Engine Covers - 3.0

A

AlanZ

New member
Hi,

New to the forum and on the look out for a Z4 coupe 3.0 is Sport. Apologies if this has been asked before but I have been looking at some photos of coupes for sale, some have a silver engine cover and some have a black engine cover. Are these the same engine specs on the 3.0? (2006 had a silver cover and 2007 had a black cover)?

Thanks Alan
 
AlanZ said:
Hi,

New to the forum and on the look out for a Z4 coupe 3.0 is Sport. Apologies if this has been asked before but I have been looking at some photos of coupes for sale, some have a silver engine cover and some have a black engine cover. Are these the same engine specs on the 3.0? (2006 had a silver cover and 2007 had a black cover)?

Thanks Alan
Click to expand...

Hi the later 3.0si cars had the black top engine with a few updated parts, they produce the same power as the silver top cars. The ccv was altered and it also gained a plastic cam cover instead of the earlier metal version. Water pumps were a later variant which seems to last longer, valve stem thickness was slightly reduced as well but no one seems to know what that’s achieved. :thumbsup:
Rob
 
The change seems to have occurred around September 2006 as my Coupe built in August 2006 had the earlier silver cover but my October 2006 one had the black cover.

I know there were quite a few technical changes, but as has been said the power output was the same and I couldn't feel any difference in how they drove.

If you want to see what the exact differences are the earlier silver cover ones are an N52 and the later black cover ones are an N52k. Here's a link to an earlier thread:- https://z4-forum.com/forum/viewtopic.php?f=2&t=105709&start=45
 
Z4C_er said:
I'd say the valve stem reduction is to help with unsprung weight and inertia.
Click to expand...

Erm, valve springs are by there nature “sprung” nothings been changed by any reduction in inertia as power/rev limits are unchanged.
Unsprung weight is a term normally used for items connected to the cars suspension, not engine components :?
Rob
 
Narrower valve stems provide a larger opening for the same size hole in the cylinder head.
 
Smartbear said:
Z4C_er said:
I'd say the valve stem reduction is to help with unsprung weight and inertia.
Click to expand...

Erm, valve springs are by there nature “sprung” nothings been changed by any reduction in inertia as power/rev limits are unchanged.
Unsprung weight is a term normally used for items connected to the cars suspension, not engine components :?
Rob
Click to expand...

I think you know what I meant, but OK, wrong terminology. I meant that having the valves lighter means they can move easier and with reduced inertia.
 
Z4C_er said:
Smartbear said:
Z4C_er said:
I'd say the valve stem reduction is to help with unsprung weight and inertia.
Click to expand...

Erm, valve springs are by there nature “sprung” nothings been changed by any reduction in inertia as power/rev limits are unchanged.
Unsprung weight is a term normally used for items connected to the cars suspension, not engine components :?
Rob
Click to expand...

I think you know what I meant, but OK, wrong terminology. I meant that having the valves lighter means they can move easier and with reduced inertia.
Click to expand...

That’s true but instead of bringing improvements to engine performance which those changes usually lead to there was no change at all :o
Rob
 
I think you will find subtle differences in the power curve between an N52 and an N52K, despite the peak figures being similar.
 
ph001 said:
I think you will find subtle differences in the power curve between an N52 and an N52K, despite the peak figures being similar.
Click to expand...

I didn’t think they were similar, they’re identical aren’t they? Have you got a link for the different power curves, I’ve not seen any mention of this by bmw? :?
Rob
 
I have a N52 training manual that shows the changes brought about by the N52. If anyone would like it, let me know.
For example, there were power output changes:
N52.JPG
 
Z4C_er said:
I have a N52 training manual that shows the changes brought about by the N52. If anyone would like it, let me know.
For example, there were power output changes:
N52.JPG
Click to expand...

I have that information also, but it doesn’t relate to the black top n52 & was describing the silver top earlier version relative to the m54, I’d like to see something official describing different outputs of the early & late n52 :?
Rob
 
Smartbear said:
Z4C_er said:
I have a N52 training manual that shows the changes brought about by the N52. If anyone would like it, let me know.
For example, there were power output changes:
N52.JPG
Click to expand...

I have that information also, but it doesn’t relate to the black top n52 & was describing the silver top earlier version relative to the m54, I’d like to see something official describing different outputs of the early & late n52 :?
Rob
Click to expand...
OK
 
My 2006 3.0 si has the black valve cover.
 

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Sorry for digging up the thread, but...

I'm in a market for a 3.0si. I know about the engine upgrade in Sep 2006, I know what exactly has changed, but what I don't know is this - is one better than the other? Should I limit myself to only the updated engine? 3/4 of the cars on the market seem to be silver tops.
 
There were quite a few updates on the N52K (black top) but I certainly wouldn't be limiting myself to it if the rest of the car was the spec you were looking for.

Summary of updates all in this thread here.... https://z4-forum.com/forum/viewtopic.php?f=2&t=105709&hilit=n52k&start=45
 
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