)
But all my engine building experience is with small block chevys! I've never built a performance AMC from scratch,done a few overhauls thow!

Finding a machine shop in my area that even knows what an AMC is, is not the easiest task! I believe I read on this board somewere if I get the pistons .005 out of the hole with a .045 gasket it would give me good quench and put me right about were I would need to be on compression ratio with a flat top piston and 58 cc heads! IIRC!....... :-|

fifesjeep

I like ROSS pistons, I haven't had any issues with them plus what-ever you want they'll do and for a good price...
Here is a pic of a 10:1 FF Race piston that's in the 360...

Here are the specs, (Nothing great or let-a-lone an eye opener but good for my intentions).
Bore = 4.110"
C.H. = 1.596"
Pin Dia. = .930"
Lox Type = "DBL" (Four per piston) Ross spiro-lox
Net DOM CC's = -16.000
Dish depth = .140"
Piston weight = 533 grams (I thought about lighter)
The heads have been shaved, I think .014"
The block was shaved, .008"? or maybe it was the other way... It's been so long and I don't feel like digging in my box of receipts...
I forgot the ROL Gasket .045" (I think it was).
And here are my SCAT 343 Forged H-Beam Rods = 5.885"

I'm not 100% sure what the Compression ratio is... I know those piston with a stock 58cc is 10:1...
Anyway, You should call Ross and see what they can do for you...
Wasn't Bulltear offering all sort of pistons etc a little while back?

jeepsr4ever

Those pistons are fine for press fit pins but not for full floating pins :idea:

fifesjeep

jeepsr4ever wrote
Those pistons are fine for press fit pins but not for full floating pins :idea:

Why is that? So seeing that these are full floating in my 360 it's a bad thing?

fifesjeep

Anybody? Reasons why these pistons would be better for a press fit? Sorry didn't mean to hi-jack this thread. I still vote for Ross custom pistons... But then again there are a lot of places that will do just as good or better... for about the same price range.