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Racer RX, future plans. No so secret mobile!
Posted 30 January 2004 - 10:23 AM
now if one jumps high enough,
they could say vis a vis.
But I'm too old for jumping.
If you care to see what I am rambling about try this link
Posted 30 January 2004 - 10:32 AM
Are valve heads also made with the denser process, or just made to fit the closed deck block?
I seem to recall seeing that grid on my EA81.
Posted 30 January 2004 - 11:11 AM
I have worked on many EA series engines and all of them have been closed deck.
Posted 30 January 2004 - 11:15 AM
Posted 30 January 2004 - 08:28 PM
Posted 31 January 2004 - 11:02 AM
Even the 'modern' EA71 1595cc OHV engine is CD.
Maybe unnecessary to explain, but: It is always possible to tell if a block is OD or CD when the heads have been removed.
Posted 31 January 2004 - 03:30 PM
Now what about the casting method for the EA engines?
Posted 01 February 2004 - 05:02 AM
1) A CD design will offer much stiffer cylinder bores, which allows you to run high(er) boost without blowing the head gasket.
2) Due to the casting process used for CD EJ-series engines, this will also increase the stiffness of the block when compared to OD designs.
3) A CD design is much more heat critical. Only if the entire thermal design of the engine and cooling system (both kinda doubtful on EA series engines when not new) is well designed this is not an issue (EJ series seem to do rather well).
4) OD engines (EJ-series) are lighter, have better cooling and are perfectly suited for normally aspirated applications. However, Subaru has managed to produce a wide range of reliable turbo engines based on this design, with engine output as high as 286 hp and engine torque of well over 250 lb-ft. However, these engines are not bulletproof.
5) The EA71, EA81(T) and EA82(T) all are CD designed and have proven to be bullet proof, as long as there's sufficient oil in the oil pan. Have you have seen one of these engines with the bearings gone? Thought so. Obviously, cooling is an issue. However, cracked heads have more to do with oil temperature than we think. In Europe, all EA82T cars run air-to-oil oil coolers, and never (even gen 1 MY85&86 engines) suffer cracked heads or gasket problems unless the radiator is gone. Not so for the European EA82 MPFi non-turbo engines, they crack them all the time. Only difference? Higher compression ratio and: NO OIL COOLER.
Oh well, so far this little write-up about our beloved engines.
Corky, can you find out what casting process has been used for EA-series engines? Rather interesting, I reckon.
Posted 01 February 2004 - 08:03 AM
Posted 01 February 2004 - 08:33 AM
GREAT info once again Marnix!
Posted 01 February 2004 - 09:45 PM
The OD/CD argument is completely a waste on time on any suby making less then 350hp. A OD EJ engine will run everyday 350hp for 100k miles any never have an issue. Just look at all the stage 3/4 wrx's. Do i think the CD EA engine will run 350hp for more then a week, NO WAY. There is soo much more in the engine design then the deck design that make it realible at high hp levels, and over the years subaru has fixed many of those issues. The EJ22T block can be a wicked engine with forged pistons and DOHC heads. Although if you run a high clamp pressure clutch you will kill the thrust bearing in no time. Just one of the many issues fixed in the phase II blocks.
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