Closed deck blocks
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Scooby Regular
Joined: Nov 1999
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Or try this,
"The early turbo motors have a closed deck block. Up to 1995 they were build
for the World Rally Champioship and were expected to see 400+hp fro just two
liters. Pure racing engines. The open deck N/A motors have open spaces
between the cylinders and the edge of the block that comprises the mating
surface between the block and the cylinder head. The early turbo motors have
a flat-machined mating surface with the cylinders and several water and oil
passage holes visible on a deck of solid aluminum. The early turbo block is
much stronger and more stable for this reason. It is designed to withstand
the thermal stresses of turbocharging and stay together atmuch higher
specific outputs than the N/A motors. The coolant circulation in the upper
block and head region is particularly improved.
In 1996 the WRX turbo motors were revised to use an open deck configuration.
There were two reasons for this change. The rally car rules were changed to
restrict the intake to 32mm, limiting horsepower to about 300 at 6000 rpm.
Second, there were several advances in coatings and thermak control of the
upper cylinder area, giving much better stability of the gasket surface. The
cost of sand casting thousands of closed deck blocks is much more than their
die cast open deck cousins the change was made.
Aside from lower compression pistons and oil spray piston cooling, the
cylinder heads are also of slightly different design. The intake manifold,
exhaust manifold, cooling system, and sensor technology are all of different
design. Different still from the WRX engine, the WRX-RA engine uses a
hardened crankshaft and sand-cast, larger water-jacketed heads. It is
interesting to note that the RA motors still share connecting rods with the
N/A 1800cc motor. The quality is in the N/A motors, it is just put to
different use. The 2.0, closed deck, 1995 WRX-RA short block is still the
drug of choice in Japan for the "Big Power" motor."
I think that about sums it up, eh?
Nito
"The early turbo motors have a closed deck block. Up to 1995 they were build
for the World Rally Champioship and were expected to see 400+hp fro just two
liters. Pure racing engines. The open deck N/A motors have open spaces
between the cylinders and the edge of the block that comprises the mating
surface between the block and the cylinder head. The early turbo motors have
a flat-machined mating surface with the cylinders and several water and oil
passage holes visible on a deck of solid aluminum. The early turbo block is
much stronger and more stable for this reason. It is designed to withstand
the thermal stresses of turbocharging and stay together atmuch higher
specific outputs than the N/A motors. The coolant circulation in the upper
block and head region is particularly improved.
In 1996 the WRX turbo motors were revised to use an open deck configuration.
There were two reasons for this change. The rally car rules were changed to
restrict the intake to 32mm, limiting horsepower to about 300 at 6000 rpm.
Second, there were several advances in coatings and thermak control of the
upper cylinder area, giving much better stability of the gasket surface. The
cost of sand casting thousands of closed deck blocks is much more than their
die cast open deck cousins the change was made.
Aside from lower compression pistons and oil spray piston cooling, the
cylinder heads are also of slightly different design. The intake manifold,
exhaust manifold, cooling system, and sensor technology are all of different
design. Different still from the WRX engine, the WRX-RA engine uses a
hardened crankshaft and sand-cast, larger water-jacketed heads. It is
interesting to note that the RA motors still share connecting rods with the
N/A 1800cc motor. The quality is in the N/A motors, it is just put to
different use. The 2.0, closed deck, 1995 WRX-RA short block is still the
drug of choice in Japan for the "Big Power" motor."
I think that about sums it up, eh?
Nito
Scooby Regular
Joined: Jan 1999
Posts: 716
Likes: 0
never mind the wrx - that was NOT the topic of this thread..
the sti engine is closed-deck - as are all high revving (8200 rpm not 7000)variants of the ej20 - why is it we have to have all these 'armchair expert' responses on the bbs ? - suffice it to say that I do own an sti5 and I do know its spec.
as for web links with this info...
its a shame the sti website changed when they introduced the v-limited as it was in the spec list with a picture - the s-201 website mentions the fact and so does the subaru cyprus web site (which was translated from the original sti 5 web pages )
can we close this debate now? - thanks,
Paul W
the sti engine is closed-deck - as are all high revving (8200 rpm not 7000)variants of the ej20 - why is it we have to have all these 'armchair expert' responses on the bbs ? - suffice it to say that I do own an sti5 and I do know its spec.
as for web links with this info...
its a shame the sti website changed when they introduced the v-limited as it was in the spec list with a picture - the s-201 website mentions the fact and so does the subaru cyprus web site (which was translated from the original sti 5 web pages )
can we close this debate now? - thanks,
Paul W
Scooby Regular
Joined: Dec 1999
Posts: 267
Likes: 0
Paul W.
