Flame ringing cylinders/barrels?

[JMA-RUF]

As the subject states, what do you guys think of such a mod for big boost motors running at around 1.4bar?

Is it still required, even if you use high quality ARP fasteners?

Is the expense worth the extra insurance?

[David]

I'll assume you mean between the cylinder and the head:

At 1.4 bar I'd think it was mandatory.

Even at 1 bar, it's a really good idea.

[JMA-RUF]

Thanks - just trying to toss up between an extra point in compression for off-boost response, or leaving it at 7.0:1 and having the flame ring mod done to support more boost.

I think I'd prefer more boost

[spjuvern]

is this 1 bar rule also for the 965 engines that have a head to cylinder gasket?

i am thinking about those flame rings to my engine, what different options are there?

[JBL930]

Even in the 993tt they say go no higher than 1.1bar to be safe on an otherwise stock engine

[JMA-RUF]

Originally Posted by JBL930

Even in the 993tt they say go no higher than 1.1bar to be safe on an otherwise stock engine

993tt runs higher compression than the 930... I'm talking about the 930 7.0:1 motor here, not a 993TT.

spjuvern, the 965 motor already has a sealing head gasket, which offers better sealing than no head gasket at all (from what I'm told), but flame ringing offers the best sealing at very high boost levels.

[JBL930]

Originally Posted by JMA-RUF

993tt runs higher compression than the 930... I'm talking about the 930 7.0:1 motor here, not a 993TT.

spjuvern, the 965 motor already has a sealing head gasket, which offers better sealing than no head gasket at all (from what I'm told), but flame ringing offers the best sealing at very high boost levels.

I'm well aware what motor you are talking about, i was simply stating that even two generations further along 1.1bar was seen as the limit for a stock engine.
With the stock 930 engine i'm told that anything above 1.0bar will cause issues, so anything above this will need head sealing along with other mods to keep things together.
I think running an air cooled engine at 1.4bar is suicidal, unless it's a race engine that is stripped and rebuilt like clockwork. For a street engine 1.2bar is the upper end of the envelope, and requires more than just head sealing for longevity.

[onboost]

James..

Personally I'd do both.
- 7.5:1 is a nice bump to get a little low end grunt.. (add SC cams)
- Flame rings are nice "while you're in there" insurance..

Then you've got the best of both worlds.. not too radical, but a nice bump with a safety factor..

Just to note:
- Have a bud that did 8.0:1 JEs, flame rings etc.. runs at .8 bar and it's twin turbo'd

- My current motor 3.5 Ltr, 7.5:1, flame ringed, and is set at 1 bar.
No issues and runs like a scalded dog!! That is if I can ever finish my other little mods and clean-ups and get back to the pavement.

Hope that helps..

[JMA-RUF]

I read somewhere Juan Ruiz was running flamed rings and was running some pretty extreme boost (1.4+ bar) on his Carrera motor.

I'm told for a street car that sees occasional boost, it'd be fine?

Mind you, this is for an EFI'd 3.3 Carrera motor, not CIS.

[strokher racing]

The same guy who did Juans heads did mine. Juan runs a bit more boost than that It is alot more than boost to consider. 22 pounds from a k27 and 22 pounds from a t76 are two different beasts.

[Craig 930 RS]

After seeing the heads skip around my cylinder barrels - I'd say it's a must for .9 and above and cars which see track use.
I have em.

[TimT]

Even in our race cars we tune the engine in the 0.8~1.4/1.6 bar range ... and limit the boost at 1.4, and don't recommend operating the engine for long periods at 1.4
I know Bill drives his 935c at 0.8 mostly..

Putting 670 hp onto the dyno @ 0.8 is cool.. blistering the tires and loosing accuracy @ 1.0+ is way cool.

Nirosist rings are a must do "while you in there" mod... the only con is the extra expense, the pros are less expense in the future...

[DonE]

Not many know how to do this mod correctly, so beware. I flame ringed mine for the same reason Craig mentioned.

My rings are made of stainless and are cut .001 taller than needed for proper compression and even fit. The mod requires at least ARP head studs - no stock Porsche stuff.

Once you do the mod, you'll have to cut any new heads or cylinders from here on. Before you say you won't be buying any new cylinders or heads, you might want to reconsider 1.4 bar. You can eat pistons and cylinders within the blink of an eye at that boost. I have the scrap metal to prove it.

[Craig 930 RS]

I think it was about $800 - for the work and tooling involved, it was a bargain - pics soon below.

[Craig 930 RS]

Flame rings installed in barrels:

[JMA-RUF]

Great pics, Craig. Thanks

I remember reading that Protomotive made their rings out of some sort of aluminium, so they have the same expansion rate as the other metals around it?

[spjuvern]

how about this rings http://www.cometic.com/files/CometicPhuzion.pdf

any one had a experience with Porsche engine and those?

i have them in a Lexus twin turbo V8 we built

[fredmeister]

Cant you alleviate the heads moving around under higher boost pressure by increasing the head stud torques? Of course this requires ARP studs for safety, but the mean effect is increasing the compressive preload on the cylinder head so that you don't get separation between head and cylinder at high boost pressures.
I know that flame rings are a better solution, but the cost and stuff outlined above is a factor, when switching to higher quality studs and increasing torque is cheaper, since likely you would switch studs during a rebuild anyway.
Thoughts?

[Craig 930 RS]

Already used ARP studs - they move around like you would not believe - .8 bar and hard track use.

If I were doing a new P&C rebuild and my car saw track use, the rings would be a 100% no-brainer.

[juan ruiz]

Absolutely Niro Rings and studs why limit to 1.4 bar try 2.0 bar you will fall in love