At what point do you need to machine the block for o-rings? Is the there certain amount of boost? Or how much is it dependent on HP/TQ? Whats the deal?

Cylinder pressure is what it comes down to. You can run big boost w/ a low compression piston and not need to o-ring the block. Be gentle w/ the timing advance, watch your intake temperatures, and don't get lean. I wouldn't start to think about it until past 650 rwhp in any case, since head gaskets could be a safety valve instead of breaking pistons w/ detonation.

I'm going to run 8.2:1 forged JE's so I should be alright. Procharger says it could be 1000 plus easy(not at the wheels) and the bottom end will take up to 1400hp.

uhh yea, i'd get it cut for o-rings and use head studs for sure. A very good quality head gasket as well, cometic or such.

I hope that you've got a strong lower end too. 4340 rods and crank, for sure. 1100 is a lot of ponies for a regular block. If you go past 650, I'd definitely recommend a Dart block or something like it. Even the old high nickel GMs would be limited to around 700. Anyway, since you didn't say anything about the bottom end, I thought I'd put my two cents in.

Roarin_Mouse

Huh…

Usually you only run lockwire/o-rings grooves with copper gaskets and gaskets like the fel pros that are designed to be used with a receiver groove. As far as I know they are totally inappropriate for something like the cometec or felpro MLS design.

The second question is do you want to cut the head, block or both? I’ve always heard that head or block doesn’t matter as far as function, but of course, you can cut the heads any time, even with the engine in the car, but the disadvantage is that they need to be recut if you deck the head, and now suddenly there are builders turning up with setups that have both cut (for example, nelson racing engines cuts one, puts the ring in it, bolts it down and uses the impression as a pattern to cut the other).

I run 9.6-1 compression, and 21# of boost. I had the Felpro lockwires on my old heads, with no problems, now I am running Felpro MLS gaskets with no complaints. I would recomend running Cometic or MLS and not cut the block or heads. DonB.

I’m curious Don, did you have any issues with your installation with the felpro MLS gaskets?

We used a few of the earlier ones and ran into all sorts of small issues. The 2 that I remember is that they didn’t have the cutout for a driver’s side dipstick tube and that some of the rivets were located in a location that they got caught between the head and the block which we were wondering if it would either keep the gasket from properly compressing or brinelling the aluminum heads in that spot.

The reason that I’ve played with copper + o-rings is that it seems to me that a good 85% of what I get near seems to have the pistons deep enough in the hole that we’re looking for <.035” thick gaskets all the time and the copper ones are easily available down to the .02x” range. I haven’t seen any MLS gaskets thinner then .038”. I keep hearing the rumor that they can be had that way but I can’t seem to find any, I know felpro won’t do it, I’ve asked them.

I guess I should have mentioned the forged 4340 Scat assembly. And definatly running studs through out. Good info, thanks.

I have had no such problems with the Felpro MLS gaskets.
I can add that I ran standard felpro gaskets, and would blow them every second or third pass, put the MLS's in and have made 15 passes without issues.
DonB.

How much boost are you running Blownbird? I was looking at Fel-pro's website, I didnt see MLS gaskets. Is it a new Item? Where did you get yours? Thanks

Hum… Don, how long ago did you do them? Like I said, the sets that I had experience with were probably the first few they made and I suspect based on our issues with them they would have redesigned them if they had any sense. Do you remember what thickness the ones that you used were?

I just blew a $180 Fel Pro on my DSM. 25 PSI on a 50 trim turbo, pissed me off fo shossss.

im planning on getting near 30psi, and i have the sce multi layer copper gaskets.......no o-ring for me........preston smith has run them as well in his world famous turbo iroc lol.....he actually persuaded me to try them

hes making around 950HP and he hasn't had any probelms with them at all........he also didnt have any trouble with his stock block until around 900hp.......i saw that someone commented on that......850 should be fine with a decent factory block.

if you're not sure when and where an o-ring application is needed though, you might want to reconsider building an engine like that and do alot more research and questing for understanding first.

Hum (confused)

SCE has a number of different styles of gaskets that partially match your description there. They have their copper Titan gaskets, ICS Titans and I believe they have an MLS gasket. I believe that you’re talking about one of the 2 titans… the normal titan is just a copper gasket with printed on sealing beads so that you don’t have to use other compounds to seal the coolant passages, as far as I know, these are supposed to be used with an O-ring in a cut receiver groove (though I have heard rumors that they work without the ring. The ICS titans are the same with a steel o-ring between the top and bottom copper layer that compresses into the copper layers and does not use a groove cut in the head or block… Which one are you using?

i'm sorry.......they are the titan self sealing copper gaskets, they have seals bonded to the fluid passages on both sides, not the MLS ones......i was half asleep when i typed that last night apparently, i dont know where the hell i got that from lol

heres the gaskets on summits site.....

SCE Titan Copper Self Sealing Head Gaskets: SCE-T11064 - summitracing.com

they don't require any machine work or lock wires either.

If I'm not sure if I should O-ring it or not I should do more research? What do you call this thread? Research perhaps?

you really don't need to, the newer gaskets like the SCE ones im using are getting so good now that needing to do so is even further away than it used to be.

i know several people using these gaskets with no problems....making around 900hp

I am making 1300+ horsepower with the Felpro MLS gaskets. It would be crazy to think you would need to cut the block or heads to get a good seal!

well played sir lol

Cant seem to find a good enough machine shop around me that even knows about o-ringing. So I guess its good that I wouldnt need it for the boost I'll be runing. Blown bird what block did you use? And how much boost does it take to make that 1300?

I am using a Dart little-m and am running 20-21# of boost.

gas or alcohol? and what are you using for a cam?

im going to max out the f1-R and see what happens lol