modded 318 or 390 stroker?

[charger318]

If u were going to build a 318 would u just build the motor up with 10.5:1 CR, aluminum heads, air gap intake, header and exhaust, solid lifter cam 230 int 236 exh [email protected] 488/501 lift.

Or do all the same plus a 4" stroke scat crank and scat ibeam rods .030 over bore? Do you think it would be worth the stroker kit added to build?!?! And if so how much more power u think it would get?

 

[rumblefish360]

I'd do the stroker kit if the money is not a problem for the mass amount of added torque. No doubt. The Edelbrock heads should be ported for the extra cubes. How much power can be figured on a desk top dyno for a decent est. on what could be if you can install and degree the cam in right and tune it really well.

Do yourself a favor and step up to tti or Hooker Super Comp (1-3/4 tube) headers.

While I like the 318 engine, in a B body, it is just a people mover. In an A body, it can be fun since your moving a lot less weight.

 

[Cranky]

Well, I'm a big block guy and have several in my shop. The 390 setup should push your car around pretty well but so would a 383 for a lot less money imo. Also, I like several things of the big block vs the small block like the external oil pump, insert style water pump, distributor up front, 5 bolts per cylinder on the heads, dry intake and having a larger bore vs stroke on the low decks. However, installing a big block into an A body is a lot tighter vs the small block so I generally lean towards smalls in the A body cars. That said, if I was going to build a SB stroker, I'd go for the largest bore I could find and that would entail using the 340. Next choice would be using the 360 since they are usually much cheaper to buy vs the 340 AND they use the 4" bore which just about every known manufacturer has produced an engine with a 4" bore which makes piston choice wide open and also makes that cheaper. Not that many build 318 strokers vs 340 and 360 so usually, prices for pistons etc will generally be higher. If you already have the teen, then you can save a few bucks but imo, an engine with a larger bore will generally produce more power vs one with the smaller bore. A small bore long stroke engine (like the slant 6) makes good torque but a large bore short stroke engine will makes good horsepower whereas a big bore long stroke engine does both. However, you can make a large bore short stroke engine make more power by turning it more rpm. Generally you don't want to do that so much with small bore long stroke engine plus the small bore engines have a tendency to shroud the valve more because of the bore size. Thoroughly cornfused now?

 

[charger318]

I know what you mean . Ya I considered the bb my dad has an extra 383 bored .060 over, but when considering k member or motor mount adaptors, big block trans, driveshaft, rearend. She adds up pretty quick. I already got a Very good running 318 in the charger all stock, so I figure why not stroke it to a 4" crank bore it .030 found Campbell pistons 3.940 that give 10.5 under a 64cc chamber for the long stroke crank, for $344 with moly rings. Just wondering if anyone has building a 390 stroke to see if they were happy or dissapointed with results.

 

[Budnicks]

I know what you mean . Ya I considered the bb my dad has an extra 383 bored .060 over, but when considering k member or motor mount adaptors, big block trans, driveshaft, rearend. She adds up pretty quick. I already got a Very good running 318 in the charger all stock, so I figure why not stroke it to a 4" crank bore it .030 found Campbell pistons 3.940 that give 10.5 under a 64cc chamber for the long stroke crank, for $344 with moly rings. Just wondering if anyone has building a 390 stroke to see if they were happy or dissapointed with results.

