Stroker 360 = sustained hi rpms?

[Mopar Mitch]

I've predominantly uesed my Chall T/A for medium speed autocrossing and typically run all in 1st gear for those events (3.23 gear), and usually run between 3500-6500 rpm (seldom into 2nd gear for an autocross, although it does make it more conservative... but I've always preferred the quick responsiveness within 1st gear up/down for course manuevering... repeated shifting is not good as it disrupts the stability of the car on the autocross course).  I also am more occasionally running hi-speed road course lapping events (will probably aim more toward the hi-speed events in my future, but still want occasional med-speed autocrossing), typically lots of 2nd gear (3000-5500) and occasional 3rd gear (up to 4500-5000).  Engine currently has stock hyd cam/springs, headers, six-pack, match-ported cast-iron heads... very reliable and great mid-range... able to hold hi-rpms up to ~6500 at rev-limiter.  I have a strong 727 tranny... and also a 3.55 that I could install if so wanted; am also considering a 2.9 rear gear for longer available 1st gear and slightly higher mph in each gear.  I'm used to revving my 340 up to 6500 at the highest for short moments.

SO.. my desire in the future is to build a stronger S/B... I currently have a machined squared/trued-block 360 (0.030 already bored but may need another 0.010 cleanup) aside, as well as an older 340 stock-bore also aside (wanting to pull the 15-20 pound heavier T/A block out and preserve it for future keeping).  I prefer to build a strong stroker 360 (4" stroke?) that can run long periods (repeated ~60 seconds of med-speed autocrossing  3500-6500;  also repeated 20-30 minutes of 3500-6000 road course sessions)... mild hyd cam... maybe .500 lift maximum?

Any thoughts of best crank/rods/ piston (pump gas... ~10:1CR)... cam selection?  Reliability for the lengthy hi-rpms is mostly wanted.  T/Anks ahead!  (Wiseco K1 products -- crank, h-beam rods, forged pistons -- is initially a preferred thought of mine).   OR Else... I could just go with a stock 360 crank/rods setup... but I like the idea of the bigger-inch strokers for more overall power/torque.  Again... T/Anks ahead!

[Chryco Psycho]

The Stroker makes way more sense to me . It reduces the mass with lighter pistons & rods & increases the torque with the longer stroke  this reduces the stress on internal parts & allows for more durability at high RPM so it seems to be a no brainer to me !!
 As for a specific parts list I do not have one , any steel crank should work , H beam rods with ARP bolts , lightweight Forged pistons , Diamond would be my first call , Wiseco ,is a great product also , many others like  Probe should have pistons , you may want to talk to Mancini & see what they offer as a kit .
 Cam, heads ,intake & carb is where the magic is you want something with a long flat powerband , I would look at the Lunati Voodoo seris  703 or 704 cam kits , with 1800-6200 or 2200-6500 powerband lift is free get more LOL just make sure you have matching spring pressures & 10* retainers & locks . Jegs has them for $260 with lifters . I assume you are still using J heads & 6 pack induction ?

[Mopar Mitch]

Thanks for the reply.  Those Lunati Voodoo cam specs appear to be outstanding and impressive!  Although I've removed the six-pack in the past for reduced weight for competition reasons (60 lbs overall setup vs 30 lbs overall with LD340/750 holley or Carter 625), I've recently put the six pack back on for car shows, etc... as everyone always wants to see the six-pack... its just about perfectly tuned using the Promax adjustable base plates and their center metering block... runs awesome mid-hi rpms (just that it adds 30 lbs to the front end of the car!)...   I run cast iron match-ported standard J-heads (2.02/1.6)... since I've got only a factory stock cam (429 lift).. I'm currently using the non-adjustable HD rockers... springs are also stock but equalized in pressure and height.... again... 6500 is the limit for peace-of mind... anything over that limit with the stock springs and potential float=damage!  I do have 273 adj-roker ars if so needed, as well as ported T/A heads aside with the factory offset rocker arms.    I'd eventually like to get some light-weight aluminum heads, but that can add considerable cost as well as alter my racing classes.... I'm content with the current iron heads.

I'm more concerned with the longer stroke (4") if the bottom-end can live for the lengthy time periods at hi-rpm... stock 2-bolt mains (probable 360 block), optional h-rods (although I do have a set of strong/prepped reconditioned stock I-beam rods)... again... ~45-60 seconds of repeated runs/tough autocrossing typical 1st gear 3500-6500 (maybe ~67-68-7K with stronger springs?), and then hi-speed road course repeated 20-30 minutes 3500-6000... what would be the weak spot for a hi-rpm s/b stroker?  Would the 340 block (not a T/A block, although I curently have one in the car) be better than the 360?

I typically assemble the engines completely by myself, but for a stroker I may have a reputable shop assemble it (at least the short block).    I'm enthusiastic about this and intend to eventually pull the current T/A 340 (block) to stash it aside for safe-keeping.  (also... I've always used a modified stock baffled oil pan that controls the oil pretty well, but I'll be installing one of the new Miloden road race low-profile pans).  Careful planning and wise-spending are always at issue with me... my dreams and desires continuosly rise in costs.
 

[Chryco Psycho]

I believe the stroker will be more durable at high RPM , less weight & more strength , the only downside if it is at all is the high piston speed otherwise everything will be stronger with the stroker .
 I do not really see an advantage to either the 340 or 360 block
I agree with the oil pan upgrade
 

[Mopar Mitch]

Thanks for your input.  I'm planning this over the long-haul (1-3 year plans, 5-year plan, etc).  I'll post again when I take a major step.  T/Ake care!

[Chryco Psycho]

Sounds like you have a lot more fun with yours than I ever have with mine 

[73restomod]

The one thing I always think about when building a stroker is the slug weight of the rotating assembly, which increases as the stroke is lengthened. 1 ft. lb. More in slug weight significantly increases  the force exerted on the block.  As Chryco says, it will decrease the force seen on the connecting rods and the wrist pins, which is a plus. I would get a block girdle if I were in your shoes, especially with a two bolt main, and a stroked crankshaft that will see sustained high rpm.

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[Mopar Mitch]

Thanks Chryco and Restmod!  I've owned this car since June of 1975... been predominantly and DOMINANTLY autocrossing it (SCCA/Solo II, and more recently hi-speed road course lapping events for social fun)... and many car shows, but I love racing it on any track (autocross or road course)!  I've always built my own engines and done most of the mods to the car by myself... coming out again to play after almost a ~10 year break from the action... but have always been a die-hard Mopar guy!  I believe the bug for Mo-Power is in me... light-weight rotating assembly, strong block... I'll still study the different options out there and see what others have been succesful with...   T/Anks alot!