small block 360 stroked?

[williamgrgn]

i was wondering if i could stroke my 360 buy using a 400 crank and rods or another engine crank and rods?

 

[IQ52]

Nope.

 

[Jonnyuma]

It's why Chevy small block strokers are so much more common than Mopars. You could (theoretically, at least) build the Chevy out of junkyard parts. With a Mopar you have to start with an aftermarket crank and build from there. Even with a cheap-ish Chinese cast crank the parts list alone costs about what a Chevy 383 build costs.
It's bummaroo, but that's life in the Mopar camp.

 

[72Satellite440]

At least now they are more afordable -some for 700... My eagle crank was 1200.00+shipping in 2002...ouch

 

[67 B-body]

Big block and Small block parts do not interchange.....

 

[williamgrgn]

ok cool yeah i didnt know the 400 was a big block im used to chevy and ford i was doing some reading and i found a article about getting 400 hp out of a 318? by boring it .40 over flat top pistons 360 heads ported and polished and intake and carb combo has anyone done this? if so would it just be better to build my 360 up?

 

[rumblefish360]

Re-do your 360.

The Compression needs to be raised for any serious and reasonable performance upgrade. Use either the KB-107, a flat top 2 valve relief Hypereutectic piston or the Speed Pro equal, the http://www.summitracing.com/parts/SLP-H116CP30/.

These slugs will give you close to or a zero deck piston height for a 9.8-1 (At zero deck height) ratio with a 72 cc head (Stock 340/360 head) with a .039 gasket and a great quench area.

I've run the KB's with "J" heads and Edelbrock heads on pump gas (93) without issue.

If you wish to stroke the engine with a 4 inch arm, click this; http://www.summitracing.com/parts/DCC-5007258/
Shop around and see if you can beat the price. I do not remember who the maker is for the MP cranks. I think Eagle, not to sure though.

 

[72Satellite440]

prices have gone down sb/bb alike....Soo your in luck
http://www.eaglerod.com/index.php?option=com_content&task=view&id=33&Itemid=40
$317-380 cast
$793 Forged

 

[williamgrgn]

cool but i had someone just told me to get the high rpms i need i should use a 318 bottom end out of the 70s he claimend that they used 340 castings in the 318s plus the 318 is internaly ballanced instead of extrenal i would want a new egale crank but i dont think i can afford that (unless i have to) right now

 

[Jonnyuma]

If your looking for max HP and torque, skip working the stock heads over. Even a street engine is better served by RHS, Indy, Edelbrock, or even aftermarket Magnum heads. If your building a street/strip car I would suggest not getting too caught up in the crank journal size vs cubic inches (318 vs360) conundrum. If your looking to get 400 or so HP it can be done, reliably, with either block, but the 360, bored .30 over, will give up 1 HP per cubic inch and put you in the ballpark. The 318 is gonna take a little more doin'. If I already had the 360 in my posession, I wouldn't go looking for a 318 to build....unless i was bored and had some money burning a hole in my pocket.
BTW, 360 heads have a larger combustion chamber and will kill the compression of a stock 318. They only flow marginally better, so they're not really worth dickin' around with in my opinion. They create more geometry and compression problems than they're worth. By the time you get em ported, corrected, and otherwise un-F'd, you could have bought a decent set of aftermarket iron heads that flow better and come with new bigger valves, better springs, etc, etc.

 

[Cranky]

Your avatar is of a Challenger. Is this what it's for? Stroker big blocks don't really cost much more then doing a small block plus you end up with more cubes. It's not hard to put a 440 crank into a 400 block ending up with about 450 cubes...and if you want more cubes, you can offset grind the 440 crank for another 30 or so cubes...or just go for the stroker crank and get about 500 cubes and if your pockets are deep 500+ is possible. But you can build a pretty stout stock stroke 360 for less money. What kind of rpm are you looking for? Turning a stock stroke 440 7000+ isn't out of the question. I like high rpm 'compact' engines too but they make lousy street engines and don't product much torque at lower rpm's.

