I've been looking at engines for sale as an upgrade for my car and wondered how you would tell these two engines apart externally.

I know on the sti3 onwards the inlet manifold is red but that doesn't really mean anything.

Are there any identifying marks on the head/block or is the engine number unique to sti models?

Also is there any way of telling which model sti it came out of?

Thanks

 

anyone?

 

Dont the sti engines have the top painted in red ?

 

only from the sti3 on.....

externally there isnt much of a givaway ......was the turbo different from the wrx to the sti? and the intercoolers perhaps? a block will look like a block to me

 

I thought that was the case with the inlet manifold.

There is no inlet manifold, intercooler or turbo so it could be anything. I wondered if there were any markings that gave away what it is without opening it up

 

I think the red inlet manifold was from the version 2 onwards, they were the first cars to be produced by STI, not just modded after the production line.

My V.2 has a red inlet manifold.

 

That's all very well and good but the engine I'm looking at doesn't have an inlet manifold on it anyway. I'm sure that could be faked or changed if you wanted to pass a wrx engine off as a sti engine.

 

oi palmer stop modding ffs...stop it now

 

You can't have too many mods

 

The only real way to tell is to look at the heads on the engine, as the valve train is different to a wrx and each year sti has different cams.

 

i have a genuine UK short block spare if you want (pretty good shape )
only £2k and its yours, even throw in some oz wheels for yer

 

My block is already in better shape than that

It's mostly the valve train that I'm interested in but it seems I need the pistons to match

 

The turbos were always the IHI VF series AFAIK. i.e. not TD05 or TD04.

 

Dunno if this is any good

http://www.catherineandken.co.uk/sti/wrx.html

 

That's a really handy link thanks Are these markings on the block though is the next question?

 

Agree with Banny STI.

I think the only sure way is to whip a cam cover off. 10mm socket, 4 bolts, 1 min.

If the cams are actuating directly on buckets its an STI.

 

Does anyone have any photos of what it should look like?

Thanks

 

Yes.. but not in a head.. although should have my own back very soon..

http://www.jollygreenmonster.fotopic.net/p18419813.html

The shim is the small item like a watch battery.. it goes under the bucket..

WRX / UK heads have shims like 10p's and sit on top of the buckets.

If you remove the cam cover and look the cam lobe will hit the bucket rather than hitting a shim on top of the bucket..

Simon

 

So just out of interest, DO the STi's run hotter cams or is it just down to the differences in the tapepts? What are the fundamental differences between a classic STi head and a WRX head? I'd always thought that most of the STi's power was made by the ECU/turbo combo rather than any particular differences in the engine, barring the fact that some were blueprinted or closed deck, which surely would really only start to matter once you begin tuning it properly.

 

the cams are longer duration and higher lift..

I compared my STi3 cams with some UK98 cams

http://www.jollygreenmonster.fotopic.net/c683651_1.html

http://www.jollygreenmonster.fotopic...683651_13.html

Other differences are the shims being under bucket on the STi (less chance of the shim falling out) and the UK / WRX having over bucket.. so the rev limit can be higher on the STi heads. The valves are also different.. STi are sodium filled hollow and the WRX/UK solid.. the springs are also stronger on the STi again allowing higher rev limit as less chance of valve bounce.

Closed desk was not really an STi thing.. just some of the earlier cars had the closed deck block.. which was originally used on the Legacy.. perhaps just old stock used up on the Impreza before going with the open deck block?
But not STi specific. iirc

Simon

 

Thanks, all of this is confirming what I thought. I have sent an email to the seller asking them how they know that this is a genuine sti engine and I'll see what they come back with. Removing the cam covers is quite an easy way to tell it seems.

Thanks

 

get them to take a cam cover off and email you a picture.. then post it and we can tell if it is what they say it is.

 

dont sti engines generally have the fifth injector where as wrx engines do not? surely a simple way of seeing?

 

No that was an early RA thing and this engine as Paul has said already doesn't have a manifold fitted so how would you check.. lol

Simon

 

lol @ me, im thick when it comes to engines mate it was just an answer from my limited knowledge, in fact can you answer my post below this one?

 

I will do thanks. They are a good 200 miles away from me so I'd want it confirmed before I go up there to pick it up.

cheers

 

About the best i have Paul. The top pic if you look closely you can see the cam is acting directly on the bucket.

Combine it with the bottom pic, they use a small shim that sits under the bucket (not on top) so you will not see the shim if the engine is fully built.

Bucket is far right, shim is next to it.

http://img.photobucket.com/albums/v3...k/DSC00306.jpg

http://img.photobucket.com/albums/v3...k/DSC00300.jpg

 

That was the way that I was understanding it thanks That second photo is pretty clear too

Which version heads are they by the way? This engine that I'm looking at is a sti 2 one apparently.

Thanks

 

looks like STi3/4 to me..

STi2 may have over bucket shims.. but def not hydraulic..

 

Just been out to have a look at my spare ones Paul, they defo have little watch battery like shims under the buckets. I thought i had bought Rex, oh well i can live with that.....just need pistons now.

Great info lads