Small block strokers

[71ChargerRT]

I was looking around on one of the lesser sites Spawn hangs out on from time to time and one of the guys is building a 318 stroker. I think he's going 390" with it. Well that got me to thinking, I have a teener laying around and with a good set of heads that would be a suitable replacement instead of looking for another 340 or 360.


Their ad
"Street Kit 408”-416”
This is the kit we build our SB Street Krate engine with. We start with a cast Eagle 4” stroker crank, 6.123 long forged I-beam connecting rods w/bronze wrist pin bushings, Keith Black Hypereutectic pistons, Michigan 77 rod and full groove main bearings, and plasma moly piston rings, The rotating assembly is then balanced to a tolerance of less than one gram. This kit is recommended for applications under 500 HP. 340 and 360 blocks only. Available in 4.030, 4.040, 4.060, 4.070
Only: $1199
Forged pistons available for 318, 340 and 360. Bores sizes available up to 4.080
Additional: $175"


I think a forced induction small block stroker would be pretty sweet, especially in a Duster or Demon. :hmmm: I know where there is a decent '71 Duster with a slanty just sitting. Picking that up to mess around with would give me time to really tear into the Charger all the way AND fill my need for an old car to drive

 

[Dr.Jass]

A couple of points to consider:

None of those pistons will work in a 318, since its maximum bore is 3.95".

Stroking an engine an engine and adding forced induction is recommended only by the Department of Redundancy Department.

I would not recommend putting much boost to a cast crank, so why spend the money when forged-steel cranks of stock stroke can be had nearly for free?

This is money you could put towards your Charger. If a '71 Charger is your dream car, then put every dollar towards it. If not, start over. This is why I don't collect die-casts, Hot Wheels, emblems or any of that other stupid shit that doesn't help me towards my goal. Is the LeBaron my dream car? Not in the least, but I love sleepers and this may be the best one ever... and I happen to like the styling and interior, so I'm good with what I've got.

 

[Foggy]

I understand wanting to do something a little different from the norm, but a 318'' stroker wouldn't on my list. I know there is people out there doing it but...
You would be greatly hamstrung by valve size in the heads, and afterall, the heads dictate the potential. Find yourself a 340 or 360 block. The overall cost
would be about the same, and the end result would make you happier.

 

[Dr.Jass]

I think a 318 stroker would be a great truck motor with mildly-worked 308 heads (with stock valves) and a mild cam. Torquey as hell and great midrange... but for a HP car? No. I don't think there's enough bore there to notch to make use of the heads required to make serious horsepower. The deck surface is all-important on a small-block; why compromise what little you've got?

 

[v8440]

Hmmm, the ls motors with small bores don't seem to be hamstrung by shrouded valves too much. Is the placement of the valves in those such that they unshroud them better than a 318 would?

 

[Foggy]

IS motors? Wha that?
More exotic engines get into heavily canted valves and runners that 'coax' air flow to the 'centers' of the bores, to reduce the shrouding
effect of cyl. walls.
Valves open on cylinder centres on all LA engines. That is one of their strong points in making hp. And that helps unshroud the valves. But if you restrict
the cylinder size, then the shrouding happens again. Just because you can physically fit a valve into a head and block,
dosen't mean it will work well. The adjacent cyl. wall hampers air flow. That's why the hemi's make the power they do. Unhampered air flow with big honkin' valves.
You could notch the cyl. wall at the top of the cylinder opposite the int. val., but that is just a stop gap job at best, imo.
I'll be stretching my bore to 4.07'' bore, just to make use of the Indy heads, and their larger int. valves, and the valves already fit my .03'' bore.
I was cautioned that min. size would be the .07 inches cyl. size, and any smaller would negate, or reduce the power change to in heads. And the hp and torque
just takes off after 417 cube engine.............
Same thing happens with the smaller heads and valves. The sweet spot seems to be the 4.04'' bore for the 2.02 valved heads, and power seems
to climb as well, when the cyl. is stretched, though not as dramatically as the bigger valved heads.
I wouldn't be opposed to adding a little juice to that combo as long as you have good pistons
Make it easy on yourself and start with a bigger bore block.