How to predict Engine HP

[Guest Roaces]

I stumbled upon an interesting formula that calculates engine power based on stroke and bore, so I thought I'd share.

HP=B^1.65XS^.5XNXC

Hp=Horsepower, B=Bore, S=Stroke, N=Number of Cylenders, C=Constant

The constant represents the absolute performance value of the engine. This formula is good for calculating how much HP will be added by boring or stroking an engine. It also is pretty good at predicting how much HP an engine will make in race trim or after any ammount of modification.

For example, C for the VH45DE (Infiniti Q45 engine) is 2.52, A stock SBC would be in the range of 2.1. You might expect an NA engine in race trim to have a C of 4 or more. If anyone needs help applying the formula or has any questions, just ask.

[Guest Roaces]

After seeing a tremendously long thread that was basicly "GM VS Honda", this really helps put all that to rest (Original thread here). Hp/liter is an unfair measurment. Hp/liter means nothing because you can achive it with both bore and stroke, Bore if more effective in creating large HP numbers. So... If you use that formula I put up there earlier, them you can actually get a physical measurment of whose engines actually have a higher build quality. At this point I'm unbiased and just wanna find out how good or bad these engines are.

 

Honda D16A6 (CRX-Si), 109hp, 68hp/l, C= 2.43

Honda B16A3 (Del Sol), 160hp, 100hp/l, C=3.38

Honda H22A1 (Prelude), 190hp, 86hp/l, C=3.3

GM 5.7L LT1 (Trans am, Z28, 290hp, 51hp/l, C=1.97

GM 3.4MPFI (92-95 Firebird/Camero), 180hp, 53hp/l, C=1.97

2L Zetec (Focus SVT(Svt only)), 170hp, 85hp/l, C=3.12

2.3 Duratec (Ford Focus), 151hp, 66hp/l, C=2.56

4.6L (2005 Ford Mustang GT) 320hp, 70hp/l C=2.19

 

Conclusions: At first glance, it would seem that the SBC is a terrible engine, Considering that it lacks a 4 valve head and any type of variable technology, I would say a C of 2 is pretty damn good, actually. Which engine is best? Thats a relative term, Slam a F20C (S2000 240hp engine) in a Z and you might be able to get it below 2000lbs, Lower weight means that max cornering ability is increased, However, you are probably not able to now afford to feul it because you just spent $5000ish on a the engine alone. SO, the actual point of this thread is that I want to see a F20C-Z, Because it would be quite Grockalicious.

[Guest Magnum Rockwilder]

Who cares about hp/L or what bore and stroke it has? All that matters is what ends up at the wheels... and that's where the SBC comes in.

[Guest Roaces]

Cant agree with you more on that one, however, the thought of an all iron block and 2 valves per cylender scares us import people, so I went with a VH45DE, Its the all aluminum V-8 in the infiniti Q-45, with VVT and all those other goodies. Import engines can be big to, right? (well... medium at least)

[Corzette]

Ugh....LS1?????????????????

 

CZ