I am about to rebuild my 2.5 and currently it has a set of heads and Cams from a 98 Type-R Fitted, these heads were ported by RCMS a few years ago.

the Engine will have Billet Crank, Wiseco Pistons, Brian Crower Rods, ACL Race Bearings, Cosworth Baffle Plate, Cosworth Oil Pump and 14mm head stud conversion. Cometic Gaskets.

I have a Spare set of 2002 WRX heads, and can source a WR1 inlet if needed, I am also aware that i would need to change the Injectors to side feed, but i will be doing that any way regardless which route i go.

Turbo choice has not been decided yet, but i will probably run the engine in on the TD06 20G

I plan on fitting Stage 3 cams, Supertech Double valve Springs and the Titanium Retainers, and all valves will be replaced too.

My Goal is 550+ so want to ensure i get the heads and cams right 1st time.


Thanks
Derek

 

avcs seems the way to go

 

If you go avcs, Lateral cams are an excellent option

 

when u say AVCS heads, i assume u mean fit AVCS Heads with the NON AVCS Cams?

If not then I guess my current Simtec will need to be replaced?

 

You have going for a dog bollocks build, go the whole hog and get a syvecs ecu to control the avcs heads with avcs cams

 

simtek can control the avcs, needs to go back for a mod tho

 

Does not have active knock control though

 

I have been happy with the Simtek, but the Knock control is a Concern.

I plan to run 20% meth. I have not looked at the Syvecs, guess i need to look it up.

 

it will tho...................someday

 

Thats what I used to think and gave up after 2 years

 

I found these on Ebay, but they have cracking around the spark plug hole, is this an Issue?

http://cgi.ebay.co.uk/Subaru-STI-EJ2...item3a62ea0cca

 

Sorry to butt in matrix but your type r heads, were they machined matched to the 2.5 block? if so do you have any pics of the chambers as i'm doing a build but would like to see what machining needs doing?
Thanks.

 

They are still on the Engine in the Car at present.

When i got the Heads they Came from Tiley Of Bristol of their 2.0 Race Car.

I used the 2.5 Head Gasket and I scribed the underside of the head, to mark the combustion Chamber, and then used grinding stones on the end of the drill, and then the Dremil. after i was happy, i then used the Dremil to polish the Combustion chamber up. as i had the heads on my 2.0 to start with i had them lightly skimmed and Vaccume tested.

I had no issues with the heads after doing this.

 

Thats a shame as i have v4 sti heads off my type r and cant find any pics anywhere of them machined to match and dont want to start doing it until i've seen one already done
Thanks.

 

Generally not an issue and can be repaired, however the guy has them listed on snet for £400....

 

Thanks Banny, I will do a search for his post.

 

Just out of interest can you run the AVCS heads as in the ebay ad but without using the AVCS.

By that I mean can you use these heads with a version 4 simtek?

Also would there be any gains over standard v4 sti heads?

 

Yes you can disable the avcs and run without, did this with a version 5 sti running a power fc.

Main benefits of avcs are better spool and more torque, however the RCM car runs version 3 head castings as does Madhammer and both cars are over 700bhp.

 

Don't let it concern you m8, you have a good mapper

Martyn