Work in progress [540i 4.9 Kompressor buildstory] - Page 83

Fart · 9th November 2010, 17:18

Quote:

Originally Posted by mattmartindrift

I've seen numerous failures (mostly annoying oil seapage) after cometic installs on freshly machined engines - my [Nissan] race engine being one of them. I reverted to an OEM gasket w/ ARP head studs and voila! Plus, I like using OEM gaskets - if things go bad they act as the weak link...instead of the con rods or other expensive bits.

100% agreed.

My cometic did still provide the weak link, it blew between cyl 1-2 and 2-3 on my M3. I decided to go with OEM HG and upgraded the ARP's from normal to 2000.

T-TRIM 540i · 9th November 2010, 18:14

Quote:

Originally Posted by mattmartindrift

I've seen numerous failures (mostly annoying oil seapage) after cometic installs on freshly machined engines - my [Nissan] race engine being one of them. I reverted to an OEM gasket w/ ARP head studs and voila! Plus, I like using OEM gaskets - if things go bad they act as the weak link...instead of the con rods or other expensive bits.

That is all I have at the moment is a little seepage , but I am going to pull it apart before it is a major problem.The Raceware head studs are the only ones I know of unless I get custom ones made for the car.....

E38 Prototype · 9th November 2010, 18:23

T-Trim, Do you happen to know what the Surface RA was of the block and head after machining? I ask because in my turbo world it needs to be as smooth as possible, with the stock headgaskets (our 4.4l are metal correct?) To get a perfect seal under boost.

Also, The normal ARP's tend to not hold as well and we use A1 head studs.

Just a couple notes from the turbo import world

T-TRIM 540i · 9th November 2010, 18:53

Quote:

Originally Posted by E38 Prototype

T-Trim, Do you happen to know what the Surface RA was of the block and head after machining? I ask because in my turbo world it needs to be as smooth as possible, with the stock headgaskets (our 4.4l are metal correct?) To get a perfect seal under boost.

Also, The normal ARP's tend to not hold as well and we use A1 head studs.

Just a couple notes from the turbo import world

I have no clue what the RA value was when VAC put the motor together.
Yes the BMW OEM head gaskets are metal.
I have a call into Paul at VAC to find out a few facts ,he has been real good at helping if I talk to him directly.
My bore is 94mm so I am sure I have the S62 gaskets in there,maybe,not sure ,that is why I have a call into Paul...I emailed Tony,but that can take awhile....

E38 Prototype · 9th November 2010, 19:02

The lower the RA number, the better. For a metal head gasket you want the finish to be near polished. Failures are usually always due to the surface being damaged, or not being smooth enough.

I know you like to read up on things so here is a good article, if you scroll down a little.

[BlindHandyMan] Interesting article for you highly trained Mechanics and

T-TRIM 540i · 9th November 2010, 19:07

Quote:

Originally Posted by E38 Prototype

The lower the RA number, the better. For a metal head gasket you want the finish to be near polished. Failures are usually always due to the surface being damaged, or not being smooth enough.

I know you like to read up on things so here is a good article, if you scroll down a little.

[BlindHandyMan] Interesting article for you highly trained Mechanics and

Cool ,I will read...Chris at VAC just called and said they have the proper gaskets that are not S62,but yet 94mm bore and are BMW OEM so I guess I will have them send them to me....

Fart · 10th November 2010, 09:26

Quote:

Originally Posted by T-TRIM 540i

Cool ,I will read...Chris at VAC just called and said they have the proper gaskets that are not S62,but yet 94mm bore and are BMW OEM so I guess I will have them send them to me....

Are you sure the OEM S62 gaskets are metal???