I agree with most of what Cranky said too... I had built a 4" crank 318/5.2ltr Magnum/390ci Eagle cast crank & I-beam rod, 0.030" over 3.94" bore w/4" stroker kit from Mancini Racing like $1500 + $300 for internal balancing {like $1900+ $300 for forged crank & H-beam rods} I used the factory R/T hyd. roller camshaft & 1.7 Harlan Sharpe roller rockers, internal balanced so I could use my original flexplate trans converter damper etc., from the 5.2ltr Magnum/318ci to save a few $$$, home ported & short side radius, bowl job iron 2.02" R/T Magnum Iron Heads, that oil thru the push rods not shaft type like the LA SB valve train components, it was a commuter truck/fun driver, not really a racer, years ago now in my old 99 2wd Dakota SLT-R/T clone, it was well worth the money, lots of torque, especially compared to stock 318/5.2... I'm considering doing it with my current daily driver 4x4 99 Dakota SLT 5.2lrt/318ci Magnum auto, when the time comes to rebuild her, but it's a much newer platform... IMHFO if I had an older car/truck pre 1993, I'd do a B-series Low deck 383-400 slightly smaller lighter shorter narrower style BB wedge, for about the same money or even much less, if you shop it out right...

- - - Updated - - -

find a good machine shop/machinist or just buy a short block assembly, isn't a bad idea either, if you want to retain the small block, but now with BB 390ci+ displacement...

 

[charger318]

do u remember the specs of cam @.050, compression, gearing, exhaust headers or stock manifolds, intake things like that and did you flash ecu for changes?

 

[Budnicks]

do u remember the specs of cam @.050, compression, gearing, exhaust headers or stock manifolds, intake things like that and did you flash ecu for changes?

Turned my 230hp 318 into a estimated 20mpg torque monster probably somewhere like 400hp/390ci... Edelbrock 1-3/4" chrome bolt-on truck shorty headers stock head pipe 3" cat back Flowmaster, 3.94" bore, 9.8:1 compression, w-0.040" thick Felpro perma-torque head gaskets, 3.90:1 9.25" rear gearing, Hypertech engine tuner w-91 octane tune {I sent my tuner to Hypertech told them what I had changed, they changed the parameters} , stock magnum intake, cleaned intake & head ports, went up IIRC w-52lb MPI Viper injectors {don't quote me on that, got them from F&B Throttlebody} AEM 4" air tube & gauze type air filter & air box, 1.7:1 Harlan Sharp rockers, stock length Magnum 5/16" ball/ball Smith Bros. chrome-moly push-rods, Magnum Cast Iron R/T heads #P5007141 2.02"/1.65" & R/T Camshaft - #P5249549 - advertised duration 260*int/264*exh {I don't remember @ 0.050"}, 55* overlap, 109* centerline, 0.458"/0.467" gross lift w-1.6:1 rockers {w- HS 1.7:1 rockers it's appr. 0.486"int/0.496"exh gross lift}, valve springs were #P5249464, MP moly retainers & locks, MP Teflon seals, MP timing set, all Mopar Performance parts... I also bought all ARP hardware, never reuse the original hardware if you want it to last/live... there's a couple of great books MP Engines 9th edition & MP Magnum Engines 2nd edition, both have a bunch of proven combos, that will work well with stroker's too... many other great books on the subject

 

[696969]

Turned my 230hp 318 into a estimated 20mpg torque monster probably somewhere like 400hp/390ci... Edelbrock 1-3/4" chrome bolt-on truck shorty headers stock head pipe 3" cat back Flowmaster, 3.94" bore, 9.8:1 compression, w-0.040" thick Felpro perma-torque head gaskets, 3.90:1 9.25" rear gearing, Hypertech engine tuner w-91 octane tune {I sent my tuner to Hypertech told them what I had changed, they changed the parameters} , stock magnum intake, cleaned intake & head ports, went up IIRC w-52lb MPI Viper injectors {don't quote me on that, got them from F&B Throttlebody} AEM 4" air tube & gauze type air filter & air box, 1.7:1 Harlan Sharp rockers, stock length Magnum 5/16" ball/ball Smith Bros. chrome-moly push-rods, Magnum Cast Iron R/T heads #P5007141 2.02"/1.65" & R/T Camshaft - #P5249549 - advertised duration 260*int/264*exh {I don't remember @ 0.050"}, 55* overlap, 109* centerline, 0.458"/0.467" gross lift w-1.6:1 rockers {w- HS 1.7:1 rockers it's appr. 0.486"int/0.496"exh gross lift}, valve springs were #P5249464, MP moly retainers & locks, MP Teflon seals, MP timing set, all Mopar Performance parts... I also bought all ARP hardware, never reuse the original hardware if you want it to last/live... there's a couple of great books MP Engines 9th edition & MP Magnum Engines 2nd edition, both have a bunch of proven combos, that will work well with stroker's too... many other great books on the subject

