J head help needed.

Hi,

Im working on a J headed stroker, of course there are better performing castings however for this project its J heads.

This is a street driven car down to the mopar hydro cam with deep gears and a good vert.

What ive got is a real nice set of castings, a good three step bowl cut on the intakes for 2.02s and a nice multi angle cut on the ex.

So with the oem guides I need to source some chrome stem valves, all I have on hand are SS ones and they dont seem to play well together.

As well I need to know what are the best valve seals to use on these oem heads?

Thanks in advance!

Most aftermarket SS valves stems are hard chrome plated.

Hmmmm... That would work, ive got to look at what ive got, they came in another set of heads (new) but im not sure on the brand.

As far as seals go? I didnt add this is a single spring for the cam.

Thanks for the help, im not very skilled on oem heads on what will interchange.

It looks like what ive got on hand are manley severe duty valves that have chrome stems, I thought they were really cheap valves and never ran the PN on them.

I think the regular black viton "umbrella" type seals will work fine, the larger ones on the intake stems cuz they need more protection cuz of the intake vacuum

Good ol Felpro has a kit with all 16 for little money at rockauto. While you're in there, let me be the first to say cut the valve guides down on the top side to give more room for higher lifts, there isn't a lot of room in there stock. Also, probably the best single spring is the Hughes 1110.

That 1.600 or 1.625 installed height plays heck with any kind of lift. For example the Crane 833 springs I'm using are good for about 0.470 lift given the 0.060" allowance for coil bind.

R.

Thanks, I sincerely appreciate the help, alot of oem things im not well versed in.

DD, them are the exact springs I have.

The cam is the simple mp 484/282

I have several sets of J X heads but this set has the three angle bowl plunge cut and they look pretty good.

I say this is a real street car because it is, the hydro cam, the newer mp 3x2 setup because its a car to be driven, far and long.

$4:56 rear, vert flashed to 5200 with a 630hp stroker so I hope this vert mellows out enough to use it.

So Id like to do the minimal bowl/port work that has the highest returns without going thin enough ANY place to make there lifespan shorter.

I will post some pics of diff bowl configs ive got for some opinions on what would work best in this case.

THANKS!

You might Google it & I think Dulcich has some good porting articles

Reaching your goal of 630 HP with the parts you have selected is probably not possible, maybe with a NOS system
I'm in the middle of starting a 340 pump gas stroker motor that will be either 416 or 418 C.I. motor with a set of Eddy RPM heads and Eddy Air gap intake with a good high CFM carb., mild Comp Cams hydraulic street cam(XE284HL) and a decent set of adjustable rocker arms. I'm expecting from 475 to 510 HP on Oregon 91 octane non ethanol pump swill.
The last pump gas street stroker 340 motor I built and dyno tested made 527 HP with a 1050 CFM Dominator carb on a set of mildly ported W2 heads and the matching Mopar W2 single plane (Eddy brand)intake, big solid lifter Comp Cams, that motor made 14 HP less with a 850 CFM double pump carb with no dominator carb adapter spacer on the intake The six pack set up well tuned may add 10 to 30 HP, maybe not
That was 12 or more years ago also .
IHTHs

I thought the stock installed height was more in the 1.68/1.69" range on the X or J heads, the shorter heights are the magnum heads...correct me if I'm wrong.

Here is what ive got now, I actually bought these off the parts board here and my main concern was the oem guides and they are well within spec and the heads seem to have a low/easy service life so far.

This is the bowl cuts, im not up on the way they cut for the 2.02s, ive a set put up I know started out as 1.88 but im not going to spend a day looking for them.

Really I know there isnt a high value on these heads but its almost a shame to cut on a nice untouched head.

AS well the stroker is 422 inches, maybe during the clean up I can add 20-25ccs to the port volume.
I think I got a set of 2.055 intakes as well sitting around.
Im shooting for a stout runner, not the race winner and as well I think I can run up to a 300 shot through my plate kit for a good equalizer.

I did this like 20 years ago, just a bowl cleanup and gasket match on a J head and as a 360 with a 550 lift comp and flattops it hit 428hp 425tq on a reliable dyno.

My lungs are in very poor shape so the less overall grinding I end up doing will also help me.