Experts: How much do you know about dynamic cmpression ratio?
03-19-2004, 12:06 AM
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Experts: How much do you know about dynamic cmpression ratio? Pleasee PM me with the response if possible, I'm sure that you don't like giniiing your hard eared info out to everybody. I know the forulma to calculate it, but what does it all mean? What is ideal compression taking into account intake opening events and octane?
03-19-2004, 09:06 AM
#3
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I know someone looking at this right now.
You will find as the engine gets bigger, DCR goes down... They are looking at a possible linear relationship in DCR vs displacement.
You will find as the engine gets bigger, DCR goes down... They are looking at a possible linear relationship in DCR vs displacement.
03-20-2004, 09:12 AM
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Question about DCR vs. Displacement J-Rod,
That sounds really interesting but I'm curious about your friends research: since the engine is in essence a large air pump, the larger it becomes, the more air it can suck into and out of a combustion chamber. Therefore for a given set of heads and cam and pistons, you'd think that it would be sucking more air out of the combustion chamber during operation than if you had a little engine and decreasing DCR. But it would also be sucking more air into the cylinder for combustion, therefore raising the dynamic compression ratio for a given set of heads and cam. So I don't really understand why the DCR would increase with Displacement, it seems it would be a washup. I know there may be some fluid dynamic reasons for the increase such as its easier for the air to leave than to enter a cylinder but other than that it would seem that their shouldn't be any relationship between DCR & displacement. Without giving to much away could you elaborate on his hypothesis for doing this trial. (sorry for the techninicality of this note)
That sounds really interesting but I'm curious about your friends research: since the engine is in essence a large air pump, the larger it becomes, the more air it can suck into and out of a combustion chamber. Therefore for a given set of heads and cam and pistons, you'd think that it would be sucking more air out of the combustion chamber during operation than if you had a little engine and decreasing DCR. But it would also be sucking more air into the cylinder for combustion, therefore raising the dynamic compression ratio for a given set of heads and cam. So I don't really understand why the DCR would increase with Displacement, it seems it would be a washup. I know there may be some fluid dynamic reasons for the increase such as its easier for the air to leave than to enter a cylinder but other than that it would seem that their shouldn't be any relationship between DCR & displacement. Without giving to much away could you elaborate on his hypothesis for doing this trial. (sorry for the techninicality of this note)
Originally Posted by J-Rod
I know someone looking at this right now.
You will find as the engine gets bigger, DCR goes down... They are looking at a possible linear relationship in DCR vs displacement.
You will find as the engine gets bigger, DCR goes down... They are looking at a possible linear relationship in DCR vs displacement.
03-20-2004, 03:25 PM
#5
Originally Posted by J-Rod
I know someone looking at this right now.
You will find as the engine gets bigger, DCR goes down... They are looking at a possible linear relationship in DCR vs displacement.
You will find as the engine gets bigger, DCR goes down... They are looking at a possible linear relationship in DCR vs displacement.