Racer RX, future plans. No so secret mobile!

[Skip]

I was too lazy to do a simple Google. The answer is given here and from the look of this evan a carbed EA82 block is closed. The grid work has nothing to do with it being closed/ open, it appears it may have been an indicator of the casting process NOT the internal consturction,

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

http://www.legacycentral.org/library/deck.htm

[beauregaardhooligan]

It would seem that weighing the block would be a better indicator.

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.

[Dr. RX]

Guys, I'm not sure that you can compare the casting methods of the EJ series engines with the EA series engines. That's like comparing oranges and tangerines, both citrus, but have many different characteristics. Marnix was talking about EJ series engines and I don't think he intended to implie that the same held true for the EA series engines.

 

I have worked on many EA series engines and all of them have been closed deck.

[Skip]

Imagine that, Corky is too old (or wise or both) for jumpin' to

[WJM]

Well, I wonder what it (the grid pattern) is for the EA engines...for the EJs it means closed deck. Does it also mean the med. cast method? For the EJ22G, it means med cast AND closed deck. But the EAs....we know its closed deck. Its definatly NOT open deck. Can see that with the eyes. But med cast...how do we tell?

[Marnix]

However, I've read somewhere that early EA-series engine (60s and 70s) had issues with failing head gaskets due to vibriation of cylinder linings... That could mean that Subaru then switched to the more expensive CD block design.

 

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.

 

:brolleye:

[WJM]

OK....I gathered as much.

 

Now what about the casting method for the EA engines?

[Marnix]

Obviously, we are talking about two different issues here, but both related to one subject, namely block stiffness.

 

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.

[LegacyT]

hmmm very interesting info. I had no idea the EA82/T's were closed deck. And the info about fitting an oil cooler is also good to know in the future.

 

Thanks,

Mark

[WJM]

Ive got 4 oil cooler adapters for the EA82T....for sale.

 

GREAT info once again Marnix!

[scoobie steve]

Marnix, The EJ207 was used from MY99 on.

 

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.