[tetsuo111]

You were one of the people I had hoped would reply....

Looks like Axiom launched a thread about these last year:

http://www.e90post.com/forums/showthread.php?t=1021012

Sadly, there was no confirmation that they exist. These Schrick cams are like the N52 version of 'Nessie'. Infrequent sightings, never confirmed.

The cams (if they exist) are the easy part. I'm not aware of a tune with updated VANOS maps to implement - hint hint....

[tetsuo111]

FYI - Have been in contact with a German vendor of the Schrick cams. They use software from DTE-Systems to support the cam upgrade.

Have no plans to pursue further until I wrap-up multiple unfinished projects.

[Taskmaster]

This thread makes me sad.

[justpete]

Originally Posted by TheAxiom

This thread makes me sad.

Yeah, me too... :/

[Taskmaster]

In light of the fact the cams can be retarded by 10 degrees, are these salvageable Hass?

[hassmaschine]

I don't think so - I think they ground the exhaust cam thinking it was the intake, and vice versa. There's really no way to know what Pete actually has.

[Taskmaster]

Originally Posted by hassmaschine

I don't think so - I think they ground the exhaust cam thinking it was the intake, and vice versa. There's really no way to know what Pete actually has.

You're not even my real dad Hass, don't tell me what to do!

[justpete]

Originally Posted by TheAxiom

You're not even my real dad Hass, don't tell me what to do!

lol

Only thing to do with those stupid fuckin cams is make lamps out of 'em...

[Mike.]

Originally Posted by justpete

lol

Only thing to do with those stupid fuckin cams is make lamps out of 'em...

Hahahaha!!! Loling out loud at the restaurant

[CobraMarty]

JustPete-

Way early you measured the stock intake cam- nose 1.427" and base 1.182"

Did you measure your reground intake cam, nose and base?

Advancing the intake cam generally will give less hp and more tq. (corrected)

If the cams were ground at the same duration and advance/intake, it looks like you wanted and they have about 10.5-10.6mm valve lift. If the 'safe' goal is 10.5mm valve lift, maybe using the stock cam and increasing the rocker ratio would achieve the same results. This seems to be what Schrick also grinds the intake valve lift to, 10.6mm.

Stock cam lift is about 6mm (0.245") and valve lift is 9.7mm which is 1.6166:1 rocker ratio.

These numbers are close to actual numbers but the actual numbers could be slightly more or less. Like stock rocker ratio 1.55:1 to 1.65:1 with 1.6:1 being an average value.

Anyway to gain 0.8mm more valve lift with the stock cam would require an increase in rocker ratio to about 1.73:1.
Maybe that's how to get that additional 0.8mm of valve lift (without having to grind the cams 4* advance) and more power.

Now that your cams are a 'fail', can you say what the specs are that Riot gave you?

[Taskmaster]

Originally Posted by CobraMarty

JustPete-

Way early you measured the stock intake cam- nose 1.427" and base 1.182"

Did you measure your reground intake cam, nose and base?

Advancing the intake cam generally will give more hp and less tq and hp usually at a slightly higher rpm.

If the cams were ground at the same duration and advance/intake, it looks like you wanted and they have about 10.5-10.6mm valve lift. If the 'safe' goal is 10.5mm valve lift, maybe using the stock cam and increasing the rocker ratio would achieve the same results. This seems to be what Schrick also grinds the intake valve lift to, 10.6mm.

Stock cam lift is about 6mm (0.245") and valve lift is 9.7mm which is 1.6166:1 rocker ratio.

These numbers are close to actual numbers but the actual numbers could be slightly more or less. Like stock rocker ratio 1.55:1 to 1.65:1 with 1.6:1 being an average value.

Anyway to gain 0.8mm more valve lift with the stock cam would require an increase in rocker ratio to about 1.73:1.
Maybe that's how to get that additional 0.8mm of valve lift (without having to grind the cams 4* advance) and more power.

Now that your cams are a 'fail', can you say what the specs are that Riot gave you?

Well, you would want cam retard for additional HP, advance would increase low end power generally. There is also the issue that modifying the rocker ratio could effect low lift drive-ability.

[CobraMarty]

Thanks, that is what I meant, correction made.

I'm not quite sure how the increased rocker ratio would effect the low lift drive-ability. It would just be like you gave it a little more pedal.
Maybe at idle it would cause a slightly higher idle rpm due to the slightly increased lift but I am sure that the DME would adjust and back down the eccentric cam to lower the idle speed.

