Modified 6.2 turbo diesel

[chevyinlinesix]

would like to know this as well.

We could start a little poll up, anyone that has/had main web cracks could check their mains for alignment. I can check mine, but it won't be for a Hwhile.

 

[6.2 turbo]

I'm thinking about pulling the 6.2 and getting it oringed ,block filled and going back to stock pistons,and using my very cracked 6.5 heads,and modified prechambers, possibly even custom made prechambers out of chrome molly steel.

 

[GJF]

I been thinking of the o-ring issue. The Swedes have been machining the BMW blocks to accept a large o-ring that has a pyramid shape and it only fits into the block. Nothing is done to the head. This ring provides a structural support for the stock head gasket that creates a dam and doesn't allow boost to push the stock gaskets sealing rings back no more than the pyramid ring is located. This way the sealing ring still seals and no special copper gasket is required. 60+psi with this setup for quite some time and no failures. The reliefs on the block for detonation blow-outs would be optional. A regular stock gasket devoid of the fire ring goes around this setup. 1500HP on the water cooled S38 motor, easily. There is plenty of meat of the top of the 6.5 decks and this would be a very cost effective modification with superior results.

 

[Veg_Out]

I been thinking of the o-ring issue. The Swedes have been machining the BMW blocks to accept a large o-ring that has a pyramid shape and it only fits into the block. Nothing is done to the head. This ring provides a structural support for the stock head gasket that creates a dam and doesn't allow boost to push the stock gaskets sealing rings back no more than the pyramid ring is located. This way the sealing ring still seals and no special copper gasket is required. 60+psi with this setup for quite some time and no failures. The reliefs on the block for detonation blow-outs would be optional. A regular stock gasket devoid of the fire ring goes around this setup. 1500HP on the water cooled S38 motor, easily. There is plenty of meat of the top of the 6.5 decks and this would be a very cost effective modification with superior results.

Would be very cool!

 

[6.2 turbo]

I had also come across this while surfing the internet,it seems they use these with aluminum heads . Not sure if it would work on the cast iron heads,also its simular to the fire rings that is done to the 5.9 cummins ,and they groove the block and head.

 

[GJF]

Of course it would work with cast iron heads. These are not like a fire ring but rather a dam to reinforce the stock gasket. This way there is no need to groove the heads or deal with the water jackets leaking with the copper gasket.

 

[6.2 turbo]

I think it has to seal perfectly on the head ,since it seems that they remove the original stock fire ring ,and replace it with the pyramid ring,and the top edge seats into the soft aluminum. It might work on cast iron,but thats not the only problem,I would have to get them custom made at a machine shop,since I don't no where to buy them.

 

[GJF]

They don't remove the original stock ring... The pyramid ring only sticks up slightly and supports the outer portion of the stock ring so it can't be pushed back from boost. The pyramid rings are custom made per application they aren't ready made.

 

[chevyinlinesix]

I'm thinking about pulling the 6.2 and getting it oringed ,block filled and going back to stock pistons,and using my very cracked 6.5 heads,and modified prechambers, possibly even custom made prechambers out of chrome molly steel.

That would be several steps backwards.

 

[6.2 turbo]

Looks like there is two styles cut rings and pyramid rings,seems there just made for Bimmers.

 

[GJF]

It's just something the Swedes have been doing on the BMW's. They are pretty good improvisers making something work better. Just like o-ringing any engine they need to be custom machined. I understand the physics of the pyramid method and thought it would work well for your level of boost. It's a fancy way to seriously reinforce the stock head gasket flame ring.

 

[6.2 turbo]

That would be several steps backwards.

Why is that ?

 

[chevyinlinesix]

Why is that ?

Well, there is thermal expansion to consider, cycle life, melting points, basically every aspect of the metal to consider. A typical Chrome Moly steel (depending on grade) has much higher amounts of carbon in it. The factory original precups are made from Inconel© as far as I know... either that, or a 300 series stainless, both of which vastly out-perform chrome. There is a material that I am considering using, but lets not say right meow

 

[6.2 turbo]

I'll probably modify stock pre cups,it would be cheaper anyway stainless would work,this is what performance intake and exhaust valves are made of,never seen one melt.

 

[GJF]

Inconel by far, is able to withstand far more abuse than any 300 series stainless. Modifying the Inconel cups would be advantagous. In case you didn't know in general, turbos turbine impellers are all made using Inconel. It's melting point starts at 1600°F. In racing turbos pupose built they have used Titanium.

 

[6.2 turbo]

That's good to know. I was thinking of hardness and overlooked the melting point ,which is the real issue, although did you ever try to cut stainless with a torch, its not very easy.

 

[ak diesel driver]

with all this talk of inconel maybe someone ought to verify what it really is there was another thread by a machinst who stated they were not inconel or he wouldn't have been able to machine them. I believe it was Hank48s thread about porting precups.

 

[GJF]

Yes no torches on stainless unless I have to. I usually have my stainless parts CNC water jetted. They come out so clean and NO slag.

 

[GJF]

For many years, Inconel has been used for Formula One and Champ Car exhaust systems. More recently, several Winston Cup racing teams have utilized Inconel for producing ultra-light, high-durability exhaust headers.

Burns Stainless recommends Inconel 625 alloy for exhaust systems due to its excellent strength, corrosion resistance and fabricability. This alloy also exhibits high creep and rupture strength; outstanding fatigue and thermal-fatigue strength; as well as excellent weldability (though the guy welding it might have a different opinion!). Inconel 625 contains molybdenum and columbium, which stiffens and strengthens the nickel-chromium matrix without precipitation hardening treatments. Some hardening however does occur when heated to intermediate temperatures (1200 F to 1600 F) increasing room temperature strength. Also, this alloy retains over 75% of its room temperature strength at 1200 F. This alloy is available in a wide variety of forms including tubing, sheet, bar, plates and castings. Burns Stainless typically stocks welded and drawn Inconel 625 tubing. The tubing specification is SAE AMS 5581, Nickel Alloy, Corrosion and Heat Resistant, Seamless or Welded Tubing.

Inconel 625 can be welded using conventional stainless steel TIG welding techniques. Inconel Filler Metal 625 rod is used to weld Inconel to Inconel as well as to dissimilar metals including stainless steel. Inconel weldments are high strength and are highly resistant to corrosion and oxidation. Many welders describe that welding Inconel as "dirty". In other words, the weld pool appears to be under a "skin" and is not well defined. In addition, the weld pool is somewhat "sluggish" as compared with steel or stainless steel. These characteristics tend to result in a "coarse" appearing weldment as compared to stainless steel. Welding Inconel is not necessarily more difficult to weld than stainless, just different. By following the welding procedures outlined in the header construction tips article, successful welds with Inconel 625 are possible.

 

[GJF]

AK it is machinable but not easy. It is very slow going and then again it depends on which alloy.