Cam Question

[Mike-TurboE24]

Is there any benefit to using the stock cam in my 1986 635CSi vs. a cam from a 745?

I'm running a Callaway turbo set-up.

Thanks fellas.

[Monotalonawd]

Not sure about the one from a 745i but, I've read here that some guys use the cam from the M30 3.3l on the 3.5l 'cause it has a more aggressive profile.

[Bill in MN]

You're going to lose low end grunt with a more aggressive profile. I'm running a 265 in the S2.

[russc]

right,
weve discussed this alot. The 3.3l cam is a 272-274. You loose ~10% torque in the mid, gain 10% hp on the top end. Id make that trade any day. The power delivery is one I like alot as the engine dosen't laydown at 4800rpm. The power delivery is more like a ///M5.

From what I know, the M106 cam is no upgrade, in any sense. It's not different enough from the stock M30 to be of any use.

RussC

[QUOTE="Monotalonawd"]Not sure about the one from a 745i but, I've read here that some guys use the cam from the M30 3.3l on the 3.5l 'cause it has a more aggressive profile. [/QUOTE]



[Edit by russc on [TIME]1132648060[/TIME]]

[gol10dr1]

i will be using the b33 cam when i crack the head open for some mods towards the summer time.

[Andy335Touring]

Does no one make a turbo grind cam for the M30 ?

[gol10dr1]

well metric mechanic made a cam for NA m30's but it turned out that it also worked very well with the FI m30's. i know bmw335ist (jason) had one before his horrible accident.

[Jesse]

I'm running an M106 cam right now. Why?? I don't know other than when I was putting my regular M30 head back together with all new stuff this last time I had one laying around the shop (motronic one) and though I could tell no difference what so ever between it and my original euro L-Jet one or a regular US3.5L one, I used it anyway just because. I had to put the converter nut on the end of it to run it with my old L-Jet controls (for the old-school distributor drive).

I imagine a higher lift cam like a Schrick(?) would allow more air to be forced in with a turbo engine too, but I'm not sure how it would run in general. Ha sanyone done that? I've profiled my rocker arms to recieve a cam like that but do not have one to try yet. ~_~

[russc]

right, his car made lots of power also.

RussC

[QUOTE="gol10dr1"]well metric mechanic made a cam for NA m30's but it turned out that it also worked very well with the FI m30's. i know bmw335ist (jason) had one before his horrible accident.[/QUOTE]

[russc]

the Schricks are too much overlap for street use, but can work. If you need to pass a smog test, forget it, ovelap is way to high in a FI car. You'll burn up cats fast when under acceleration, as lot of overlap dumps unburnt fuel in the exhaust.

If you can get a low duration(~274 or less) with more lift in a Schrick, that would be good.

RussC

[QUOTE="Jesse "]I'm running an M106 cam right now. Why?? I don't know other than when I was putting my regular M30 head back together with all new stuff this last time I had one laying around the shop (motronic one) and though I could tell no difference what so ever between it and my original euro L-Jet one or a regular US3.5L one, I used it anyway just because. I had to put the converter nut on the end of it to run it with my old L-Jet controls (for the old-school distributor drive).

I imagine a higher lift cam like a Schrick(?) would allow more air to be forced in with a turbo engine too, but I'm not sure how it would run in general. Ha sanyone done that? I've profiled my rocker arms to recieve a cam like that but do not have one to try yet. ~_~ [/QUOTE]

[Velocewest]

[QUOTE="russc"]the Schricks are too much overlap for street use, but can work. If you need to pass a smog test, forget it, ovelap is way to high in a FI car. You'll burn up cats fast when under acceleration, as lot of overlap dumps unburnt fuel in the exhaust.

If you can get a low duration(~274 or less) with more lift in a Schrick, that would be good.

RussC[/QUOTE]

"FI" = "Forced Induction" or "Fuel Injected"? I have a Schrick 282 in my NA motronic engine, and it passes smog no problem with the stock chip, and the catcon is 3 or 4 years old and healthy. Is the problem in a boosted engine that the combustion is incomplete due to the boost forcing the mix out during overlap?

[russc]

[QUOTE="russc"]the Schricks are too much overlap for street use, but can work. If you need to pass a smog test, forget it, ovelap is way to high in a FI car. You'll burn up cats fast when under acceleration, as lot of overlap dumps unburnt fuel in the exhaust.

If you can get a low duration(~274 or less) with more lift in a Schrick, that would be good.

RussC[/QUOTE]

[QUOTE="Velocewest"]"FI" = "Forced Induction" or "Fuel Injected"? I have a Schrick 282 in my NA motronic engine, and it passes smog no problem with the stock chip, and the catcon is 3 or 4 years old and healthy. Is the problem in a boosted engine that the combustion is incomplete due to the boost forcing the mix out during overlap?[/QUOTE]

Well,
I guess I need to be more clear. Yes, FI as in Forced, sorry. Thats usally the nomenclature here. But I see the confusion. With the smog test, it can vary by state also. CA were Im at can be a bitch to pass even w/o the high duration CAM. Other states are easier. You may be in one of them. It can help alot if you can tune the car as I do for the different configurations.

RussC

[Tjn182]

I don't have exhaust inspections - so would the schrick be beneficial at all? What kind of improvements would we see.... would they be drastic?

[russc]

Just like any high duration cam, you loose low end torque, gain high end power. Economy would suck. If you run a cat, it will burn out fast with a turbo and high duration cam. The gains to me would not be drastic over a 274 cam. Say another 10%. Since no one here has ever used one, know one knows for sure. We know about the stock b34, b35, b33 and MM turbo grind.

RussC

[QUOTE="Tjn182"]I don't have exhaust inspections - so would the schrick be beneficial at all? What kind of improvements would we see.... would they be drastic?[/QUOTE]