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intensedak39
*GenIII*
11/17/2005
15:34:22
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 Subject: RE: 360 crank in a 318?
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"The small block Hemi heads chamber size was added to acheve 426cid BTW."
the chamber size does not effect the cubic inches of the motor
... btw
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gen1dak
Dodge Dakota
JOIN HERE
11/19/2005
04:06:27
| RE: 360 crank in a 318?
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Also, due to casting variations from the assembly line, not all the smallblocks can take .090" over (some maybe just .080", which is why the sonic testing is vital for serious over-bore.
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2003 4.7
Dodge Dakota
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11/21/2005
00:31:15
| RE: 360 crank in a 318?
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Hey Intense, yea I know chamber size does not affect cid. But those heads have rather large chambers, and we just rounded them into the equation.
gen-1 Thats the only block I've seen with my own eyes that will handle .090. I've heard of a few more though. I think the first two years of production on the 360 had a slightly thicker casting cause this ones a first year number.
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gen1dak
Dodge Dakota
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11/21/2005
12:18:13
| RE: 360 crank in a 318?
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Yeah the first couple years were better. Hensley Motorsports offers a 402 "Sucker Punch" 318 where they do that .090" overbore . Same deal. Sonic testing reveals where they can be used or not. They prefer the earlier blocks because they had higher nickel content.
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intensedak39
*GenIII*
11/21/2005
14:52:45
| RE: 360 crank in a 318?
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what did you round into the equation???
i'm lost??
the size of the motor is determined by the bore size and the amount of stroke... then multiplied by the amount of cylinders. The only thing the chamber size is going to have an effect on is your compression ratio.
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2003 4.7
Dodge Dakota
JOIN HERE
11/22/2005
01:07:28
| RE: 360 crank in a 318?
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Intense, it's been a couple years since it was added up. 1cc = Xci. Those heads have large chambers so we figured the heads CID. I know it's not normal to do that though. I can't remember if we did it that way to make the nesassary CID or, if it was so the block would'nt be at maximum overbore. But, yes, normally bore x stroke is what I use.
As far as compression ratio, you'd need a serious dome piston in those heads as it looked to me.
your pet engine is pretty cool too. I could only amagine a 400 B in a Dakota.
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intensedak39
*GenIII*
11/22/2005
03:27:47
| RE: 360 crank in a 318?
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here's how you figure out the size of a motor:
Displacement = Stroke x pie x (Bore / 2)2 x [# of cylinders]
there is no measurement of the combustion chamber used in the process. Would a motor be bigger if it used a .060" head gasket compared to a .020?
lol... just go with it i guess
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2003 4.7
Dodge Dakota
JOIN HERE
11/22/2005
15:59:23
| RE: 360 crank in a 318?
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I haven't had to figure displacement on paper since school. I just use an engine calculator now. All we did is take the figure that the calculator spat out, and then I figured the " displacement" of the heads and then added it in. That is the only time I've ever done that, and thought it was albeit a little strange, kind of cool. If you want technicality, then a thicker head gasket does increase the volume of a cylinder. But not what I call the "swept volume" the part of the cylinder the piston occupies in it's travel. I've modified a couple of engines in that way to lower static compression. Look at a turbo calculator, it figures the displacment of the block, the volume of the head, and the thickness of the gasket. You can really affect the numbers by just changing the thickness of the gasket. All in all they all add up to more cylinder volume, or cubic inches, however you want to say it.
But there is no substitute for cubic or pubic inches, no matter how you look at it!
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intensedak39
*GenIII*
11/22/2005
18:52:03
| RE: 360 crank in a 318?
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well... a mopar 2.2 is still a mopar 2.2 with a turbo on it or not. The turbo calculators are usually there to calculate volumetic effiency.
my 400ci motor is still a 400ci motor even though i had heads that were 95cc and now that are 78cc.
the motor is measured by the bore/stroke, because that's the amount of air the motor can pull in. From the area where the piston is at TDC to the area where it is at BDC, is the amount of air it can pump in.
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2003 4.7
Dodge Dakota
JOIN HERE
11/23/2005
01:29:51
| RE: 360 crank in a 318?
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I see your point. I know that cubic inces are traditionally measured only on the block. All I'm saying is that I counted the total volume of space. It really does'nt matter how you look at it space is space. In the block, head, or gasket. Your 400 B is still a 400. But if you changed from a smoger 98CC head to a more efficent 78CC then you reduced the total amount of volume of the cylinder on a mathamatic scale. That reduction of air is virtually nill however. The reduction of space that the total volume of air goes into is way more noticeable. (higher compression) Mabe thats where we're disagreeing. Your saying that the head volume does'nt affect cubic inches. Traditionally it does'nt no. All I'm saying is that anything you change in a cylinder will affect it's total volume. Say for instance, that if you have a cylinder that is flat on both ends, it's going to have a set volume. Now lets add a dome to one end, you have increased the total volume of the cylinder. I just tend to look at things from a purely mathamatical view. I'm not trying to argue that it's how to , or, how not to measure cubic inches in an engine. Because your right on the money on that part. I'm just saying that you have to consider that anything that changes a cylinders shape also alters it's total volume. Wether or not the air is changed out by the piston during the fireing cycle, it's still there, and therefore counts in total volume of the cylinder. On a math point not nessiceraly on a mechanical point.
Truce OK?
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janesy
Dodge Dakota
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12/05/2005
18:19:37
| RE: 360 crank in a 318?
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How much do you want to spend on your 360 crank'd 318?It is not nearly as easy as it seams. at least not as easy on the pocket book.
First off you have to buy custom pistons. The only company that sells the size of piston needed is WISECO, everyone else will be custom, just like the WISECO's were. They are Forged, dished pieces and they are super light. The only other piston option are the mopar LA low compression slugs, but what the hell good is that. But..Good news is now there is at least one part # that will do the proper job. but they ain't cheap($1000+). Combine these Wiseco's with Eagle I-Beams and you will have a BOBweight of only 1735Grams, I beleive a VTEC honda runs at 1685, and stock is high 1800's.
Crank must be cut down to accept the large 318 journal size. Some thing to keep in mind when removing meat, is removal of strength. might want to look into radiusing, and nitrate hardening
As for the block the clearancing is minor.
Put together properly, you get the best of both worlds, 360 TQ, and super rev happy RPM. NA you will se 270/305 at the wheels. Add a blower and square it off at 382/382.
All in all, is it worth the $$ to do this. Don't know, but there is only a small handful of them out there, and only one I know of based on a MAGNUM block.
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toolfan
GenIII
12/08/2005
20:15:21
| RE: 360 crank in a 318?
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thanks for the info guys and jansey i was wondering because i have a 318 LA block in the garage.
[ and some mods to blow it up]
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janesy
Dodge Dakota
JOIN HERE
12/09/2005
19:32:10
| RE: 360 crank in a 318?
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The 318 block will be much easier to work with. There are much more piston options for them . The low comp units are for an LA block. For what it is worth, You can buy a 390 stroker kit for less. Only reason I went 349, is because I couldn't find anyone else with one. built right, a 390 will spin up faster than a 349 due to the shorter piston.
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toolfan
GenIII
12/09/2005
20:21:46
| RE: 360 crank in a 318?
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thanks janesy and the 318 that is setting in my garage will probably set for a while. i have no plans for that motor.
[ and some mods to blow it up]
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