[hassmaschine]

I think you would get faults without extensive reprogramming.

[justpete]

Originally Posted by CobraMarty

JustPete-

Way early you measured the stock intake cam- nose 1.427" and base 1.182"

Did you measure your reground intake cam, nose and base?

Advancing the intake cam generally will give less hp and more tq. (corrected)

If the cams were ground at the same duration and advance/intake, it looks like you wanted and they have about 10.5-10.6mm valve lift. If the 'safe' goal is 10.5mm valve lift, maybe using the stock cam and increasing the rocker ratio would achieve the same results. This seems to be what Schrick also grinds the intake valve lift to, 10.6mm.

Stock cam lift is about 6mm (0.245") and valve lift is 9.7mm which is 1.6166:1 rocker ratio.

These numbers are close to actual numbers but the actual numbers could be slightly more or less. Like stock rocker ratio 1.55:1 to 1.65:1 with 1.6:1 being an average value.

Anyway to gain 0.8mm more valve lift with the stock cam would require an increase in rocker ratio to about 1.73:1.
Maybe that's how to get that additional 0.8mm of valve lift (without having to grind the cams 4* advance) and more power.

Now that your cams are a 'fail', can you say what the specs are that Riot gave you?

Didn't measure the regrind cams, no point in that. Advancing the cam in this engine will result in a loss of power as VANOS won't correlate with the actual cam position. There should be no offset. There can be a mechanical retarding offset at installation but it won't work either without a lot of work in the DME maps. And you can't change the rocker ratio. Lift isn't as important as duration, overlap, and max retarding angle so it's a fool's errand unless you want to get rid of Valvetronic and machine the head to use an N54 cam tray, custom "std" cam, and N54 cam chain, etc. The regrinds were ground with an advance because either VANOS wasn't known or wasn't understood as I didn't request it.

[CobraMarty]

I've had other cams reground on stock cores as there were no other cores available and to get more duration they had to also advance the cam to get the extra duration. If just wanted more lift, they could have kept the regrind straight up. You have to move it advanced as you can only go where there is material to grind. That is why the cam got reground 4* advanced.

Maybe you can change the rocker ratio. Parts are being machined now. An engine is on a stand now waiting to check and test. Just saying...

[Taskmaster]

hassmaschine Maybe they needed a Degree wheel to put them in, because if waht Cobra said was right - the increase in duration came at a cost of adding in built in advancement.

[hassmaschine]

Possibly, but it also depends on the shape of the lobe. The N52 intake lobes are pretty much symmetrical so that doesn't really make sense to me.

The N52 doesn't need more cam advance, it's not even using all that it can do (except one cell in the part-load maps). But it could use an extra 10 degrees of intake cam retard, similar to the S54 which maxes out at 130 degrees (vs 120 on the N52).

[justpete]

Originally Posted by CobraMarty

I've had other cams reground on stock cores as there were no other cores available and to get more duration they had to also advance the cam to get the extra duration. If just wanted more lift, they could have kept the regrind straight up. You have to move it advanced as you can only go where there is material to grind. That is why the cam got reground 4* advanced.

Maybe you can change the rocker ratio. Parts are being machined now. An engine is on a stand now waiting to check and test. Just saying...

Um, no. He ground in an advance purely in an attempt to increase low end torque. Wasn't necessary to increase duration.

Good luck with inceasing rocker ratio. Pointless exercise but good luck anyway.

[hassmaschine]

yeah, that would make sense in the context of an engine with fixed cam timing - but not with VANOS.

[CobraMarty]

Originally Posted by justpete

Um, no. He ground in an advance purely in an attempt to increase low end torque. Wasn't necessary to increase duration.

Good luck with inceasing rocker ratio. Pointless exercise but good luck anyway.

But if you don't want to increase duration, increasing lift will help to make more power.

[justpete]

Originally Posted by CobraMarty

But if you don't want to increase duration, increasing lift will help to make more power.

Why wouldn't I want to increase duration, that's what I originally said was more important than lift.

[CobraMarty]

Originally Posted by justpete

Why wouldn't I want to increase duration, that's what I originally said was more important than lift.

I guess it depends on what you want. More duration, more lift, more duration and lift, more peak hp, or more power across the whole rpm range.

I would rather have 5-7 more hp across the whole rpm range than 10-12 more peak hp at 300 higher rpm than stock.

Usually increasing duration moves the power curve and peaks further up in the rpm range. And increase in hp at higher rpm is usually at the expense of tq at the lower rpm.