|
318 to 390?
#1315239
10/04/12 09:05 PM
10/04/12 09:05 PM
|
Joined: Oct 2012
Posts: 15
Illinois
Tinmans21
OP
member
|
OP
member
Joined: Oct 2012
Posts: 15
Illinois
|
Ok I have an 85 Dodge diplomat salon 4 door that im making into a sleeper. I want to take the 318 i have an bore it .40 over an make it a 390 stroker. I've read that it is possible to make 360 heads flow better than the stock 340 x heads heres the link http://www.moparmusclemagazine.com/techa...ng/viewall.html So i was considering doing the exact same thing an putting them on the 390 stroker. As for a cam and intake im not sure. I want the car to be streetable but also have a hefty amount of power. The car is planned to be a sleeper an intended to blow the doors off of teenage kids who think they are on top of the world. I also have a 650 holley double pumper laying around. Would that be to much depending on the cam an intake? Does anyone have experience with this kind of motor build an have advice for cam an intake based on what iv said? Please any advice is amazing!!!
|
|
|
Re: 318 to 390?
[Re: Tinmans21]
#1315242
10/05/12 01:01 AM
10/05/12 01:01 AM
|
Joined: Jan 2003
Posts: 3,943
Melbourne.....Oz-land
Moparmal
master
|
master
Joined: Jan 2003
Posts: 3,943
Melbourne.....Oz-land
|
Ran a 392 for 18 mths till the Eagle cast crank let go. I used ported 360 heads peak flow to 240cfm at .550 lift. Off the shelf headers, M1 SP off the shelf, comp xs282s sold (520 , 245@.50)3.89 gears, 3400 stall, RMVB. 800 AVS carb, 3650lbs with me in it. Ran a best of 12.3 at 111mph with a dogs$&t 60 ft of 1.86, Loved the torque for street duty and there was def more in it. Just use a decent brand crankshaft and forged slugs.....Icon 846/847 are good. 
67 RO23 clone with 6.1 SRT Hemi and dual quads. Soon to have Drag Pak induction and Throttle body.
|
|
|
Re: 318 to 390?
[Re: Moparmal]
#1315243
10/05/12 10:49 AM
10/05/12 10:49 AM
|
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
|
don't use an eagle cast crank, go with a scat. balance it to 360 external if you need a lot of heavy metal for internal balancing skip the 360 heads, go straight to magnums...either junkyard pieces or these from hughes http://www.hughesengines.com/Index/produ...mp;partid=25702if you go stockers, use the hughes #1110 springs and their retainers anyway.. your '85 should be a roller block/cam. you'll need new magnum roller lifters (about $85 set) since the '85's don't have pushrod oiling provisions. for a heavy car like a dippy (I hotrodded a 5th ave) don't go too big on the cam. look for a roller cam in the [Email]218-224@.050[/Email] range, with about .340" lobe lift (nets approx. .540" valve lift). edelbrock RPM air gap, and I'd probably look at the new demon thermoquad clones for street use, or an 800 cfm eddie AVS. run headers, and this should be a 425-450hp combo pretty easily. if you want fun, I'd use an iron case A body A833OD manual and 3.23's or 3.55's out back. should be a low, low 13/high 12 second car.
Last edited by patrick; 10/05/12 10:51 AM.
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
|
|
|
Re: 318 to 390?
[Re: dizuster]
#1315251
10/08/12 09:06 PM
10/08/12 09:06 PM
|
Joined: Jan 2003
Posts: 7,978
Bethel Ct
AdamR
master
|
master
Joined: Jan 2003
Posts: 7,978
Bethel Ct
|
Quote:
You'd probably be further ahead money wise just building a stock cast crank 360. I wouldn't waste the time on a stroker 318 when 360's are so plentiful.
why is that ? most guys already have the 318
|
|
|
Re: 318 to 390?
[Re: AdamR]
#1315252
10/08/12 11:45 PM
10/08/12 11:45 PM
|
Joined: Jan 2003
Posts: 3,943
Melbourne.....Oz-land
Moparmal
master
|
master
Joined: Jan 2003
Posts: 3,943
Melbourne.....Oz-land
|
I agree...and furthermore....... Its funny how the extra 32 cubes between a 318 and 360 are "to die for", but the xtra 32 cubes between a 360 and 392 don't count for much...... Of course this position is only ever held by those who've never run a stroked 318 on the street... 
67 RO23 clone with 6.1 SRT Hemi and dual quads. Soon to have Drag Pak induction and Throttle body.
|
|
|
Re: 318 to 390?
[Re: Moparmal]
#1315253
10/08/12 11:52 PM
10/08/12 11:52 PM
|
Joined: Apr 2005
Posts: 12,271
Overpriced Housing Central
RobX4406
I Live Here
|
I Live Here
Joined: Apr 2005
Posts: 12,271
Overpriced Housing Central
|
Quote:
I agree...and furthermore.......
Its funny how the extra 32 cubes between a 318 and 360 are "to die for", but the xtra 32 cubes between a 360 and 392 don't count for much......
Of course this position is only ever held by those who've never run a stroked 318 on the street...
