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Discussion Starter · #1 ·
What's Fully Closed Deck and Semi Closed Deck?

Can EJ25 block be fitted without modification? Fit stock gear box? or should a beefier gear box be considered?

How much can the stock EJ20block handle?
 

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Here are some pics of a open, semi-closed, and closed deck ej20. Thanks to http://cobbtuning.com/ for the pics ;)

Each design has it's pros and cons.

A open deck block is the cheapest and easiest to manufacture, but it's also the weakest of the three.

A closed deck block is the most expensive and hardest to manufacture, but it's extremely durable.

A semi-closed deck block is a compromise of the two designs. It's stronger than a open deck block, yet cheaper and easier to manufacture then a closed deck block.



Open deck (standard ej20 block)
 

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Discussion Starter · #8 · (Edited)
okay now 2 different blocks, one open deck, one semi-closed.
given same bore and stroke/ compression ratio.

Would semi-closed make more power? or just strength in the block?

is there a 2.5L closed deck out there? 2.4L semi closed?

what other players are out there besides STi and Cobb? I know JUN has pistons and cranks... Who else produce blocks?

more torque the better~!

I need about a $18000 loan...
 

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okay now 2 different blocks, one open deck, one semi-closed.
given same bore and stroke/ compression ratio.

Would semi-closed make more power? or just strength in the block?
Yes and no. All things being equal, the engines would produce the same power. However, the added strength of a semi-closed or closed block would allow you to reliability produce more power, via more boost, higher rpm limit, or higher CR.


is there a 2.5L closed deck out there? 2.4L semi closed?
Sorry, I should have been more specific about the Cobb blocks in my above post. The Cobb semi-closed block is 2.2L and the closed block is 2.5L. Too bad they're so darn expensive :(
 
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