Corey_68

What all is involved in O-Ringing a block and how much nitrous can be sprayed before the block has to be machined? What are they advantages? A fellow racer said he kept blowing head gaskets when he hit the N20 and had to have the blocked O-riged, whicj solved his problem. :confused:

69 N.O.X. RATT

It is more of an issue of peak cylinder pressure than how much of a shot you are running. For example high compression plus nitrous = higher cylinder pressure. I am a believer in over building stuff so I would say if you plan to run nitrous very often and above 150 shot with 10 or more to 1 compression I would O-ring the block. It is pretty simple to do although I had a machine shop do mine. With an o-ringed block you should run copper head gaskets. I run the new SCE Titan head gaskets and have had no problems sometimes associated with coppper head gaskets on the street. They are designed for street / strip use.

Corey_68

I was just curious, what I would be limited to?? I have a fully forged rotating assembly, 10:1 compression, 4 bolt main, ARP rod bolts and ARP head studs. I was looking in the neighborhood of a 200hp shot? I feel this should be somewhat safe considering I take the proper precausions (window switch, fuel pressue cut off, etc) no?? I know fuel delievery may be a concern, though I'm running a 110gph electric pump. I would most likely start w/ a 100hp shot and she how the motor likes it and progress from there.

norvalwilhelm

Corey you will be suprised at how good a 100 horse shot feels. Remember Monty talking about not O ringing the block because he wanted the gasket to blow like a pressure valve if the pressure got too high.
That said I O ringed my block myself with a hand tool and it took about 2 hours. It can even be done with the motor assembled, but of course the heads must be off but the pistons can just me moved down the hole. You are cutting a .040 groove .032 deep for a .040 stainless wire.
Give the motor a try without the O ring and if the head gasket lifts then change it . The heads got to come off anyway for O ringing but the block can stay in the car.
I am not a fan of copper gaskets but I run one and it has worked for me for the last 3 years.
With 100 horse no damage will happen and no changes are required to anything.
I have seen motors drop over 1 second with a 100 horse shot.

69 N.O.X. RATT

I think if you run a stout 454 with a 200 shot both fed by a single 110 gph pump you will melt something. To be safe run a dedicated fuel pump for the NOS or upgrade to a much bigger pump. If you run a dedicated pump rember the pump needs a few seconds to get pressure up before you engage the NOS, otherwise you will have a lean hit, not good

For anything over a 150 shot ring gap may be an issue. For a 200 shot (depending on ring make and material) a gap of .0055 to .006 per inch of bore diameter would be pretty safe. For the second ring increase that by .002 total.

Norval is right a 100 shot is very noticable

I consulted with Norval before I ran the copper gaskets and like I said in the earlier post have had no problems. I highly reccomend the SCE Titans

Corey_68

I appreciate the info fellas. :thumbs: It's not a matter of "IF" but "WHEN" I do buy a bottle, I plan to get a second fuel pump just for the juice. I just want to get "All my ducks in a row" so to speak before I make this leap.

:cheers:

gkull

I have nitrous fan Friends. Yes your total power level is a Factor. O-ringing blocks only seal with thick copper gaskets like .040 or even better .060. Because the o-ring sticks up @ .012 - .018. Water leak and quench height comes in. You start to have to think about "Zero deck" pistons and block strength.

I planned my motor for a 250 hp shot of N2O I have the intake for up to NOS 500 HP. who I got it From had problems of breaking crank shafts at the 375 HP level in his 427 small blocks without O-rings. Your also talking @1000 hp on the bottle with less than the best blocks and cranks.

I have a .021 copper gasket with @ .020 surfaced block

Turbo-Jet

can someone explain (with pics maybe) more about o-ring modification? i have a idea of how it works, but never actually have seen it.

FWIW, i have a friend with a LS6 and a 500 shot, no o-rings. :crazy:

norvalwilhelm

I don't have pictures of course but it is just a groove cut around each cylinder and a stainless wire is taped into the groove. Part of the wire sticks above the deck so when the gasket is installed and torqued down it bits into this gasket forming a seal.
Summit sells a nice tool for O ringing . It does not require power tools and slides into the cylinder bore, clamps on the bore then feeler gages are used to set the depth of cut. You then turn the tool using oil as lubricatant and cut a groove. If done right the groove comes out without any chatter marks.
Summit sells stainless .040 O ring wire so I cut my groove .040 wide and they recommend 20% stick out so I cut my groove .032 deep to leave .008 sticking up above the deck.
The local machine shop wanted about $150 to O ring the block and the tool was about the same price if you bought it yourself.
You guys know me so I did it myself.
You then need to take a soft hammer, cut a length of stainless wire and carefully tap it into the groove. The hard part was getting the end gap where the 2 wires meet to just but up , no gap, no overlap.
I then used the .040 copper gasket with copper spray.