Hey guys, haven't been on here for a while, but I have some results of a head porting setup I've just completed setting up to a turbo setup.

Setup: All stock exhaust, headers, intake and etc.

Head Mods:

*1 mm undersized intake valves - to eliminate potential for valve tagging
*factory exhaust size
*High rigidity valve guides to maximize sealing and seating
*New valve seats
*dual valve springs
*Ti retainers
*stock seals and keepers
*Ports not enlarged, but port reworked, flow was maximized, no numbers on hand right now
*Compression lowered to 8.9:1 through combustion chamber reshaping

I know that the setup above sounds weird, especially with the undersized valve, but shouldn't be a big deal for turbo, valve sealing and valve sealing and rigidity was a big design consideration. Valve heat dissipation was also a big factor for longevity, as that is one of my big goals.

The results were pretty good for lower compression and all stock equipment:

Max Power:
Stock 192 HP Torque 129
Ported 204 HP Torque 134

The differential gain was across the entire band, the greatest area between the two torque curves are before VTEC under 6k, good area difference before VTEC too on HP, torque was flat after VTEC with a gain.

my goal was to lower compression and get the valve train reliable. The valve train has never sounded sweeter, even better than new. The engine song is a bit deeper too. I could just imagine this all motor, 11:1, headers intake and exhaust.

Seat of the pants is that it is faster, torq'ier, easier to throttle through 180's.

I'll post a dyno sheet when I can. What are your guy's thoughts?

Peter

 

Was the head flowbenched? Before and after flow numbers tell the big story.

Did you use stainless steel valves?

I'd like to see pictures of the combustion chamber. To get the compression down under 9:1 requires removal of considerable material and since the S2000 has very little excess, I am curious.


The smaller valves certainly would require flowbenching. I'm sure very few have gone this route with the S2000 and you are definately in uncharted territory. Put the turbo on and enjoy the power.

 

The tuner unshrouded the valves. This was a weird scenario, the core head was a bit warped, so quite a bit had to be milled off. So in conjunction with a thicker Cometic gasket and unshrouding the valves in the cyl chamber, 8.9:1 is what the calculations yielded. I silicone molded the chamber and calculated volume via specific gravity and cross referenced with water volume in a beaker, so I know that this is pretty accurate. It was also siliconed with the new valves in place.

 

Here's the valve train setup, double springs stainless steel valves, Ti retainers, minor porting.



Here's an exhaust valve, guides protrude quite a bit, won't hurt flow, but gives good valve sealing, especially at higher rpms, where it counts.



Intake side

 

check out the overall gain across the entire band with all stock setup and components, this is pretty usable power.

 

oops, open up on your browser and it'll resize to fit the screen.

dyno results

 

where did you get the Ti retainers ?

 

REV

 

While there are certainly gains to be had porting the head, the results seem a little weird unless I missed something.

The primary point of interest is that you gained more torque down low than up top. While there is a common misconception that porting doesn't help down low (it can and does), your reduction of compression by over 2 points would normally equate to a reduction in torque of 2-4% all other things being equal. Yet you gained over 10% torque in places on the bottom end. One usually doesn't see 15% gains in torque on the bottom end on a high efficiency engine just from porting.

Perhaps the smaller valves have something to do with it, or I'm misintepreting your modification description. I'd certainly like to hear more.

UL

 

Is this a web site?