If you are unfamiliar with NHRA or IHRA stock eliminator racing, cars are classed by using a formula that takes the cars weight divided by the advertised horsepower of the engine combo from the factory or the NHRA factored horsepower number if one has been established. Typically “horsepower” is added or the index is lowered on combos that run massively below their index (over 1.2 seconds) which means that competitors either have to add weight or they get their index dropped and have to figure out how to go faster yet again. It sounds complicated but it really isn’t. The engine you see on the dyno below is a 255hp rated 350 Chevy combo. This is a really common engine found in Camaros and other Chevrolet cars in stock and it is also found in the super stock ranks as well. We’re assuming this is a stock eliminator engine but we could be wrong. Anyway, the class where this combo would typically fall has an NHRA national record down in the low 11s and that is with a production weight car with a full interior. Clearly this is not longer making 255hp, right?
Stock has very stringent rules but it does allow blueprinting, any camshaft DURATION you’d like to use and every super tuning trick in the book. Guys use thin oil and all different manner of methods to eek out as much power as necessary, especially in class eliminations when the runs are heads up and your only hope is to be quick on the draw and first to the finish line. The dyno pull you are going to see was made at Patterson Racing in Kansas. These guys are among an elite group of highly respected drag racing engine builders that screw mills together for the likes of David Rampy and a host of others. The stuff they build is really good and competitive on a national level. They are racers themselves and Wallys are no strangers to their presence.
But enough out them…how about this little engine. Using the factory heads and many other factory pieces this little 350 makes some real noise. The horsepower number is not given but if you squint hard enough and count the bars on the right side of the graph is sure seems like it makes way more than 400 and closer to 500. We freeze framed the screen when the pull was over 7,500 RPM and we watched repeatedly at the torque gauge and saw 470 lb/ft at 5,000 RPM. Likely due to the restrictive heads, the power starts to tail off above 6,500 RPM or so.
It is rare to see one of these engines on a dyno where numbers can (kind of) be discerned. We’re openly guessing at some of it but the other numbers you can see. Pretty awesome stuff and it proves how good these guys are!
