Cam Lobes

[longassname]

Originally Posted by SVXRide

2) the special sauce also provides an increase over the 257 deg, 8.75mm lift intake cam approach - with additional margin on coil bind (i.e., ss has slightly less lift ). Looking at +10Hp at 5, 6, and 7k rpms. Folks would have to decide for themselves if they're willing to trade the reduced margin on coil bind and the 10Hp for the lower cost of just replacing the intake cams.

-Bill
p.s. Michael - the valve springs (inner/outer) showed up yesterday (Thursday)

I'm not sure I'm following what you are saying. In #2 you are comparing the special sauce intake and exhaust cams to the intake cam I gave the specs on without an exhaust cam?

[SVXRide]

Originally Posted by longassname

I'm not sure I'm following what you are saying. In #2 you are comparing the special sauce intake and exhaust cams to the intake cam I gave the specs on without an exhaust cam?

I'm comparing their projected performance to that of an EG33 equipped with a 257 deg, 8.75mm lift intake cam and a stock EG33 exhaust cam (performance curves posted a couple of posts back in this thread)
-Bill

[longassname]

Ok, I think my mind just has problems even considering replacing only the intake cam as an option.

Originally Posted by SVXRide

I'm comparing their projected performance to that of an EG33 equipped with a 257 deg, 8.75mm lift intake cam and a stock EG33 exhaust cam (performance curves posted a couple of posts back in this thread)
-Bill

[SVXRide]

Originally Posted by longassname

Ok, I think my mind just has problems even considering replacing only the intake cam as an option.

agreed
-Bill

[longassname]

Ok, good, have fun.

Originally Posted by SVXRide

p.s. Michael - the valve springs (inner/outer) showed up yesterday (Thursday)

[benebob]

Originally Posted by SVXRide

hey, I'm going to be a threat as long as I can keep the car straight

Have you and Dave joined the DC region of SCCA so you can come down in run in all of our ProSolos in 2007?

-Bill

Why would you need to join a region where you carry your driving shoes to the event. As I stated before I'd like to not autox much at all this year if we can swing it. Still need to get that engine to our builder.

[SVXRide]

Originally Posted by benebob

Why would you need to join a region where you carry your driving shoes to the event. As I stated before I'd like to not autox much at all this year if we can swing it. Still need to get that engine to our builder.

Now I know why I'm not doing as well as I thought I should be doing...I'm wearing my driving shoes to events
-Bill

[oab_au]

Originally Posted by longassname

that looks a lot like my recomended intake cam used for both intake and exhaust

Yes amazing isn't it. Yours are the same as I suggested back here.
http://www.subaru-svx.net/forum/show...2&postcount=44

Harvey.

[SVXRide]

Originally Posted by oab_au

Yes amazing isn't it. Yours are the same as I suggested back here.
http://www.subaru-svx.net/forum/show...2&postcount=44

Harvey.

just call me the persistent searcher
-Bill
p.s. Harvey - did you get my last PM re: any shifting in lobe centers?

[longassname]

Are those the cam specs he's looking at now? There's a big difference between that cam and the profile I suggested. The seat to seat is the same but that's a much slower ramp and shorter 50 thousands duration.

Originally Posted by oab_au

Yes amazing isn't it. Yours are the same as I suggested back here.
http://www.subaru-svx.net/forum/show...2&postcount=44

Harvey.

[SVXRide]

Originally Posted by longassname

Are those the cam specs he's looking at now? There's a big difference between that cam and the profile I suggested. The seat to seat is the same but that's a much slower ramp and shorter 50 thousands duration.

Michael,
They're not the same...close, but not the same...the profile you suggested is more aggressive and has more lift. The SS cams are geared to NA, AT SVXi.
-Bill
p.s. think you might be able to tune to the 550 cc injectors?
p.p.s. the 370cc injectors have suddenly turned to gold on Ebay

[longassname]

When you are running the sims and looking at your theoretical outputs are you taking into account the hydraulic lash adjusters? I was taking your 8.75mm to be an optimistic measured lift esitmate based on the 8.9mm lift on the lobe I suggested.

I know you are trying to stick with the stock valves and springs so I understand going with a lower lift; actually if you apply all the usual standards to the measurements you took of the stock intake valve set up you shouldn't go above 8.32mm but you will probably be ok with what you are thinking. I'm curious to see how those springs I sent you set up on the stock valves and what the coilbind height is with them.


The 370's are the cheap ones--that's mainly why they were chosen, asside from being very good. You should be able to get them for $70 for a set of 4 pretty easily.

Originally Posted by SVXRide

Michael,
They're not the same...close, but not the same...the profile you suggested is more aggressive and has more lift. The SS cams are geared to NA, AT SVXi.
-Bill
p.s. think you might be able to tune to the 550 cc injectors?
p.p.s. the 370cc injectors have suddenly turned to gold on Ebay

[longassname]

What's the installed height of the factory outer spring?

[SVXRide]

Well, I finally got over to my machinist's shop and took some measurements with the inner/outer spring set up LAN (Michael) sent me. The outer spring is definitely stronger, as the wire diameter is .150 inch vs the stock outer spring's .125 inch. While stronger, this also plays out as a spring that reaches "coil bind" earlier, to the tune of 0.055 inches earlier (Stock spring set has a fully compressed height of 0.715 inch, while LAN's spring's compressed height is 0.770). Given the fixed distance that the spring retainer is at, relative to the spring pad in the head, this results in a reduction of 0.055 inch (=1.397mm) in all of the measurements I took earlier in this thread (post #16). This means, using LAN's new springs, that you have the following "lift to bind" measurements (specific to the one head I've used):

Exhaust valves:

8.9662 mm
8.9916 mm
9.1186 mm
9.3472 mm

Intake valve:
8.509 mm

-Bill

[longassname]

Did you install the spring and measure the free travel or just fully compress the outer spring and subtrace the difference from your previous coilbind height measurements? I believe it is the inner spring which binds first isn't it.