IMO OEM gaskets are fine, mine went after 3 years of straight abuse, nitrous run through a VGT is a lot of back pressure and cylinder pressure im sure, especially when I ran it for 2+ years on a stock charger, it took 2 stages of nitrous on a VGT to pop the head gaskets. If they are done right, you will only have to do it once. When I build my next engine it will have OEM gaskets with ARP 625's. I have seen trucks with 600+hp running OEM gaskets for years without any issues, and with the occasional spray. Just my 2 cents and my experiences with them.
I understand exactly what you are saying and I hope you are right. I know we have spoken through a couple of pm's and I have talked with Chris a lot on the subject. I know Jesse Warren is also going to try going that route and I hope it works great!
The problem for me is that I don't know any guys that have been pushing 600+ hp that actually use it and had their head gaskets last very long. I only know guys who say they know guys? Or guys who have 600hp trucks that never go over 1/4 throttle (Nate
) A lot of the guys that I know pushing 600+ hp and actually use it are usually tearing down their trucks all the time and replacing the head gaskets anyways while they are in there. Mike I thought yours blew very soon after you put on your stage 3 turbo? Do you know if it was leaking before? In my case my head gaskets were not blown. They were only slightly leaking. You would not have known unless you put a pressure gauge on it. But a slightly leaking head gasket will eventually lead to a blown gasket over time, especially if you add a bigger turbo to it.
Most of the gaskets I have seen blew out around the fire ring sealant area half way between the studs. This is because the heads will flex between the studs (no matter how strong the stud is). That is a huge down fall of the MLS style gasket because when the pressure releases slightly it will start to burn/rub off. That sealant can be great if it leaks slightly then when the pressure lets off it will seal right up again. But it will eventually wear out and then the flood gates will open.
Here is a very good read on why copper head gaskets hold up better in high hp applications
Copper Head Gaskets | AERA Engine Builders Association
Here is a quote from the article that is why i feel our stock oem gaskets fail the way they do...
"To an engine builder, the words “High Performance” pre-suppose high pressure, high pressure requires a more robust combustion seal and the best combustion seal is metal-to-metal. I’ll elaborate; many cylinder head gaskets are coated with sealants designed to eliminate fluid leaks. From experience, readers of this article will be familiar with the various types from slick to sticky and while these work well for fluid sealing they are not able to withstand combustion pressure and heat. No matter how good an elastomeric coating may be for coolant or oil, it will eventually scrub off, burn off, or blow off the fire ring area of the head gasket and in performance engines this can happen in a surprisingly short period of time. Once the sealant is gone from the fire ring combustion seal, it’s a short trip to the nearest coolant passage. Silicone, or other rubber-like sealants or coatings should never be placed on the combustion seal in performance engines."
Here is a picture of my last set of blown gaskets. You can see it failed just like the article states. The sealant just started wearing off. Once the sealant is gone your head will leak.
This is why I have chosen not to go with the arp 625s and OEM gaskets. The extra clamping load will not stop the head from flexing under load. ARP 625s will only help to keep the studs from stretching under load. When the heads flex under load the sealant will start to wear/burn out. Once the sealant wears out your heads start to leak slightly... which will eventually lead to a blown head gasket. This is why IMO many guys push huge power for short periods of time with standard ARPs and OEM gaskets. But I know very very few (actually no one) that pushes high hp on a DD for more that a few years with standard OEM gaskets.
This started me looking into copper gaskets. These are an awesome choice and are used by many of the top drag cars. The biggest drawback of a metal to metal gasket is that it does not seal the water/oil chambers very well. This does not matter to most guys pushing high HP drags because they are always tearing down their motors and only run them for short periods of time. I liked the metal to metal sealing around the combustion area but I dont like the potential problems from leaking water and oil.
This is what led me more to the Fire ring idea. You get the benefits of a metal to metal seal around the combustion area. Then just outside the combustion area you still have a graphite gaskets which have worked great for decades to seal oil/water chambers. It seems like the best of both worlds in theory... but we all know things don't always work good in theory and application
Hope that helps explain what led me to this idea