4-2-1
Posted: March 3rd, 2010, 9:39 pm
Guy,
As you know I was on a market for some time for a 4-2-1 for my new engine.
I recently managed to gt one. It was apparently taken off a Racing engine from the US. The extractor is on good condition and first of all it is not one of the new constructions that look like antlers of a ram. It also is not made of short stretches of bent pipe but hot formed original.
For some reason I do not like or trust the shiny steel ones made of dozen of elbow connectors.
Anyway , I have just measured my new acquisition : primaries are internal diameter of 36mm and 48 cm length while secondaries are 42 internal diameter and 60 cm length.
It seem these are neither old theory "proportions" (short primaries/long secondaries) not new theory ( short primaries,long secondaries).
I have ma de a calculation of capacity of both primaries and secondaries, Primaries have capacity of 488 cc and secondaries have capacity of 831 cc. The secondaries capacity is 70% larger than the capacity of the primaries.
Now, I have no knowledge of the gas flow theory , but remember Einstein saying that every good theory should also look elegant. The theory is not look elegant is inadvertently wrong. 70% increase of volume increase from primaries to secondaries does have a touch of elegance.
Not pretending that have the knowledge to make the judgment , it would be presumptuous to make such claim. Will it provide max performance of a highly tuned engine - no clue , but I would expect ( and hope) it to work nicely ...
What do you think of such proportions, Guy?
Miro
PS and how do you like the elegance test of a theory...?
As you know I was on a market for some time for a 4-2-1 for my new engine.
I recently managed to gt one. It was apparently taken off a Racing engine from the US. The extractor is on good condition and first of all it is not one of the new constructions that look like antlers of a ram. It also is not made of short stretches of bent pipe but hot formed original.
For some reason I do not like or trust the shiny steel ones made of dozen of elbow connectors.
Anyway , I have just measured my new acquisition : primaries are internal diameter of 36mm and 48 cm length while secondaries are 42 internal diameter and 60 cm length.
- my 4-2-1 small .jpg (40.19 KiB) Viewed 7913 times
I have ma de a calculation of capacity of both primaries and secondaries, Primaries have capacity of 488 cc and secondaries have capacity of 831 cc. The secondaries capacity is 70% larger than the capacity of the primaries.
Now, I have no knowledge of the gas flow theory , but remember Einstein saying that every good theory should also look elegant. The theory is not look elegant is inadvertently wrong. 70% increase of volume increase from primaries to secondaries does have a touch of elegance.
Not pretending that have the knowledge to make the judgment , it would be presumptuous to make such claim. Will it provide max performance of a highly tuned engine - no clue , but I would expect ( and hope) it to work nicely ...
What do you think of such proportions, Guy?
Miro
PS and how do you like the elegance test of a theory...?