Rod length? Piston speed?

thewrench3 · 05-30-2008, 04:19 PM

I run a four cylinder drag car myself. I have a 3.126 stroke and I changed from a 5.205 rod length to a 5.7 rod length. The 5.7 rod is 105 grams lighter and uses a small rod bearing diameter. The piston is 225 grams lighter and uses thinner rings. The longer rod engine makes more power up high- above 5000 rpm. the short rod motor makes more torque at 2700 rpm to about 3700rpm then the long rod engine makes more. The long rod engine is more particular about the cam timing. Overall I'm happy with the long rod engine. In the car the long rod engine runs a quicker et and more mph. My combination maybe different than yours the car is 2400 lbs. with me in it at race weight. Just talking from experience here.

05-30-2008, 04:19 PM	#12
thewrench3 Junior Member Join Date: Nov 2007 Posts: 14 Likes: 0 Liked 0 Times in 0 Posts	Re: Rod length? Piston speed? I run a four cylinder drag car myself. I have a 3.126 stroke and I changed from a 5.205 rod length to a 5.7 rod length. The 5.7 rod is 105 grams lighter and uses a small rod bearing diameter. The piston is 225 grams lighter and uses thinner rings. The longer rod engine makes more power up high- above 5000 rpm. the short rod motor makes more torque at 2700 rpm to about 3700rpm then the long rod engine makes more. The long rod engine is more particular about the cam timing. Overall I'm happy with the long rod engine. In the car the long rod engine runs a quicker et and more mph. My combination maybe different than yours the car is 2400 lbs. with me in it at race weight. Just talking from experience here.