Subaru Impreza EJ20 EJ25 CYLINDER HEAD STAGE 1

These heads have all the bells and whistles done to the valvetrain and is a great upgrade for someone using a stock/oem shortblock or a mildly prepped shortblock all the way to a forged short block. This head package is designed to bolt on with no special service required for installation that is different then a stock head. We first start with a oem/stock core pair of heads either your core or one of ours we always hold in stock.  If its your core and its damaged but repairable then our engineers will assess the heads and inform you of the extra charge for repairing it IF its repairable. 

And only then perform upgrades and all the parts from there. The heads are torn down and all stock parts removed, then it and its oem parts are bathed in an acid solution to remove all dirt, oil and residue that is left behind so that you essentially have a new pair of cores.

The surface is then checked for straightness and skimmed accordingly. Usually no more then 2 thousandths’ is taken off so a stock head gasket or aftermarket head gasket of your choice can be used without worrying about failing at a later stage. Then the stage 1 head package build begins.  We start with a thorough port and polish to the whole cylinder head.  Then we use all the original cylinder head parts ready for modification to suit the stage 1 head. Valves, springs, spring seats, valve guides, collets and will also recieve BRAND NEW valve stem seals etc etc. 

All the valves get machined angled valve jobs in addition to the FULLl port and polish cylinder head. No matter what stage cylinderhead we build they ALL go through the same strict checks as our short blocks do such as crack and pressure tests and sonically checked to ensure the heads are going to be reliable to use once installed. ALL our Stage 1 cylinder heads use their oem components and factory parts. If any parts are found to be damaged or out of tollerance then they are replaced with new oem parts.  We check all valve guides to be up to spec, any that are not are replaced with new ones, the valves are machine cut and matched to each individual seat that they are to be mated to.

This price also includes shimming to suit your camshafts, so you will need to send in your camshafts to us for us to to be able to do this as part of the service on this head package. If your purchasing new camshafts from us then there will be no need for you to do this and we can also offer better prices on parts and service on this head.

This head is good enough to flow up to 500whp reliably.

For an optional extra charge of £180 vat we can offer stiffer valve springs and titanium retainers which will allow this head to rev to 8500rpm reliabily with any camshaft profile up to 272 degree. Without the uprated valve springs and retainers your rev limit will be restricted to Around 7200rpm to maintain reliabilty from valve float issues.

*** This price does not include an exchange for your old cylinder heads that is presumed not to be damaged. If you cannot provide a pair of cylinder heads with it's original cam caps and full valve train or if it is to be found beyond use or not re-usable then there will be a £250 additional surcharge to this order. Once YOUR head has been given the "OK" we will refund your £250 innitial deposit *** If you have any questions related to this prodcut/service then please contact us via email or telephone to discuss them.