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2.1l Ea82t


WJM
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So ive got a set of brand new never been used USDM STi EJ257 pistons.

 

Thinking...bore is 92mm on EA82x..and 99.5mm on EJ25x.....

 

I wonder if its feasibly possible to bore it out that far and remain mostly reliable...or better to sleeve it to 99.5....and then...I wish I were at home so I could measure things out...see if the heads would have a problem with the coolant passages.

 

Either way, by my calculations, it would be about 2080cc's with the STi EJ257 bore/pistons, and keeping the stock stroke.

 

I really dont think it would work w/out spending some serious $$$$ on sleeving...and I do have some extra blocks that I could try the boring on...but im open to all speculations on this. That means you too benebob. :-p

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Since the EJ series of engines use a larger wristpin you'll need to have some custom connecting rods machined too.

 

Also there's a good chance that you'll have some major cooling issues. By boring the cylinders out that much you may end up going it the water jackets and restrict how much water can flow through the engine after you put in new sleeves.

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Since the EJ series of engines use a larger wristpin you'll need to have some custom connecting rods machined too.

 

Also there's a good chance that you'll have some major cooling issues. By boring the cylinders out that much you may end up going it the water jackets and restrict how much water can flow through the engine after you put in new sleeves.

 

Oh crap...after looking at some stuff...and seeing the wrist pin stuff...scap yet another idea.

 

Anyone wany some STi pistons?

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To answer your question Erik, these are dry sleeve (also known as parent bore) engines.

 

All automotive engines, to the best of my knowledge, are dry sleeve. This is where the sleeve itself never touches the coolant, as the water is sealed in the block. The sleeve is also permanently (well, until it's machined out) in the block.

 

Wet sleeves are used in HD diesel engines. They can actually be removed from the engine block with a puller, and the coolant circulates around the sleeve in a cavity inside the block rather than through coolant passages in the block. These are especially advantageous because they can simply be replaced during a rebuild rather than performing extensive machine work on the block.

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To answer your question Erik, these are dry sleeve (also known as parent bore) engines.

 

All automotive engines, to the best of my knowledge, are dry sleeve. This is where the sleeve itself never touches the coolant, as the water is sealed in the block. The sleeve is also permanently (well, until it's machined out) in the block.

 

Wet sleeves are used in HD diesel engines. They can actually be removed from the engine block with a puller, and the coolant circulates around the sleeve in a cavity inside the block rather than through coolant passages in the block. These are especially advantageous because they can simply be replaced during a rebuild rather than performing extensive machine work on the block.

?? on honda motors the coolant is right outside the sleeves. the Coolant is all around the sleeves. but different manufacturers...

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... All automotive engines, to the best of my knowledge, are dry sleeve. This is where the sleeve itself never touches the coolant, as the water is sealed in the block. The sleeve is also permanently (well, until it's machined out) in the block...
My '58 Triumph was wet-sleeve. (Kind of cheating, though, since the engine was developed from a diesel engine.) You didn't need anything fancy to pull its sleeves; in fact you had to be careful when the head was off that you didn't turn the crank and unseat the sleeves. Made big bore kits easy; they just sold you new sleeves with the pistons.
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(shakes head side to side at the two of you 3 letter "ID's")

 

as for the bored out 2.1Litre idea.... aside from 'paperthin sleeves, i think one carry over from a previous thread(circa about 12-18 months ago atleast) i would also expect to convert the head bolts to head studs. right???

 

Oh and i would assume(uht ohh) that the piston head surface is suitable for valve travel in the EA series heads right?

 

And lastly... from this point i would for my curiousity sake ask what actual quantity of diameter is the difference between the pistons? in mm if you can swing it anyways... :rolleyes:

 

 

oh and BTW (points out window) I just saw a siloette cross over the moon in our totally clear sky... it was this most odd image of antlered herbivores and a sled with a chubby figure wriggling in it... you know I'd sware the lead animal had some odd light affixed to its nose.

 

anyone else see such a thing around midnight?

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I'm afraid the shape of the piston (ie: wristpin location) and overall height of the piston may be completely different. :( it would cost you as much to get new custom rods made as new pistons... so...

 

send your pistons out to a custom shop (paeco, ect.) and ask if they can make it at 99.5mm or (whathaveyou).

 

There are shops that will bore out, and resleeve a 4cyl engine for ~$900. one company I heard of does hondas for $900 and warranties them. by all means, if you can find a place that's noteable as far as quality of work and is less expensive, that's a no brainer.

 

so if you've got about $450+ for pistons and ~$900 for a warrantied resleeved bored out block, you could manage it I think.... but, remember that you're taking 3.75mm out of the block's wall thickness. so, you're going to want better cooling... maybe polishing the water ports/jackets wouldn't hurt. ;)

 

also, I would say those pistons would be cool, but I am paying off over $8000 in debt, so I think I need to get that done first.

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?? on honda motors the coolant is right outside the sleeves. the Coolant is all around the sleeves. but different manufacturers...

 

I thats called "open deck"....as there are several subie engines like that too. If you look closer...you will see the steel sleeve pressed into the water jackets.

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One guy I work with used to work in the pit, work on the motors, in some drag cars, ect. and says for optimum cooling, smoothing out the water jackets actually creates better flow. less friction inside means less percentage of the heat the water obsorbed resulting from friction, so more heat can be exhanged to the water as it passes in the ports from the warm block.

 

evidentally there's a process you can do to a block to acid dip the water jackets to get them to flow real well.

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One guy I work with used to work in the pit, work on the motors, in some drag cars, ect. and says for optimum cooling, smoothing out the water jackets actually creates better flow. less friction inside means less percentage of the heat the water obsorbed resulting from friction, so more heat can be exhanged to the water as it passes in the ports from the warm block.

 

evidentally there's a process you can do to a block to acid dip the water jackets to get them to flow real well.

(Optimum coolant flow)=(zero turbulence)=(boundary layer)= (no convection cooling)

 

I will point out that cooling really is not an important aspect of 1/4 mile racing. Its been a while since I paid much attention, but a few years ago the Top Fuel guys were going with solid blocks... no water cooling at all! A subie run long enough to stage and run a 1/4 mile probably wouldn't need water circulation at all.

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