I'm greatly impressed and intrigued by this. I got a 318 lightly modded with Eddy 4BBL and intake, Headers. Would like to better my low end, maybe modify the rear. Can you recommend a good kit? I would like to play with this motor for a little while til I get the funds for an engine swap, esp. since it has such low miles.
Post a pic of your 318 some time.

 

[charger318]

as far as brand I would stick with scat, not only here but other sites say same thing scat cast crank , scat I beam rods, that combo people say u don't have to clearance the block to fit. Pistons I like are, the Campbell stroker pistons with 1.460 -5 cc ends up being 11:1 cr under 64cc combustion chamber.

 

[rumblefish360]

Sonic check your block. You MAY be able to go further than the normal overbore.
At the moment, I can not remember the name of the company, but they routinely take 318 blocks to a 4.00 bore IF they "sonic" check out good. And yes, they install a 4.00 crank.

 

[charger318]

Ya some can go to 4.00 bore but pistons might get pricey because u need a 4.00 piston with a 1.465 compression height because of increase stroke

 

[Budnicks]

I'm greatly impressed and intrigued by this. I got a 318 lightly modded with Eddy 4BBL and intake, Headers. Would like to better my low end, maybe modify the rear. Can you recommend a good kit? I would like to play with this motor for a little while til I get the funds for an engine swap, esp. since it has such low miles.
Post a pic of your 318 some time.

No photos sorry & I no longer own that truck, it was near 10 years ago now, it would have looked like a Magnum truck engine with an AEM air intake kit & headers... Looks pretty stock from the exterior... I guess I could take a photo of my current 99 4x4 Dakota SLT 5.2ltr. has the same airbox/intake kit... It's "not" a real inexpensive way to go, probably $2k+ min., more for a H-Beam & Forged crank, but if you want to keep a sb in it, it's a great way to make tons of torque... you will need a competent machinist too... but the only "sb stroker" kits I've ever tried, was an "Eagle" supposedly not the best, according to some, but far from the worst too & relatively affordable, I never had any issues at all... They were a Mancini Racing kit, {I would highly suggest to call & talk to them 1st, see what's all in the kits now, contact a good machinist & get pricing} so that's the only one, that I could personally recommend... your stock heads will be a big choke point too, unless they are ported, it can still work, it'll just be more of a lower rpm grunt motor, with a longer stroke, forged pistons, good rods, good rings & bearing... you will probably need more carb/fuel too...

 

[rumblefish360]

Ya some can go to 4.00 bore but pistons might get pricey because u need a 4.00 piston with a 1.465 compression height because of increase stroke

No! Price goes down because it is now the standard 4.00 bore. AKA 360.

 

[charger318]

ya it is a 4.00 bore which is a stock 360 bore, but they are not a stock 360 compression height. stroker pistons are shorter because of the extra stroke there for u cant buy stock 360 pistons they would come out of block almost 1/2 an inch. so u are looking for 4.00 bore but 1.465 cr height insteed of 1.810 which would be for stock 3.5 stroke crank. ive never seen stock bore size with shorten cr height

 

[rumblefish360]

No no no, your not understanding, the popular striker pistons for small blocks starts at 4.00. This is for Chevy, Ford and MoPar. This popular stroke (4.00) is seen in Chevy and Fords as well. This makes the piston fairly easy to reproduce over and over again with small changes in skirt and valve relief.

The slugs are of course, not dirt cheap like replacement slugs and of course I totally understand the idea of stroking an engine as well as slug height differences between stock and a striker crank.

This is far from my first rodeo ride.