rickwrench
Famous Member
I've watched a couple of my buddies go nearly broke spending a small fortune to build long rod motors for their street cars. Because "long rods make more power". And then skimp on head work! I've also watched as mgb-V8 guys gave up over FIFTY cubic inches becuase, get this, 240 cid revs "way better" than 293 cid (or even 331 cid Rover blocks). Idiots. Sure, a 240 cid, extremely long rod (2.19/1 r/s ratio) motor can rev to 7200 rpm quickly and safely, while my 331 stroker (1.55/1 r/s ratio) will hit the same max piston acceleration at 5700 rpm. But I'll bet I'll have at least 150 lbs/ft of torque on him at 3000 rpms. See ya later!
ALWAYS build for cubes and airflow in a street motor.
Shouldn't have to go into airflow on this forum, ha ha, ........loghead........wheeeeeeze..... tell 'em Jack!
On the other hand, in money-no-object, displacement-restricted racing classes, the differnce is apparently significant enough to matter. Heck, 2% at 140 mph is almost three miles an hour. You win the race, if you don't crash or have a two dollar part break and wreck your forty grand engine.
For me, when it comes to building for street performance, I focus on displacement, getting as much fuel/air into the cylinders as possible, and then lighting it with a long, hot, spark. That's the order in which I spend money, stroke, head(s), exhaust, intake, cam(s), and ignition. There was a time when I used to dwell obsessively on R/S ratios. But now, on a street car, the only reason for me to build w/ longer rods and shorter pistons would be:
piston/crank clearance issues, or,
if they were free (and then just to raise the redline).
Unless... I could trade them for better heads, or an intake, or a supercharger...
My two cents.
Rick(wrench)
ALWAYS build for cubes and airflow in a street motor.
Shouldn't have to go into airflow on this forum, ha ha, ........loghead........wheeeeeeze..... tell 'em Jack!
On the other hand, in money-no-object, displacement-restricted racing classes, the differnce is apparently significant enough to matter. Heck, 2% at 140 mph is almost three miles an hour. You win the race, if you don't crash or have a two dollar part break and wreck your forty grand engine.
For me, when it comes to building for street performance, I focus on displacement, getting as much fuel/air into the cylinders as possible, and then lighting it with a long, hot, spark. That's the order in which I spend money, stroke, head(s), exhaust, intake, cam(s), and ignition. There was a time when I used to dwell obsessively on R/S ratios. But now, on a street car, the only reason for me to build w/ longer rods and shorter pistons would be:
piston/crank clearance issues, or,
if they were free (and then just to raise the redline).
Unless... I could trade them for better heads, or an intake, or a supercharger...
My two cents.
Rick(wrench)
