[Stan Weiss]

HP per CI <---> HP per CFM of cylinder Head Flow

These are the two numbers being talked about to compare engine build quality / performance. To know which one is better for your needs you need to define what you are trying to do. I am looking for a single number that I can compare two engines to each other with out really knowing anything about those engines. While most here are talking about v8's I know there are a few in this section who are building 4 cylinders. So let use use a 400 ci v8 and a 200 ci I4 with the same 400 cfm head as are examples.

engine #1 - 400 ci v8 - 400 cfm head - 1000 HP
1000 HP / 400 ci = 2.5 HP per CI
1000 HP / 400 cfm = 2.5 HP per CFM of cylinder Head Flow

engine #2 - 200 ci I4 - 400 cfm head - 500 HP
500 HP / 200 ci = 2.5 HP per CI
500 HP / 400 cfm = 1.25 HP per CFM of cylinder Head Flow

You can decide which number helps you compare these two engine or any other engines.

Stan

[mike leech]

Glutton for punishment I see.

[BruceWilkie]

In lbs per cube classes the smaller motor wins potentially more often.... less frictional losses etc..

[Stan Weiss]

Originally Posted by mike leech

Glutton for punishment I see.

Mike,
Just trying to clarify for people who do not use these numbers what they show.

This is not the first time that I have been in threads where M D has posted (on other forums).

It is always the same with him, this is nothing new or surprising.

Stan