[calisti]

Got my BC 272 cams and Supertech dual valve spring kit. I was thinking of just replacing the exhaust valves with inconel Supertech valves and using the stock intake valves. I'll replace the intake valves if I can sell some of my parts though.

[calisti]

Well I'm going to order the Supertech black nitride intake valves and the inconel exhaust valves. Should I stay standard size or go 1mm larger? No port and polish and will going 1mm shift me to the right more? Will there be a noticeable difference with going 1mm larger?

[calisti]

I just picked up my block today after a 3 wk wait. I had John Edwards talk to CP Piston's tech support to get the right ra numbers for their rings. Cosworth's tech support also recommended an ra of between 20 or lower for the deck surface to have their head gasket seal correctly. So this was the goal when resurfacing the top of the block deck. John also checked the mains for straightness. The crank was sent out to have a .001" clearance on the rod journals. He also balanced the whole rotational assembly to 0.5 gram.

Here's some vids of machinist I used, John Edwards from Costa Mesa R & D:

Honing an STI block
YouTube - Subaru STi Block Honing

Here's another vid from John Edwards of R & D Costa Mesa resurfacing a Subaru SVX block with sleeves:
YouTube - Subaru SVX Sleeved Block Resurfacing

Here's another of his custom 6 qt Subaru oil pan:
YouTube - Subaru Aluminum Oil Pan, etc...

[gabedude]

Originally Posted by calisti

Mike, CP tech support gave me ring gap numbers: top ring .025, 2nd .028, oiling ring .15, and also recommended due to the hardness of the 1st ring the cylinders must have a rough hone. I had my machinist call Mike to get the proper ra (roughness average) numbers and what grit honing stones are required.

That's what I gapped mine to (I was worried that it was too large of a gap) and after removing one head (I installed a comp ring upside down and it was smoking, had to fix that) and re-installing a new ring set on the piston, I noticed the walls with my rough hone were nice and smooth (the rings seated pretty quickly) and the car no longer burned oil. I have ~250 miles on the motor (plus a bunch of idling and revving) and it has a tad bit of slap when cold, but goes away once warmed up. Seems like it is going to be fine. These are ceramic coated CP dropins.

[viperguy]

Originally Posted by calisti

Now I'm contemplating on going with the ATP gt35r instead of AVO's ts gt3076r.

Stick with the TS buddy..

Any idea on the cost of your motor?

[calisti]

Originally Posted by viperguy

Stick with the TS buddy..

Any idea on the cost of your motor?

Once the motor's done I just slap the vf36 back on until AVO comes out with their ts. They came out with a new exhaust housing cast and was sent to the machine shop. Hopefully it'll be out soon. I believe it's already up towards $6500 usd and I don't have everything I want. I'm just trying to spend on parts that wouldn't require pulling the motor again.

[BM_STi]

those videos are awesome! I think I just found my new engine builder.

[calisti]

Originally Posted by BM_STi

those videos are awesome! I think I just found my new engine builder.

He's highly recommended. John has taught this field for 10 yrs, published a book called the "auto dictionary", and has several other publications.

My mechanic broke the plastic cam gear exhaust sproket on the passenger side even with the right tools. Can that be replaced with a metal gear off of another 2.5 na subie motor?

[viperguy]

I'm going to sit back and watch.. Mine is due a rebuild.

[gabedude]

Originally Posted by calisti

He's highly recommended. John has taught this field for 10 yrs, published a book called the "auto dictionary", and has several other publications.

My mechanic broke the plastic cam gear exhaust sproket on the passenger side even with the right tools. Can that be replaced with a metal gear off of another 2.5 na subie motor?

I wouldn't do it, even if it fit.

[calisti]

If the gear teeth line up and are the same size diameter, why not?

[gabedude]

If they are near the same weight, then it shouldn't be a problem. I doubt it would make a difference either way though.

I never would use the subaru cam locking tool to break the TQ on the cam bolts. Use an old timing belt.

[calisti]

Finally all the parts for the heads are in. Heads and parts will be taken to Portflow for valve job and assembly.
Supertech std size black nitride intake valve and std size inconel exhaust valves


Supertech dual 70lb springs, ti retainers, alloy seats, Brian crower avcs 272 intake and exhaust cams

[gabedude]

Pretty!

[calisti]

Talked to Tom at Portflow this morning and said there was some core shift in the casting that caused the valve seat to overhang over the cast inlet ports. So I went down there and took some pics:

Sorry text is to small. It says this is a pic from under the valve seat that shows the lip where the seat overhangs over the casted port and would disrupt airflow as air flows up between the valve and the seat.

See the shadow on the right side under the seat. Well that's how much it overhangs over the port.

The mark in the middle of the angle of the valve shows where it seals against the seat right now. They're going to move the 45 angle more to the edge then it transition into a radius. So by doing this there was no need for larger valves.

So Tom said what they have to do is bore out the throat on the valve seat then hand port the bowl. So there really was no need for larger valves. Plus he told me larger valves usually brings the edge of the valve too close to the edge of the combustion chamber which would then require opening up the combustion chamber.