 

[Jonnyuma]

X2. I've seen 4 poppers make 500-800 HP, which is pretty amazing, but they make doodly-squat for torque, comparitvely. Build for torque and the horsepower will come.
I also think that, short of a dedicated drag car, a big-cube small block makes for a better balanced E body. A 451 stroker is the right engine for my own car, but I personally prefer the balance and handling of a small block A or E body.

 

[rumblefish360]

cool but i had someone just told me to get the high rpms i need i should use a 318 bottom end out of the 70s he claimend that they used 340 castings in the 318s plus the 318 is internaly ballanced instead of extrenal i would want a new egale crank but i dont think i can afford that (unless i have to) right now

Well, it's a good thing you mentioned that here otherwise you'd be paying someone money for no reason. RPM's come from valve control (vale springs) properly rated for the cam's lift and the cam's duration dictates RPM band it operates in.

So tell that guy he is fired for starters.

Secondly, the abilty to hold and have the engine live at high RPM's is not what the crank material is about or be it internal or external balance though a forged internal would be best and last longest, at the HP level your seeking it is a moot point.

It is not that the 318 got a 340 crank, it is actually more like the 340 got a 273 crank since there the first "LA" to have a forged crank. Seriously speaking, a forged crank from the factory is just that. Not engine specific. The 360 journal size is different, so THAT becomes engine specific.

Cast crank engines, with nothing special done to them except good machining to stock factory builds will hold in excess of 550 HP reliably.
Spinning a small block past 6500 safely and repeatedly, like for competitive racing or heavy street abuse should have the oil passages modified as per the MoPar engines book.

Stock OE heads can make 400 HP easy. Like sleep walking.

 

[Cranky]

X2. I've seen 4 poppers make 500-800 HP, which is pretty amazing, but they make doodly-squat for torque, comparitvely. Build for torque and the horsepower will come.
I also think that, short of a dedicated drag car, a big-cube small block makes for a better balanced E body. A 451 stroker is the right engine for my own car, but I personally prefer the balance and handling of a small block A or E body.

Yup, the E body cars handle better with less weight up front just like any car will but it's kinda hard to make suggestions until we know what he has and what his intentions are but you can build a big block with aluminum heads, intake, headers and the weight is now pretty close to a small block :headbang:

 

[Hemirunner]

cool but i had someone just told me to get the high rpms i need i should use a 318 bottom end out of the 70s he claimend that they used 340 castings in the 318s plus the 318 is internaly ballanced instead of extrenal i would want a new egale crank but i dont think i can afford that (unless i have to) right now

Buy an Eagle B20509 rotating assembly (after the shop checks out your block) and then upgrade to better heads later. It'll be a mean running 408 after that little upgrade.

 

[williamgrgn]

the pic is just one i found (wish mine looked like that tho) reason why i can really run aftermaket heads is im building this enigne for circle track and the rules wont let me run anything but stock heads so if i just bore out my 360 put a bigger cam different valve springs i should be in the ball park. what about port and polish thought of cc the heads to 78 mabe put a 2.02 intake valve in it would that be a good ideal (btw i cant run roller rockers) would it be a good ideal to ballance the crank and rods? im trying to squeeze this thing like an orange

 

[Hemirunner]

A 408 with stock heads will make somewhere around 300-350hp and a bunch of torque. Those heads are the power killer. On a stock head deal, I wouldn't want any more cubes. Go after cam and compression and do whatever you can to get the heads to work better.

 

[Revhendo]

If you have to run stock heads, can you use magnum heads? I have no real experience with them, but I heard they flow better. (Just what I heard). I worked the heck out of my stock 340 heads and have about 1200 into them. Apparently I should've spent 1300 and got better valve springs....

I put a cast 4 inch arm in my 340 with a .020 overbore and internal balance. Solid lifter cam, zero deck height pistons, single plane intake. Yadda yadda. It runs way harder than any stroker sbc I've ever done.

 

[Hemirunner]

You could run the RHS/Indy iron heads or the engine quest iron heads and those would be much better than the stock heads and none of the chevy guys would know they're not an original iron head.

 

[williamgrgn]

thanks everybody for your help im gonna do some decision making and try to make my old mopar run better than the "everyday" chevy thats out on the track i wanna show them mopar can still whip em