Neal, Headgasket Question
#1
#2
HI!... Well I'm not sure about the FORD MLS but the COMETIC use stainless steel layers, not steel.Plus they are viton coated. I always ran the FORD MLS gaskets and never got more than a year out of them before they started leaking. (OIL) Since I've been running the COMETICS I have not had a problem with leaking at all. Also many TURBO guys running a ton of boost or nitrous run COMETICS and don't seem to have a problem with them blowing out as much as the FORD MLS ones. All I know is I like them.
#3
Unless you are going to have the block and heads machined, don't bother with mls, you will just have problems. MLS needs a very near-perfect surface to seal properly. You'd want to find a machine shop who can stone-grind your block and heads. If you do go mls, go with the Fel-Pro mls. It's a much more forgiving hg. I've seen a lot of people burn their heads with the Cometics, and that's very rare to see with the FP. Keep in mind I'm talking about extreme hp cars with huge sprays or big boost.
But if you are going to make some serious power, just forget about mls all together and go with o-ringed copper. Copper also doesn't need to have the perfectly smooth gasket surface than the mls needs. Double o-ringed copper is the bees-knees in hg's IMO.
With the mls and copper hg's, with aluminum heads, you'll want to go to head studs and a new torque procedure. After every heat cycle (thoroughly warmed up and cooled to ambient), re-torque the heads. After 5 or 6 times, they won't need that anymore and you're all set. If you do that, you won't have problems with head lift which is a big source of headaches with mls and copper (because the hg's don't actually compress).
Also, regardless of what you've heard, if you go copper, you don't have to replace the gaskets if you take off the heads. That's a big plus because these hg's are expensive! The mls's have a special coating and "need" to be replaced if you pull the heads, even though I know lots of people who don't. If you go o-ringed though, you really should replace them anyway, regardless of what their made of.
But if you are going to make some serious power, just forget about mls all together and go with o-ringed copper. Copper also doesn't need to have the perfectly smooth gasket surface than the mls needs. Double o-ringed copper is the bees-knees in hg's IMO.
With the mls and copper hg's, with aluminum heads, you'll want to go to head studs and a new torque procedure. After every heat cycle (thoroughly warmed up and cooled to ambient), re-torque the heads. After 5 or 6 times, they won't need that anymore and you're all set. If you do that, you won't have problems with head lift which is a big source of headaches with mls and copper (because the hg's don't actually compress).
Also, regardless of what you've heard, if you go copper, you don't have to replace the gaskets if you take off the heads. That's a big plus because these hg's are expensive! The mls's have a special coating and "need" to be replaced if you pull the heads, even though I know lots of people who don't. If you go o-ringed though, you really should replace them anyway, regardless of what their made of.
Last edited by tritonpwr; 01-06-2007 at 05:57 PM.
#4
I'm wondering to do just a regular headgasket job on a near stock truck. It hasn't overheated, I think the block and heads will be flat. I will check with a straight edge and use plastic scrapers. So you guys think the Cometic gaskets wouldn't be the best choice for my application. I know Ford redesigned their gaskets to improve the sealing aruund the oil passage in the back of the head when they changed to a MLS gasket. Maybe Felpro would be best? What do you guys think for a stock truck?
#5
#6
Originally Posted by Neal
HI!... Just go with what you can afford. I've heard horror storys about COPPER, FEL-FRO, COMETIC and the FORD MLS head gaskets. None of them are perfect. I've even had problems with the FEL-PRO "LOC-WIRE" head gaskets on my 408, and most guys swear by them.
Now, most of the time people have problems with mls is due to rough mating surfaces, not the gaskets themselves. Those mls gaskets require a damn near perfect surface, not just flat, but almost perfectly smooth (recommended 80MA). They aren't nearly as forgiving as, well, ANY other material. That's the only thing I don't like about them. People try to just replace their hg's with mls and then they're all "WTF!!??" when they blow. You just can't clean the block and head (if their stock) and thow on an mls. You have to have the block and heads finished for mls. On the plus side, mls won't harden like copper does. But for me, I change mine every season anyway, so that's not really an issue.
To the op.... If it's a stock motor, you don't need anything beyond a factory replacement hg. Whatever's in the box will do you fine. At those pressures, you have no need for a >$200 hg. If you want to go over 400hp, then you might consider a nice gasket, but for now, OEM is more than adequate.
#7
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#8
As tritonpwr said, the block and head mating surfaces have to be not only flat but almost perfectly smooth.
Here's the DIY drill with a little sales pitch.
http://www.sa-motorsports.com/gasketdiy.aspx
I hope this helps.
Here's the DIY drill with a little sales pitch.
http://www.sa-motorsports.com/gasketdiy.aspx
I hope this helps.
#11
Originally Posted by Neal
HI!... Here's some good reading. Notice which head gasket 90% of the guys preffer.
http://www.yellowbullet.com/forum/sh...ad.php?t=16464
http://www.yellowbullet.com/forum/sh...ad.php?t=16464
#12
#13
Originally Posted by Faster150
its "Canadian math" = were always right ehh
I guess if everyone wears Nike that automatically makes them the world's best shoe.
"But mom! All the other kids have Cometic! It's just not fair!!!!"
I don't have anything against Cometic. Hell, I don't even mess with mls. If I ran a hot street car, I probably would because copper hardens in places over time and mls doesn't (it's just hard everywhere!). Alls Is cans says about it is that the people I know who used to run Cometic either run copper or Fel-Pro mls now. I guess if you're only making 600, 700hp, probably any of them will do fine. You're not going to find much mls anywhere in the 1500-7000hp range. In the range I'm running in, (>1600 FWHP), I don't know of anybody running mls. Every car I know in that area's running copper. And I know the top-fuelers are running the same head gaskets I am, even the same brand. So I guess Cometic is fine as long as your not too serious about it. Fel-Pro's in the same boat for that matter.
Last edited by tritonpwr; 01-08-2007 at 10:29 AM.
#15
Guys, I just want to replace the seeping "crap gaskets" on a stock PI 4.6. Sounds like the current OEM gasket is best since they were designed to address the uneven surfaces. Does Ford usually have the heads resurfaced? I'd hate to spend all this time / money just to end up with another seeping gasket or two in 20k miles. Any idea when Ford started using these and what the part # is? Thanks.