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Discussion Starter #1 (Edited)
I am in the market for a good / as new / reconditioned cylinder head for my 3.6ltr S38 engine.

Not desperate just yet, and will consider either a bare cylinder head, or complete with valves.

There must be some height left in the depth guides -- not like mine that has been machined / skimmed a few times and now has reached the limit of 'facing'.

Anyone out there able to help?

Also, is the 3.8ltr cylinder head interchangable onto the 3.6ltr engine?
What are the differences?

I know the part numbers are different, and possibly the valves and chambers slightly larger (or not), but is it possible to use a 3.8 cylinder head on a 3.6?

Share your knowledge please.

cheers !! :confused2 :confused2

UltimateM
 

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Hi.

How I know...

On a 3.8 engine the head is modified around the ignition spark wilder the water "space"(a little cooling inprovement), the valaves is bigger around 1.5-2 mm, and the inlet side of the head is bigger. And the cam is on 3.8 is 264 degre (pluss 8-10 degree compare with the 3.6 head.)

Frank


UltimateM said:
I am in the market for a good / as new / reconditioned cylinder head for my 3.6ltr S38 engine.

Not desperate just yet, and will consider either a bare cylinder head, or complete with valves.

There must be some height left in the depth guides -- not like mine that has been machined / skimmed a few times and now has reached the limit of 'facing'.

Anyone out there able to help?

Also, is the 3.8ltr cylinder head interchangable onto the 3.6ltr engine?
What are the differences?

I know the part numbers are different, and possibly the valves and chambers slightly larger (or not), but is it possible to use a 3.8 cylinder head on a 3.6?

Share your knowledge please.

cheers !! :confused2 :confused2

UltimateM
 

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Discussion Starter #5
Thank you for the 3 different replies:

Frank, will the 3.8 head bolt on to the 3.6 engine and work? The larger valves would be a performance plus, however the cam profiles are dependant on what cams I install. The question still remains though, will the 3.8 head just 'bolt on' and go.

Paul, I have visited the infinicar site and saw the 3.8 head which is very tempting, however I need to wait for confirmation -- or not-- as to if it will just bolt on with no complications or modifications.

Greg, I have visited the link you supplied and sent an email to the seller. Just waiting for a response to see what happens next.

cheers all

Malcolm
 

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One problem I would envisage would be decreased compression ratio due to (presumably) larger combustion chambers in the head due to the larger capacity of the 3.8 engine.

I'm not familiar with the S38 engine yet, maybe someone can confirm if the compression is acheived on the 3.6/3.8 engines with a bowl in the piston, a chamber in the head or combination of both?

I'd guess at the very least you will probably have to get a re-map done to take account of the difference in valve size.
 

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UM, try this link - http://bmwe34m5.com/faqs/?theme=1&level=3&chapitre_id_select=38&document_id_select=3
this will give you some info on the differences between the b36 & b38 i.e. increased bore / stroke / compression ratio plus a move to individual ignition coils. My thinking is that the 3.8 head will fit ok, but how well it would work is a different matter - the lack of a distributor is an obvious problem for starters.
Cheers,
Phil.
 

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Discussion Starter #8
Phlem5 said:
UM, try this link - http://bmwe34m5.com/faqs/?theme=1&level=3&chapitre_id_select=38&document_id_select=3
this will give you some info on the differences between the b36 & b38 i.e. increased bore / stroke / compression ratio plus a move to individual ignition coils. My thinking is that the 3.8 head will fit ok, but how well it would work is a different matter - the lack of a distributor is an obvious problem for starters.
Cheers,
Phil.
Cheers Phil,

I have already been to that site and got the impression that the heads will bolt on without problems (in just bolting ON).

The obvious problem is 'no distributor', so I may need to explore the ignition spark area more thoroughly before proceeding. I dont think compression will be an issue, as the 3.8 ltr was achieved by increasing both Bore & Stroke.

Interesting feature is the re-engineering to allow for more cooling.......very useful for the extreme hot climate regions of the world.

Hopefully someone out there has either managed a conversion or has both heads on a bench and can compare / advise me and other members of the differences amd any major hurdles that may --or may not be there.

Lucky I am not desperate for a resolve.....................not yet anyway.

cheers !!
 
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