Reshard1977

iTrader: (17)

Hi All,

I'm just trying to get my head round a few things for a long term project.

I bought my 2003 WRX PPP with a knocking bottom end, and swapped the long engine for another EJ20 engine, which works fine now.

I've ended up with a spare EJ20 engine thats knocking, it wasnt knocking badly, and i dont know the exact reason why it started knocking.

Would it be OK to use the knocking engine to convert to a 2.1 stroker?

If it would be OK, what would be needed to convert it? I've seen kits that contain the pistons and little else for about £500, would that be enough to convert it?

I'm not after big power, i'm after low down power/torque with 300-340bhp

I'm sure it would be cheaper to just buy a V7 or 8 sti engine, but i'm more interested in a long term project, collecting bits as they come up (after all, thats where the fun is!) and ending up with a 2.1 engine.

As always, cheers in advance for everyone's opinions and sharing of knowledge!

the shreksta

iTrader: (20)

I am doing the same and I will buying all my stuff from the states as it's alot cheaper.you will need more than 500 quid mate,you need a 2.5 crank,rods,pistons,bearings,seal kit,head gaskets,head studs,oil pump,timing kit

What heads are you planning on running?

the shreksta

iTrader: (20)

Plus you will need your old block checking for size

Type_R_1984

It's the 2.5 crank that makes it a stroker.

Reshard1977

iTrader: (17)

Hi Matt,

its strange how they can sell the "2.1 stoker kit" with what looks like just the pistons?

I havent got as far as thinking of heads, i'm just trying to figure out what parts are needed for the initial conversation. Its a long term project. But now i'm wondering if it would be cheaper to get a kit? But, that wouldnt be as much fun obviously :-) My scooby is up and running, so i'm not in a rush.

So your project's back on then? I met Duncan shortly after i got the ecu, told him that someone smashed into you and could be a write off, he was gutted for you.

Reshard1977

iTrader: (17)

Hello mate, thats exactly what i was wondering about. Cheers for clearing that up!

So, technically, if you just swapped the crank it would be a stroker 2.1? I know it probably makes sense to refresh everything while the engines apart, but just trying to understand it all.

Cheers again

KAS35RSTI

iTrader: (73)

Your block may need the rear thrust converted depending on which block it is.

ditchmyster

iTrader: (7)

Read and ingest the op dude.

It's a 2003 wrx so no conversion required.

KAS35RSTI

iTrader: (73)

Doh!

In that case you wont need a centre to rear thrust conversion

Type_R_1984

Yeah technically if you just change the crank to a 2.5 one then it will be a 2.1.

Type_R_1984

Although saying that I think the reason they sell 2.1 pistons which are the same size as 2.0 is because they may have a different compression ratio for the extra throw in the crank but I'm not 100% on this.

AS Performance

iTrader: (4)

std 2.0 rods/pistons will not work with a 2.5 crank or else you would have around 100:1 compression..........

crank, rods and pistons need to be "matched" to make a 2.1

i do know of at least one company suggesting you can bore a std 2.0 block massively to make a 2.1 but i would not recomend it

jura11

iTrader: (7)

As above Resh

2.1L making stroker pistons,rods and much importantly EJ257 crank

Yes you can re-use yours WRX block if its knocking,you can buy parts easily for rebuild like ACL bearings,rods/pistons stroker combo,OE Gaskets/seals,Headgasket and ARP headstuds etc

You can go route re-using yours EJ207/205 crank and go with 2.2L stroker(I think this kit making Cosworth and few others),main difference is as above EJ207/205 crank and longer rods,pistons

Jura

ScoobP1

iTrader: (1)

You need these parts.

https://www.scoobynet.com/subaru-par...ged-parts.html

Reshard1977

iTrader: (17)

Thanks everyone!!! Have all the information i need for now! I'm going to aim for a 2.1 project to be completed for mid/late next year.

First step is to get my WRX block stripped and checked.

This is exactly why i'm so proud to be a scoobynet member.

Cheers all! :-)

jura11

iTrader: (7)

Hi Resh

Have look on those two stroker kits

http://www.advancedautomotives.com/b...vcs-1407-p.asp

http://www.advancedautomotives.com/s...age-1484-p.asp

Those rods we run at 490bhp without the issue on the Open Deck Block and 11mm ARP headstuds,Cosworth Headgasket Kit and Cosworth pistons etc

Jura