I've come to the conclusion by reading your replys to this and other threads that you're a bit of an **deleted!!**. The replys in this thread I think have been very helpful and interesting (apart from your efforts). The only reason you've got the hump is that someone dared to say "an sti5 has an open deck block". Tisk tisk, how dare they. Close this debate immediately.
. You didn't start this thread so you've no right to try and close it!
[This message has been edited by Steve Howat (edited 07-07-2000).]
Ok, I've calmed down a bit now (bad week you know
) Besides Pauls dad's probably bigger than my dad, lol.
Anyhow, posts like Pauls are the exact reason I don't read this BBS very often anymore, least of all the general section. I am however interested in this topic regardless of whether its an STi, WRX or type UK.
Ta
a 'mellower' Steve.
[This message has been edited by Steve Howat (edited 07-07-2000).]
I've come to the conclusion by reading your replys to this and other threads that you're a bit of an **deleted!!**. The replys in this thread I think have been very helpful and interesting (apart from your efforts). The only reason you've got the hump is that someone dared to say "an sti5 has an open deck block". Tisk tisk, how dare they. Close this debate immediately.
. You didn't start this thread so you've no right to try and close it! [This message has been edited by Steve Howat (edited 07-07-2000).]
Ok, I've calmed down a bit now (bad week you know
) Besides Pauls dad's probably bigger than my dad, lol.Anyhow, posts like Pauls are the exact reason I don't read this BBS very often anymore, least of all the general section. I am however interested in this topic regardless of whether its an STi, WRX or type UK.
Ta
a 'mellower' Steve.
[This message has been edited by Steve Howat (edited 07-07-2000).]
Scooby Senior
Joined: Jun 1999
Posts: 3,410
Likes: 0
paul w,
From what I recall, the closed deck block is an extra cost option on most of the recent cars. If this is the case, then you may well have a closed-deck block... or not.
Once the homologation rules of group A were dropped in favour of the WRC rules, it makes sense that subaru would look to cut costs and use more easily constructed open-deck blocks on later cars where they have also scaled the turbocharger down in the pursuit of a more responsive road car. I can't remember hearing of any block failures on a scooby yet, open or closed deck.
Have you had the heads off your engine block yet, that's the only real way to be 100% sure about this... after all, who says the specs you are quoting are 100% correct?
Nito,
Good post!
Moray (Armchair sceptic)
From what I recall, the closed deck block is an extra cost option on most of the recent cars. If this is the case, then you may well have a closed-deck block... or not.
Once the homologation rules of group A were dropped in favour of the WRC rules, it makes sense that subaru would look to cut costs and use more easily constructed open-deck blocks on later cars where they have also scaled the turbocharger down in the pursuit of a more responsive road car. I can't remember hearing of any block failures on a scooby yet, open or closed deck.
Have you had the heads off your engine block yet, that's the only real way to be 100% sure about this... after all, who says the specs you are quoting are 100% correct?
Nito,
Good post!
Moray (Armchair sceptic)
Scooby Regular
Joined: Apr 1999
Posts: 4,410
Likes: 1
My old My97 had what must be termed a "variable deck". Whenever there was a cassete in the player the "deck" was closed and hey presto operating the Eject button resulted in an "open deck".
Hope this clears this debate up
p.s. not quite sure how a multichanger effects the equation
Hope this clears this debate up
p.s. not quite sure how a multichanger effects the equation
Thread Starter
Scooby Regular
Joined: Jun 1999
Posts: 770
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Er, thanks for the replies, but, any ideas where to get one from, nless anyone cone prove that STi Vs had them as std. Which they don't - I think. 
Or, if not, is a tandard block good for a 2.2 stroker kit, hybrid, ECU upgrade (with extra boost obviously) - will it stand 360ish hp?
Assuming I might want to do it Bye Stef 
Or, if not, is a tandard block good for a 2.2 stroker kit, hybrid, ECU upgrade (with extra boost obviously
) - will it stand 360ish hp? Assuming I might want to do it
Bye Stef
Scooby Regular
Joined: Jan 1999
Posts: 716
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hmmm - 900 odd quid - presumably you could then use the one you already have as a base for a coffee table - should make an interesting conversation piece - especially when you say you ordered it on the advice of scoobynet bbs posters - ho ho.
paul w - (just off to tell a porsche 911 owner he actually has a V8 diesel engine)
paul w - (just off to tell a porsche 911 owner he actually has a V8 diesel engine)
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