** Rebuilding a Stroked/Turbo VT Ecotec **

[chargedvx6]

If you are blowing head gaskets on these things, nothing will save you. They should be run with MLS and I wouldn't consider anything less than the best for a good set up. Only as good as the next weakest link.

424rwhp, stock L67 bottom end, XPZ cam and alloy heads. 11.49seconds. YouTube - 11.49 ET @ 120 mph whippled v6

Not testamanet to the heads but no issues were experienced and the car was running nearly 18psi of Whippled 2.4L boost

 

[Tsunamix]

Ill say it again..... Theres stuff all to be gained from port matching the stock head. The Stock head has a port that is too large, as it was designed on an angle cut for an almost vertical plenum leg on the bunch of bananas stlye manifolds in the USA.

So the port is too big for the australian runner.

In the stock heads, quite a bit of gain can be achieved from cleaning up the back of the valve and bowl area though.

So if the alloy ehad already has that, for $1400 a set, well that sounds bloody interesting. especially as alloy conducts heat much better, and is not prone to cast irons thermal 'deposition' problems which can give localised hot spots.

Now if someone cumes up with an inlet trumpet manifold that has a runner thats relatively straight and around 20" long...well then we can match the trumpet to the port in the alloy head and give a slow concentric reduction in runner volume all the way from bell mouth to bowl. Perferct world....

 

[delcowizzid]

double that $1400 for a set LOL

 

[Adam_88]

Adam_88,

Keep me posted with any problems you have, and what youve done to make your build better Let me know how power figures go

ive already encounterd a few, how much boost are you planning on putting thru it, my bottom end is good for 30psi

 

[holden_4aw_lyfe]

im still going to port match the heads to the manifold, and the ports in the heads are a bit rough ill use the porting tool and fix them up a little bit but besides that they look amazing

Adam_88;

what problems? im planning on running around 20- 23psi safetly. My bottom end is good for 30-32psi aswell. Are you putting it together as we speak?

 

[Adam_88]

nah it's getting machined and concreted at the moment

 

[holden_4aw_lyfe]

what injectors you planning on running?

 

[klampy]

Ill say it again..... Theres stuff all to be gained from port matching the stock head. The Stock head has a port that is too large, as it was designed on an angle cut for an almost vertical plenum leg on the bunch of bananas stlye manifolds in the USA.

So the port is too big for the australian runner...

in my VR i actually opened up the heads to the same size as the gasket, and you are right, the opening in the head was HUUUUGE compared to the mani, so i went to town on the mani. opened it up all the way up the runner. i noticed a big lack of low down oomph, but above 3500 (where my cam was anyway)(and ill add, turbo cam/no overlap) crazy pickup all the way to a 6700 rev limit. and that was with a shitty HSV3800 tune and NO TURBO! there was no noticable flat spot until the rev limiter kicked in.

not fighting you, just adding my experience with porting and my result. =D

 

[Adam_88]

im not sure yet im gunna let my tuning bloke decide

 

[holden_4aw_lyfe]

yeah i think thats a good choice..went and saw my block, 3/4 of the way done. looks mint. Ill post pics soon!