OST-040: BOOOOSTed

[oldeskewltoy]

My new client is building himself a twincharged 4AGE. I believe it is going into an AW11. This client came my way, not by my many posts on here, or one of the many other forums, but through one of the machine shops I use. I'm also providing technical assistance to that shop with his block build (9.5:1 forged pistons). He is a "local" Portlandian.





As is usual the intakes are opened up, the short radius gets worked, and port to bowl alignment issues are corrected




The exhaust side gets opened up too. Since this head will be twincharged, the exhaust side is opened up a bit larger then is typical, a new SV3 exhaust gasket will be utilized.






more to come.......

[oldeskewltoy]

Progress...

in my post above - #4 is shaped and ready for finishing, and #3 is still rough..... while below is a 2 panel showing #3 is now shaped




and as fitted to the new gasket.... and now comparing shaped #3 to as yet untouched #2





more to come......

[oldeskewltoy]

Progress...


and as fitted to the new gasket.... and now comparing shaped #3 to as yet untouched #2





more to come......

​... and more progress





and more to come....

[Rogue-AE95]

Nice! Do you have a supply of those exhaust gaskets to sell to those who get a head ported? I saw that they have your OST moniker on the product.

[oldeskewltoy]

Nice! Do you have a supply of those exhaust gaskets to sell to those who get a head ported? I saw that they have your OST moniker on the product.

I had a hand in developing this gasket, but I'm not the seller - http://www.sv3power.com/store/index.php ... cts_id=217

The above gasket uses the same size opening as the blacktop gasket(35mm), but this gasket is slightly different that the port openings/holes are about 1mm taller, in relation to the bolt holes, to allowing for port work.

The stock 16V and Silvertop gaskets although large enough to fit most of my port work, are not properly aligned.....

[oldeskewltoy]

The intakes are all nearly finished....





and a bit closer on cylinders 2 and 3





more to come.....

[oldeskewltoy]

As "large" as those ports may look, they have actually "grown" only about 2mm in diameter.... they are still smaller then a stock Blacktop, but these ports flow more than a Blacktop's exhaust ports



With the exhausts now complete, its time.... the head goes into the machine shop tomorrow to receive its 3 angle and back cut.



more to come....

[Rogue-AE95]

Very nice. I will have to pick up one of those gaskets.

[oldeskewltoy]

The machine shop took nearly 3 weeks to perform the 3 angle, and back cut the intake valves....


but their 3 angle looks quite nice



The arrows are pointing to the seat/bowls that are not quite to size. Now that the valve job is done, the finishing touches are performed and now all the intake bowl/seats are @ 26.5mm, and all the exhaust bowl/seats are @ 22.0mm.....




Next... setting up the head for checking chamber volumes



and I've got one @ 37cc, and 3 @ 36.8cc...



I have a wee bit of work to do on chamber 1,3, and 4......


I'm holding off on the head cut, and final chamber volume until I know the actual deck height. The client purchased 9.5:1 pistons, and a .8mm gasket, AND wants me to keep static @ 9.5....



More to come.....

[oldeskewltoy]

I have a wee bit of work to do on chamber 1,3, and 4......

head is now machined.....



and the final chamber volume........ on near identical chambers





Assembly to come... then setting the clients cam-valve clearances....


More to come.....

[oldeskewltoy]

Assembly to come... then setting the clients cam-valve clearances....

Now assembled.....



all that is left to do... is set cam - valve clearances......



more to come.......

[oldeskewltoy]

all that is left to do... is set cam - valve clearances......

the cam sheet... with the the valve opening and closing events laid out....





9.4mm of lift is getting close to requiring clearancing the head so the lobes don't hit.... but not quite





setting clearances... spec is .20mm(.008") on the intake side, and .25mm(.010")... a thousandth is within tolerance.





Final questions: What is actual valve lift on exhaust valve #4?? And on #3 exhaust valve?



This head is now done, and will be heading back to it's owner shortly.....