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Originally Posted by hassmaschine
Now you're talking 
I'm not sure how the N52 cam is set up (it's really hard to tell based on BMW specs) but typically BMW uses a dual pattern intake/exhaust, where the exhaust has less duration and lift than the intake. That's fine for a stock engine, but when you mod stuff it doesn't work so well. I can definitely see a custom exhaust profile making a difference with MILVS and headers.. |
Quote:
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Originally Posted by Marty
When I look closely at the pictures,
In your thread 'cams' #2 post Pete has the cams backwards. What he called intake cam is actually the exhaust cam.
Everything I can find-
Intake cam- has 'shorter' base circle, 0.100" height or so, nearly the size of the cam bearing circle, WIDER lobes, shorter rear tip/end.
Exhaust cam- has TALLER base circle, 0.200", NARROWER lobes, longer rear tip.
The install pictures are correctly installed.
So what happened?
Pete got the cams reversed and Riot ground them wrong?
Or
Pete got them reversed and Riot ground them correctly.
I have a couple exhaust cams on heads. I'm thinking about sending them to Riot to get reground. If they tell me the specs great, if not I will just have them measured.
Intake cams with Valvetronic can NOT be reground, I've shown/proven that, but can be made to get more lift and slightly more duration, MILVs.
So MILVs + reground exhaust cam with more lift sounds like the way to go. And changing just the exhaust cam only is a much easier install and if careful and you mark the timing chain, timing will be good.
Just like changing the exhaust cam for leaking oil journals or whatever they call that.
N54 cams should fit and might fit the N52. Don't know the stock specs, but maybe use the Schrick 264* 11.0mm lift.
It looks like the only difference is the cams construction.
N52- hydroformed
N54- cast formed
They 'look' different.
So depending on cost, use-
-reground N52 exhaust cam, new core or used
-Schrick N54 264 11.0mm or 268 10.5mm. It looks like both are new cores and will work with stock valve springs.
Exhaust cam done, mike drop. Ha.
Intake cam done with MILVs.
Post it, think about it, see what hass thinks.
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So I'm posting - Early N52's did use a cast camshaft, but according to BMW, that didn't make a difference.