Math is hard...
|
|
|
Re: 318 to 390?
[Re: RobX4406]
#1315254
10/09/12 01:46 AM
10/09/12 01:46 AM
|
Joined: Jan 2003
Posts: 3,943
Melbourne.....Oz-land
Moparmal
master
|
master
Joined: Jan 2003
Posts: 3,943
Melbourne.....Oz-land
|
Quote:
Quote:
I agree...and furthermore.......
Its funny how the extra 32 cubes between a 318 and 360 are "to die for", but the xtra 32 cubes between a 360 and 392 don't count for much......
Of course this position is only ever held by those who've never run a stroked 318 on the street...
Math is hard...
You should be having my day Cracked.....err Rob....If I could ship it FedEx to you I would.......:p
|
|
|
Re: 318 to 390?
[Re: RobX4406]
#1315255
10/09/12 02:00 AM
10/09/12 02:00 AM
|
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
DaytonaTurbo
Too Many Posts
|
Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
|
Quote:
Quote:
I agree...and furthermore.......
Its funny how the extra 32 cubes between a 318 and 360 are "to die for", but the xtra 32 cubes between a 360 and 392 don't count for much......
Of course this position is only ever held by those who've never run a stroked 318 on the street...
Math is hard...
It must be, because 360-318 = 42 cubes, not 32. Buy a core 360 for $300, then add in your new pistons, redone rods, recondition crank, new bearings and you're easy at the 1k or over mark. Could kick in a bit of extra cash and have stroked the 318 from the start. Which is worth it is up to you. I thought I saw complete 390 kits on sale for 1300 or 1400 bucks.
|
|
|
Re: 318 to 390?
[Re: Moparmal]
#1315256
10/09/12 02:25 AM
10/09/12 02:25 AM
|
Joined: Apr 2005
Posts: 12,271
Overpriced Housing Central
RobX4406
I Live Here
|
I Live Here
Joined: Apr 2005
Posts: 12,271
Overpriced Housing Central
|
Quote:
Quote:
Quote:
I agree...and furthermore.......
Its funny how the extra 32 cubes between a 318 and 360 are "to die for", but the xtra 32 cubes between a 360 and 392 don't count for much......
Of course this position is only ever held by those who've never run a stroked 318 on the street...
Math is hard...
You should be having my day Cracked.....err Rob....If I could ship it FedEx to you I would.......:p
Just having a bit of fun. Hope your day gets better,
|
|
|
Re: 318 to 390?
[Re: DaytonaTurbo]
#1315257
10/09/12 07:36 AM
10/09/12 07:36 AM
|
Joined: Jan 2003
Posts: 3,943
Melbourne.....Oz-land
Moparmal
master
|
master
Joined: Jan 2003
Posts: 3,943
Melbourne.....Oz-land
|
Quote:
It must be, because 360-318 = 42 cubes, not 32.
yeah got that - argument is still valid -
Cubes has always been the "pitch" the 360 boys bring to the mound - but when the 318/392 combo gets mentioned torque per cui is suddenly "relegated to the minors".
I prefer this equation:
392 cu. in. ...1 hp per cu. in....392 hp (4" stroke)(torque Monster)
360 cu. in. ...1.08 hp per cu. in. 392 hp (3.580 Stroke)(medium Torque)
340 cu. in. ...1.152 hp per cu. in 392 hp (3.310 Stroke)(no torque)
318 cu in. ...1.23 hp per cu. in. 392 hp (3.310 Stroke)(no torque)
Which is most streetable to run and easiest to achieve ?
Batter up! 
|
|
|
Re: 318 to 390?
[Re: Moparmal]
#1315258
10/09/12 10:44 AM
10/09/12 10:44 AM
|
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
|
one HUGE advantage of stroking the 318 vs. building a 360 is his '85 318 has a factory roller cam. that allows you to use either a reground factory or an aftermarket hydraulic roller cam with the very depandable and cheap OEM hydraulic roller lifters.
and a dippy is a heavy car. my 5th ave was 3950 lbs w/o me once I added the A500 tranny, big sway bars, 8 3/4" rear and 5 leaf rear springs (and deleting all the emissions crap, going to an aluminum intake). Torque is your friend, and torque is directly proportional to displacement. built identically except for displacement, I'd expect the 390 CID stroked 318 to make ~8%, or about 25-30 more lb-ft of torque than a 360.
the economics of it are use your existing 318 block, and spend $300 on a SCAT 4" crank, or spend $300 on a 360 core motor....otherwise the build costs will be very similar if you were planning on aftermarket pistons/rods/heads
for a car like this, that's going to be a street car primarily, don't look at peak HP, look at ave torque and torque peak, and let the HP fall where it may. a 420HP engine with say, 450 lb ft peak torque at 3500 RPM, with over 90% available from idle to 5000 RPM will probably feel stronger than a 475HP motor but with 450 lb-ft peak at 5000 RPM and only 70% of peak torque available off idle and 90% not available until 3000 RPM...
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
|
|
|
|
|
Just my luck, has nothing to do with what the engine was.
