Various 427 Questions, New Member

[olddog]

Originally Posted by Excaliber

My old engine dynoed at 667 horse, open headers, BIG twin carbs, radical cam, 12.5 to 1 compression. Never dynoed the new one, I estimate I gave up about 150 horse power, maybe more. Now based on your theory/ET calculations that horse power ALWAYS equals a known ET and Trap speed I guess 800 horse would put me in the 9's? Unless you were STILL running tires that won't hook up and gearing where you shift into fourth AT the finish line or stay in third and 'run it out the back door'. What ever horse power you got if you can't hook it up, ET calculations are worthless.

True these formula assume good traction and propper gearing. Also true that with street tires and your origonal engine set up there was no way to hook it to the ground in the first few gears, as likely with the set up you have now. However at some point in the 1/4 mile you could likely hook all that power to the ground. From that point on the higher hp engine should have accellerated more so than the lesser hp engine. I didn't re-read the times you posted, but they were very close. I think the point is that the actual Hp to the wheels may be a lot closer than you assume. A 150 hp loss should have made a bigger change, even considering that the first few hundred feet is just burning up the tires.

From the time your first engine was dynoed and then stuck into a car and diddled and treaked, it may have had 50 hp less when you ran it down the track. Your engine building skills may exceed your modest expectations and it may have 50 hp more than you think. Now the differance is only 50 hp between the two. Factor in a 20% loss to the wheels and they are within 40 hp to the wheels.