911 heads

Frallan · Post by **Frallan** » Sun Dec 09, 2007 6:19 pm

All the posts were there a few weeks ago. As for links, all worked except the one for Bobtail/Russ which I have not tried.
When I have more time I will compile it and test it on this page.
If needed, I will add more pictures.

Post by **Piledriver** » Tue Dec 11, 2007 6:05 pm

What happens to old Boxter motors?

Frallan · Post by **Frallan** » Tue Dec 11, 2007 11:32 pm

Piledriver, "talk out of your beard" as we say in Sweden. Can not hear you clearly.......
VW boxer or do you refer to Porsceh Boxsters or something else?
Was it meat to get us thinking? :-)

Post by **Piledriver** » Wed Dec 12, 2007 1:24 am

Thought is they have blown motor issues, but you would need a 3.4 for the bore size.

Might pick up cheap, might be close enough to make viable bits on a T4, just saw off a cylinder/little welding

Water cooled DOHC 16v heads... Yum.

Might be interesting, don't have the familiarity to say, but Jake might, as well as others. They don't fall out of trees here, but I'm perhaps not in the right circles, so to speak.

(Just poking the beehive)

M-Owen · Post by **M-Owen** » Wed Dec 12, 2007 4:33 pm

I cut up a head from a 996 recently and I am convinced that with some welding, machine work that could indeed work. I think if you used Aluminum cylinders and welded them to the head like Porsche did with their early watercooled GT-2 engines ( I think they used a type of welding called Electron beam welding). If I can get thru my current project with out pulling any hair out...it might be worth trying.

Post by **Piledriver** » Wed Dec 12, 2007 7:46 pm

M-Owen wrote:I cut up a head from a 996 recently and I am convinced that with some welding, machine work that could indeed work. I think if you used Aluminum cylinders and welded them to the head like Porsche did with their early watercooled GT-2 engines ( I think they used a type of welding called Electron beam welding). If I can get thru my current project with out pulling any hair out...it might be worth trying.

Cool.

I strongly suspect there are aluminum brazing techniques that would be ~ as strong as 356 aluminum would be EB welded, and might allow rework assuming a re-heat treat was performed. I'm thinking finned jugs ans WC heads.

Brazing also allows parts with somewhat different expansion rates to play nice.

EBW is Expensive.

Unkl Ian · Post by **Unkl Ian** » Wed Dec 12, 2007 8:55 pm

Why do you need to weld barrels onto heads ?

Post by **Piledriver** » Wed Dec 12, 2007 9:41 pm

Unkl Ian wrote:Why do you need to weld barrels onto heads ?

Ian, you of ALL people should understand why !!!

... Same reason Porsche electron beam welded jugs on their high boost racing engines...
...No head gasket...
No head gasket to leak.

T4/98x66... water cooled 16V OHC... one piece cylinder/jugs...good T1 Hbeams... How much boost/RPM could it take? (hey, might work for the LSR project you were looking at)

Frallan · Post by **Frallan** » Thu Dec 13, 2007 2:37 am

That WAS clear and nice.
I love those ideas.
Some similarity to my old rough SC TIV engine with watercooled heads and aircooled aluminium cylinders. In fact it was 98 bore and 82 stroke.
That is an idea to consider. I am in Miami today with my old dragracer and friend who is a car auction buyer&dealer. We are to attend an auction this morning, now I have a good idea to look out for a blown Boxter.
Very inspirational.
I still have the old Oettinger /Mahle alumnium nicasil cylinders lying around. Needs new plating and custom pistons but why not?
I see a hybrid water/air cooled 98x66 with a whipple on top of it....:-)

M-Owen · Post by **M-Owen** » Thu Dec 13, 2007 10:22 am

You might find that early 996 heads are easier to find than Boxter heads. The 996 was prone to cylinder failure in it's early life. I found a set on EBay that were loaded with cams and all.

I would stick with EB welding simply because it's more precise and does not leave much warpage. This is the type of welding I used when putting my experimental cam towers together. This way crazy amounts of boost could be seen with out leakage. Some of the brazing might work but I question it's overall stability But then again in my line of work we usually come up with an idea and others implement them so I could be wrong...who knows

Unkl Ian · Post by **Unkl Ian** » Thu Dec 13, 2007 12:48 pm

The 3 main crank will become a problem sooner or later.

The Bonneville idea has been delayed;at least.

Probably for the best.

Piledriver wrote:
Ian, you of ALL people should understand why !!!
... Same reason Porsche electron beam welded jugs on their high boost racing engines...
...No head gasket...
No head gasket to leak.

T4/98x66... water cooled 16V OHC... one piece cylinder/jugs...good T1 Hbeams... How much boost/RPM could it take? (hey, might work for the LSR project you were looking at)

M-Owen · Post by **M-Owen** » Fri Dec 14, 2007 8:40 pm

Hey can someone tell me why it's not a good idea to have my heads slightly offset, it seems that at 3mm per side the offset would be slight and with the proper relief in the pistons one could live with this.. I am asking this question before I cut the center out of a set of cam towers and rejoin them.

Frallan · Post by **Frallan** » Sat Dec 15, 2007 3:55 am

That is what I have on my engine. The reason is described in detail in earlier postings on this thread.
It is the topring and valve notch clearance.
I can post a picture in a week, if you wish.
Right now I am travelling and only have my toy PDA to work with.

M-Owen · Post by **M-Owen** » Mon Dec 17, 2007 4:29 pm

Frallen where did you get your cams done? I am going to cut the center out of my cam towers and stay with 124mm bore centers, I have the procedure sorted out and they should be done on Saturday.

M-Owen · Post by **M-Owen** » Mon Dec 17, 2007 4:29 pm

Frallen where did you get your cams done? I am going to cut the center out of my cam towers and stay with 124mm bore centers, I have the procedure sorted out and they should be done on Saturday.