318 to 390 stroker

[charger318]

hey everybody im real interested in the 390 stroker and was wondering if anyone here has built one and if it turned out to be what you expected, more, or less?
and if you did what did you use? my plans are procomp aluminum bare heads 2.02 int 1.6 exhaust 171cc ports 64cc chamber, 273 adjustable rockers, eddy air gap intake manifold, comp cam sx268s, double roller timing chain set, 750 cfm holley vac secondary, 1 5\8 headers. so interested in what you guys think would be going in 74 charger se.

 

[Supershafts]

I'd use a w2 and m1, and id even use 1 of those speed pro 190cc heads over the pro comp, but the w2 is the 1st choice, don't know what the spec are for that cam but id be looking roller at 240@50 area on a 110, 550 lft area, be prepared to do some clearance on the block for the valve

 

[charger318]

With the .030 over bore I think it will help with valve shrouding of intake valve. The pro comp bare head is what air wolf use the make there heads with there porting valves and spring set plus chamber clean up so that's why I went with bare pro comp with my own parts. The cam is like 234/238 dur @0.050 and 484/501 lift. Already set up with solid cam roller would be nice but with roller also have to worry about push rod clearance through head. I was just wondering if anyone here has done this stroker and what they ended up with.

 

[Supershafts]

Supposedly the AW heads are 220 intake which is better, id add 1.6 to that cam and still use the M1

 

[Cranky]

A buddy of mine has a 390 stroker with a turbo on it in a 94 Dakota. Runs low 11's and it's pretty tame on the street.

 

[charger318]

Did your buddy use the crast crankshaft or forged? I know the mopar performance cast 4" crank is made by scat and I was leaning towards that but the long stroke with good gearing and traction makes me alittle nervous ive seen people online break the cast in half but they also were spinning motor 7250-7500 rpms when the cast crank is rated up to 6500 rpm, that could be why?

 

[rumblefish360]

It's really not the RPM that kills the crank, it is the amount of power it is handling. So long as the whole assembly is balanced right, all it'll need is a good amount of oil to live. The RPM ceiling is more of a valve spring issue. Not enough. The cam profile has a hand in this. Also, what do you plan on spinning this stroker to? That cam you have is going to max out in power well before the 6500 mark.

I'd also look into some head work.

 

[charger318]

2000-6000 is operating range of camshaft so 6000-6300 rpm shift points, heads are 171cc ports 64cc chambers, 2.020 int 1.600 exh, 11/32 stems, probably do some ports clean up and shaping, bowl blending, and unshroud vavles, comp cam 986-16 double springs good for .560 lift with 273 adjustable rockers

 

[Supershafts]

Not enough heads, 171cc needs to be in the 200's, work on the int or sell them and get better heads.

I wouldn't worry about the crank, as long as it's not eagle, went from eagle to scat on the last broken eagle, no issues so far.

I wouldn't use the 273 rocker, use a 1.6 rocker since the cam doesn't have the lift

 

[charger318]

I agree with the ears gonna port them out to 200cc range. Might hold on to the rockers I know what u mean about the 1.6 to make up some lift but she's a street car anyway so if I lose out on 20-30 HP. But keep some cash in the pocket for **** breaking which u never know I'm OK with that maybe down the road throw some 1.6 ration roller to rockers at it.

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So what car and engine combo do you run?

 

[Cranky]

Did your buddy use the crast crankshaft or forged? I know the mopar performance cast 4" crank is made by scat and I was leaning towards that but the long stroke with good gearing and traction makes me alittle nervous ive seen people online break the cast in half but they also were spinning motor 7250-7500 rpms when the cast crank is rated up to 6500 rpm, that could be why?

Cast crank. He also built a 360 stroker using the 4" cast iron arm....turn it 7000 but I'm not sure what he's turning the teen....