I started to pull apart one of my engines the other day because it used to nock a bit when cold and i thought it would be better to do this sooner rather than later just in case i could reuse the crank.
I got the pistons out but they look a bit different to the ones in my other engine . I can see the engine has been apart before because it has all been sealed up with clear silicone and i can see where they have pryed the block halves apart with screwdrivers .
Are these standard pistons?
the engine came out of a 1993wrx





Also the gudgen pins have a much thicker wall the hole in the middle is only about 7mm

 

They are New Age WRX HBR Twin Dot pistons (cast not forged) and not suitable for a MY93 WRX because of the Compression Height.
The block they came out of should be a rear thrust type.

Version 1 ~ 4 Block with smooth casting inside water pump housing




Version 5 onwards with extra cooling ribs inside water pump housing




Mick

 

Hi, sorry to jump in, but Mick, is there any way to tell what pistons are in an engine without pulling it apart? Maybe taking a plug out and using a borescope to see?
Only reason i ask is my cars an import, and it seems to me to have been modded, then returned to standard again(ally rad, ecu wiring spliced, triple layer head gaskets etc), so wondered if it was standard inside?

Thanks, Mit

 

its definitely a center thrust block

 

Its been put together at some time with the wrong pistons mate.

Mick

 

Mit - yes, you can use a borescope to check out the ID markings on the crowns of the pistons if they are not too carboned up and remove a gudgeon pin access plug to check the under crown markings.
You can also check out the valve codes on the heads if you have a 180 degree adaptor on the bore scope.

Mick

 

what a total pain in the *** more expense

 

there used in 97 wrx's.

i was taking one apart the other day. they had the same pistons in

 

OLD THREAD REVIVAL!!

Well i took the heads of mine the other day (Engine came out of a 1995 wrx)

Pistons that are stamped HBR!!. . So much be out of a block from a newage wrx??..Am i right

Also the rods...Will these have to be out of a newage wrx due to the compression ratio?

Any of the number's markings on the block able to date the block to newage or classic?

Regards

Tom

 

All the rods are the same length (apart from the N/A one's) 130.50mm so can be reused again - just the compression height of the pistons which differ.
Rear thrust blocks will have 6 bolt bellhousing(plus the 2 studs at the bottom) whereas the Center thrust block has 4 bolt bellhousing plus the 2 studs.

Mick